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Archived 7 Mar 2006

Surprised to see a plumbing article on a MoneySaving site? Don't be, plumbing is very expensive and if you can do it yourself, you'll save some cash.

Many plumbers are good guys (and gals), but there are some out there who cost large. This article all began when I asked Ian Puddick, media plumber ( ie, he appears doing plumbing on radio & TV!) if he'd agree to answer some users' questions one week, as an experiment to see if there'd be a demand.

So I put 'free plumbing questions answered' in the weekly Martin's Money Tip e-mail and we were swamped (see the original thread). The following is the result, so unlike every other article on the site, the answers below are Ian's not mine. And I should say I agreed to tell people in London that he has a company, Leakbusters, as part of this.

This was written in 2006. However, as most of the tips are practical ones they should still stand.

Disclaimer OK, let's be honest. This is a general article, for questions people have written in; neither nor Ian Puddick can take any responsibility if there are problems when using this info, either correctly or incorrectly. On your own head be it.

Fixing your toilet

I have two extremely noisy toilets when they flush and the cistern refills, is there any way to shut them up?

You can install a torbec or fluidmaster silent fill valve – these valves are a universal fit and will replace your existing ballvalve.

The level of water in my toilet seems to be gradually decreasing. What can I do?

Look for a hair line crack in the cistern, if you cannot find a leak change the siphon.

How do I stop the overflow from my toilet-it has a plastic ballcock but the water level keeps drifting up to the overflow level.

Change the washer inside the ballvalve by first isolating the water supply. Unscrew the body of the valve and take it to your local plumbing merchant. They will probably give you the washer.

It now takes about five pulls on my cistern to get the flush to complete. I have heard from an unreliable person that I need a new Flap Valve. Is this true? If so, how do I fit it?

Uuumm….It sounds like you have a high level WC cistern, if so it will probably be quite old. If it is you need to replace the whole siphon unit. Remove it and take it to your local plumbing shop who can match it up. It is a relatively simple job.

I am about to install a new bathroom suite but I am unsure how to take out and fit the toilet.

Isolate the water supply to your toilet either at the loft tank if you have one, or the cold supply to the property. The WC will usually be fixed to the floor by 4 screws, if it's a concrete floor your WC will be cemented to the floor so it will have to be smashed out. Unscrew the copper pipe connection to the ballvalve on the cistern then ease out the WC from the outlet spigot. I recommend replacing this as you may have leaks there in the future. The process should take DIY'er 30mins.

I have an outside loo that I want to move a few feet to create more garden space. How do I do this?

I cant answer this question by text as there are technical issues concerning the drainage, however assuming the drain is staying in the same fixed location you can buy a 4” flexible WC pipe outlet and a few 4” push fit plastic connectors, if you go into your local plumbing shop with picture/digital camera and show them what you are planning to do they can give the appropriate fittings – its an easy DIY job if the drain point is not going to be dug up.

I'm having real trouble with repairing a closed coupling toilet cistern. It just keeps leaking through the 'doughnut'. I'll give it one more try if you could give me any tips for re-doing it please, before I call in the professionals!! How much should I expect to pay a plumber for this job?

You can buy a close couple kit from a plumber merchant, there are several sizes of the ‘doughnut' washer' – it will leak if you have the wrong size. Don't listen to anyone that tells you to patch up with mastic; it will only leak again in the future. If you know the make of your WC go to your local plumbing merchant.

I am about to buy a new bathroom suite, is there anything I should look for to ensure the toilet has a good flush?

Make sure the cistern will give a 9 litre flush – most are set to 6 litres. (I recommend you buy a turbo 88 siphon for approx £14)

Our main bathroom is on the first floor and every time the toilet is flushed there is a really foul smell, mainly in the kitchen which is directly below. The smell is much worse when the toilet hasn't been flushed for a while (i.e. 1st thing in the morning, 1st flush after getting home from work/ holidays away etc) and doesn't seem to bear any connection to what was being flushed away - for want of a better description!

I'm sorry I can't really give you a prognosis on this – I recommend a professional has a look.

Problems with your bathroom

The water from the upstairs bathroom tap is starting to come out brown and smells and tastes stale. What can we do?

Shut off the water supply to the ballvalve and drain your cold water tank. Open up the taps in your bathroom until the tank has approximately 6” of water left at the bottom of the tank. With a scrubbing brush and a little detergent scrub all the walls and base of the tank then open up the supply to the ballvalve, turn on the taps and let the water flush through from the tank down to your taps. Make sure you have the appropriate cover on your tank to stop dirt and debris falling in. Should this fail, contact your local water authority who will send an engineer to test the water quality.

I am going to resurface my bath rather than replace it but I need to replace the taps on the bath and the sink. Should I paint the bath then change the taps? How do I change taps, what tools do I need? My House is a 1970's ex council house with copper pipes. I have no plumbing experience.

A good quality tap spanner will cost about £30, I would engage a professional to carry out this job as it can very tricky and potentially cause a leak. The job should cost you approx £90.

Our shower is one of those cheap wall-mounted over the bath things. It will only produce scalding hot or freezing cold water. Is this just because it's cheap? How much would it cost to put in a proper shower? I'm not planning on doing it myself but I would like to know so I can ask my landlady.

I would recommend a thermostatically controlled bath shower mixer valve cost approx £270 for a good quality one and approx £160 – 200 for labour.

I installed a shower unit in my en suite, because the size of the gap was c20cm wider than the shower tray itself, I built a bridging shelf which overlapped the shower tray. This was then tiled and plenty of mastic applied. However, water pools in the corner of this shelf causing a leak. I have reapplied the mastic (removing old first) but the leak is still there. I have been advised that the only way to get rid of it is by increasing the angle of the run off into the shower tray so that water does not 'pool' in the corner. Is there anything else I can do to ensure a waterproof seal on the shelf?

Nope (sorry).

Our pipes are extremely noisy. When you empty the bath you can hear the water in the loo and bubbling up the sink. Is this just because the pipes are old? Is there anything we can do about it? If we need new pipes how much is this likely to cost?

I would advise you to get 3 estimates on this issue. Without knowing the pipe work system in the house, flat or block it's not possible to give you an estimate of how much it will cost you.

I want to boost the power to my electric shower? In the shop there was a choice between electric showers and power showers. What is the difference? Can I only connect one sort to a certain type of water supply? I have a combination boiler but the electric shower gets cold water and heats it up. Help!

Your property operates directly from the water main; sadly there is NO pump available that will work from the water main. For a good shower you ideally need approx 3bar water pressure and a min of 15 litres per minute of water flow, ask your local water authority to send an engineer to check your incoming water pressure. You may find that the outside stop cock is not fully open and therefore you are not getting full pressure which can often happen.

I want to change the layout of my little en suite. The house is about 15 years old. What can I get my husband to do as DIY (he can do most things but has not done something like this) and what do I need a professional for? I want to change the shower from electric off the mains to a power shower, change the tray and enclosure from a 760 square to a 900 quadrant in the same place, move the toilet from the internal wall 90 degrees right onto the outside wall and move the basin 90 degrees left from the opposite internal wall also to the outside wall beside the toilet?

I would recommend you get 3 quotes from local plumbers for this type of job; the electric shower MUST be installed directly to the existing fuse box. Tell them that your husband is willing to carry out some of the more mundane (but necessary) work and that should help reduce the cost.

I want to fit a mixer/ temp control unit to a shower head. The shower head is 6ft from the shower incoming H/C. This is so I can set the water temp then get under. What sort is the best for a bathroom 10x10ft, with WC? I have arthritis in my hands.

I don't know what type of system you have in your home (tank fed or directly off the water main), however, I recommend a THEROMSTATICALLY controlled blending valve is installed on the hot and cold supplies to your shower. This will ensure you do not get scolded and have a consistent temperature at all times

Our bathroom sink and bath get regularly clogged. Which is the most effective method for clearing this? The usual brands only work for about 1-2 months.

It would seem that there is partial blockage or that there is insufficient fall (the angle at which the waste pipe slopes away from the property). You will need professional advice on this. I suggest you obtain 3 quotes from local plumbers.

Sometimes when the water in the sink is left running, it starts coming up the bath waste. What's causing this?

It would appear that there is partial blockage or that there is insufficient fall (the angle at which the waste pipe slopes away from the property. You will need professional advice on this. I suggest you obtain 3 quotes from local plumbers.

I live in a very hard water area. How effective are the magnetic/electric gadgets that claim to prevent scaling? Is there a cheap alternative?

Difficult one!! I'm not convinced about there effectiveness, however I can recommend the electric version. You buy the kit which comprises of a bendable wire which you coil around the pipe and plug in. The low voltage creates an electro magnetic field which de-ionises the neutrons in the water make (It would appear I'm turning into a train spotter!). Mini water conditioners are also available which you would have top up approx every 12 months depending on the number of people using your water supply. Both units cost approx £45.

Every time I shut off a mains cold water pipe in the house, there is a knock. I've tried lifting up the floorboards and jamming any wobbly pipes with polystyrene or pipe clips, but it still persists.

Try replacing the ballvalve in the main cold water storage tank. Look for loose pipes again and finally replace the body (internal section) on the incoming stopcock. If the above fails you can buy a mini anti-shock valve, this has a mini expansion vessel that prevents water hammer, which is the problem you have. Good luck.

I have 2 Aqualisa Aquastream power showers nearly 8 years old. One in the bath room and one in the en-suite. The one in the en-suite was continually running cold after presetting the heat controls and it sounded like the pump was cavitating when it lost temperature. I have turned down the thermostats on both the hot water tank and the boiler to stop it aerating the water. I have run the shower on its highest temp setting for 5 minutes and checked the inner hose for kinks as per info from manufacturers, along with any in line strainers. However, still the same problems. Taken the shower apart, cant see anything wrong, put it back up and now temp control consistent, but the pressure on the outlet of the shower head is poor. About half the volume is being delivered. Please find an answer for me as these showers ain't cheap to replace.

Change the internal cartridges inside the valves, generally they are excellent showers.

What are better, steel or acrylic baths?

A very subjective question. Plastic by its very nature will start to move over the years with the weight of people stepping in and out and expansion caused by hot and cold water. Steel will last longer and retain its colour……sorry plastic bath people!

If buying a bath I recommend an extra thick steel bath, which is the same as a standard steel bath apart from it is manufactured with thicker steel giving a superior feel for not much money.

Our shower of four years has stopped being hot. Super pressure, but completely cold. Do we just replace it, or can we do something about it?

It depends on who the manufacturer is. It's a minefield repairing showers, as they are all different. If you do know who the manufacturer is, contact them and request a new thermostatic cartridge, if you don't – seek professional help

My bath is draining very slowly, 12 hours after a bubbly soak. I've tried standard unblockers to no avail. Any suggestions?

It would appear that there is partial blockage or that there is insufficient fall (the angle at which the waste pipe slopes away from the property) – you will need professional advice on this. I suggest you obtain 3 quotes from local plumbers.

I want to install a shower over my bath but my bathroom has been tiled fully floor to ceiling and I don't want to smash the tiles up. What's the best way to do it?

Easy – install a Thermostatic bath shower mixer valve – this is basically a bath shower mixer tap with built thermostatic control (a lot hotels now install them) Look out for Aqualisa and Mira, they both manufacture nice looking and very robust taps.

I have an electric shower in my flat (one of the basic Mira ones) and when I turn the dial off it often stays on for up to 30 seconds after I turn the dial.

New shower required…. sorry.

I have a shower cubical with a hinged door. The furr (brush seal) along the length of the hinge side and the small seal between the brush seal (up stand) and the hinge along the bottom have worn resulting in the water streaming from the bottom corner of the door and finding its way to the ceiling below. I am in the process of getting replacement seals, but is this a simple job, or should an expert be enlisted for the job?

You can carry out this job, remember, when changing the seal, first make sure you clean the area up removing any mastic or silicone.

I have a leak from what appears to be my dirt pipe; this is located in my loft as my bathroom is in the centre on my house. Can you advise me the best and cheapest way to fix this problem?

I'm not sure what you mean by the term dirt pipe, however, if it's the overflow pipe in your loft that is leaking which is very common, turn off the water at the stopcock that feeds the ballvalve on the loft tank, remove the ballvalve with a spanner (you will require two spanners, one to hold onto the body of the valve and one to turn the nut on the pipe connection). Take the ballvalve down to your plumbing merchant and they will give the appropriate match. Approx cost £7.

Tips on taps

My bathroom basin taps have come loose and move about in the hole in the basin (the pipe is still tight in the tap). How do I tighten them - the recess in the underside of the basin is quite narrow and I can't get a spanner up there. Is there a special tool needed?

You need to buy two plastic top hat connectors, these are small plastic connectors that fit under the basin and locate between the tap and the nut which secures the tap to the basin. They cost 30p each and yes you will need a tap spanner which is designed for the job.

The bathroom hot tap has to be turned 2 or 3 turns before it will start running. After that it works fine.

Turn off the hot water at the stop cock, remove the body of the tap and change the washer.

My brother has fitted my bathroom in and all is fine but both my hot and cold taps if left on run boiling hot water and no cold

Whoops, it would appear that he has installed the supplies both into the hot pipe, if not, check to see if the pressure is equal on both taps. If you have a combi boiler the hot should come from the boiler and the cold should come from the water main. If the hot was from a combi but the cold was supplied from a water tank, the low pressure cold water supply to the cold tap would be forced back by the high pressure hot water supply thus causing your problem.

I have some taps which are a few years old and the tap tops are breaking and need replacement. They have the letters 'BB' on them and I think the first 'B' stands for Barking. Nobody seems to stock these anymore because they are so old. Are you able to help? The cross section of the tap where the top fits is square and about a quarter inch across.

Sounds to me like they are Bristan Taps. These are a good tap manufacturer, isolate the supply to one of the taps, unscrew the body and take it to your local plumbing merchant they'll be able to match it up for you.

I have a dripping hot tap in a cloakroom washbasin. Not being entirely hopeless I attempted to change the washer. After undoing the retaining screw the remaining part of the tap (the headgear nut?) was absolutely stuck fast and could not be shifted at all. What is the next step? Will the entire tap have to be replaced and does this involve removing the hand basin from the wall?

Go to your plumbing merchant and purchase a pack of tap revivers (each pack has two), it contains new bodies and all the bits you will need, they are fab and the job should only take you 20mins.

I recently fitted new taps to the sink in the bathroom, (single mixer). Since then I can hear water going through the pipes, and have to leave the tap slightly on and dripping, or else the overflow from the tank in the attic drips out. All cold taps come off the mains. The tank in the loft is only used for hot and central heating.

Change the ballvalve in the tank. However first check that the water in the tank is cold, if it is very warm or hot contact a professional as there will be a problem with your heating system.

We have a tap which although the insides have been changed still refuse to flow - the stopcocks in the loft have been checked and are fine and fully on, but the taps still refuses to give anything but a drip. Any ideas?

Check the washer inside the tap and check the valve in the loft is fully open. Sometimes the valve will appear to be open however it can be jammed almost shut. Isolate the supply, remove the valve and check. The cause could be an air lock – if every other tap works except the one in question there could be a fault with the tap, if so replace it.

How do we make the water from the bathroom taps drinkable when it is attached to the header tank rather than the mains?

The only way would be to connect up the mains supply in the loft directly onto the down service to the bathroom, before you do this make sure there are no pumps fitted the down service and that the pipe material is suitable, if it is an old lead pipe do NOT do it as the pipe may leak.

The cold water tap on my bath has suddenly become very stiff and I can't turn it on. It has always had a really good water pressure but now it literally won't turn. Is there something simple I can do to fix it?

Isolate the cold water supply, remove the body of the tap, re-washer and clean up with lubricating solution. WD40 should do.

How do I stop a tap from dripping?

You need to change the washer. Isolate the water supply, remove the body of the tap with a spanner and fit a new washer.

How easy is it for an ordinary person (like myself) to replace mixer taps (with shower attachment) on my bath? I just want to put a working set on in place of the old set.

It's tricky (personally I think its one of the worst jobs on plumbing), you need to isolate the water. You will need a basin tap spanner to loosen the nuts on the taps.

Tip – make sure you install a new FIBRE washer on the tap connectors otherwise you will have a leak in your hands.

When I run the hot tap fully open I can easily run a bath for my young children without using any cold (as it is only luke warm water) but if I want a hot bath for myself I have to turn the tap on a small amount so it takes forever to fill the bath. Any ideas on what the problem could be?

I guess you have a combination boiler in which case there's not a lot you can do. However if you have some spare dosh (its expensive) you can install a water storage tank and install a pipe to a single impeller pump and then install a pipe from the pump to the boiler. This should stop all your pressure problems and give you excellent hot water.

Are the taps sold in some DIY outlets in cheaper 'trade packs' inferior in quality to the more expensive taps, or is it just a question of style?

The larger DIY chains tend to be profit orientated so in my opinion quality does tend to suffer. Go to a local plumbing merchant and have a look at a few brochure and samples taps. Bristan manufacture quality taps at reasonable prices.

Central heating

I have a traditional gas fired central heating / hot water system, with a header tank in the attic, boiler in the kitchen, and hot water cylinder in the first-floor airing cupboard. There is a switch on the control box that lets me select "heating and hot water" or "hot water only". But just lately, it makes no difference which way I set this switch ... the central heating stays on anyway! What could be the cause of this problem?

The motorised valve in your property needs to be replaced.

I have silly night storage heaters that are useless so I am going to replace with a new combi boiler. I've seen a great deal on for all the kit but would need it fitted. How much should I expect to pay? All copper and fittings are included. Also the Mrs wants old cast iron looking radiators (against my advice!) but they look like they take a lot of water to fill - pushing running costs up. Is this the case or do they generate more heat to balance things up?

Ultimate Discounting offer great deals on whole central heating packs but before you proceed please check your water pressure (min requirement 2bar and flow rate 12 litres per minute). As this will be a big investment I would recommend you get a professional to test your water pressure and take a look at your system. You will only be able to install a CONDENSING combination boiler and bear in mind all gas work must be carried out by a Gas Safe registered installer. The radiator issue is subjective – they will cost more than standard radiators and will give out approximately the same amount of heat but if they look nice and that's what you what want…

My mum has an oil fired system and has no hot water but the heating and the immersion still work. Any ideas?

In the hot water cupboard there will be a motorised diverter valve, this should to be changed. I would recommend a professional to carry out this job.

I'm just about to add a 1.5 bar pump to a currently gravity fed mixer shower. - can you tell me if I have to take a new branch pipe directly from the cold water tank in the loft into the pump, (rather than a branch from the existing pipe coming down that serves the shower and then on to the bath taps), and where should I tap into the hot water pipe coming from the hot tank?

I would recommend that you install a new connection to the cold water storage tank and install a surrey flange to the top of the hot water cylinder, its easy to install and then take your hot water connection from the surrey flange – by doing it this way you comply with all the relevant water bylaws and will NOT invalidate the manufacturers warranty on the pump

I have a Potterton boiler which keeps cutting out because the water pressure is dropping within the sealed system. If I top up the pressure it is fine for a few days. I have noticed that there is a pipe outside which is dripping water probably from the boiler. What could be causing this and how can I fix it?

The pressure relief valve (PRV Valve in trade terms) is leaking – you need a professional. Phone around for quotes; give them the make and model of the boiler. If the problem comes back again a few months later your central heating system will need to be power flushed to remove lime scale, sludge build up and rust. The approx cost £500 plus vat…ouch!

My boiler for the central heating system and water tank heater seems to work fine whilst it is in operation however when the thermostat switches it off when to room is up to temperature there is a large boiling noise and steam comes out of the air eliminator (located upstairs in the airing cupboard next to the pump). We have only been in the house for 10 months so do not know history - but had to replace the central heating pump almost straight away. The system is approx 14 yrs old and the boiler is a baxi, with a flue fan.

I would suggest a professional examines your system, it may need a power flush to remove lime scale, sludge and rust. Over the years the combination of the various metals in the system causes sludge to build up and cause blockages, as the water can't circulate properly the pump usually wears out and pumps over into the expansion tank. Do you have cold spots/patches on your radiators when they are switched on? If so, you need a power flush. The approx cost is £500 plus vat.

We have a new to us (but 3 year old) house, with a gas central heating boiler and thought that when it got hot just lately we could turn of the heating and just leave the hot water on.

Problem is some of the radiators still get hot. The only way we can get cold radiators in some rooms is to turn of the thermostatic valves on the actual radiators. Is this normal?

The motorised valve is faulty, I recommend a professional installs a new one

We have a central heating system that causes us grief. It is a high pressure micro-bore job. There is no tank in the roof, but the tank in the airing cupboard has to be balanced once or twice per year. As far as we know the pump is always on. We have the boiler serviced annually. Is there an idiot's guide to high pressure systems- we don't want to tinker just understand how it works. If we want the whole system checking do we need a plumber (the existing one is OFTEC) or a heating system company and how do we choose one?

I recommend you contact the Institute of plumbing (tel 01708 472791, and obtain three quotes for the overhaul of your system. This is definitely one for a heating engineer or experienced plumber.

We have just had a new combi boiler and radiators installed as well as trv on all bar shunt in bathroom, our gas bill was huge and the guy at BG suggested getting a room thermostat installed to shutdown the boiler rather than allow flow through pipes and one radiator, is this right and will it save money and wear on boiler? Can you recommend a stat?

The BG chap is correct. I would recommend a Danfoss RF1 INFRA RED unit, as its infrared, there are no wires, so it's like having a TV remote that controls the temperature of your radiators (I have this in my home). The approx cost of the unit and installation would be £250 plus vat.

How do I go about installing thermostatic radiator valves and do you put them on all the radiators?

Drain the central heating system by attaching a hose to the drain off point, which is located at the lowest point on the system. Put lots of dust sheets and towels down as the water in this system will be black and WILL stain whatever floor you have.

You will need a spanner and a roll of PTFE Tape. Unscrew and remove the radiator body, you should NOT have to remove the part that fits into the radiator as you can buy compatible radiator valves. Holding the rad valve in your left hand wrap the PTFE tape around the thread of the valve moving away from you, approximately 8 full wraps per valve. Secure the new rad valve to existing pipe and rad connection

The top of my heated towel rail on the second floor (i.e. highest radiator in the house) never gets warm even though I've bled the air out of it. Could it be because the pressure is very low but how do I increase it? There is also a constant dripping from the overflow to the Megaflo Boiler.

Yep the pressure is low and you've identified why! You need a new pressure relief valve on your megaflow. Once fitted, top up the pressure on your system and the towel warmer will be fine.

I'm about to replace my boiler. Are there any good Combi boilers you can recommend, or features I should look out for?

As a business we only install Vaillants (we are independent and have NO ties or connections to Vaillant) however they are the most efficient and reliable, and that's the market I want my company to be associated with. Recently the Energy Savings Trust (an independent Government body) tested all 1090 boilers that are available on the UK market for efficiency, Vaillant had 7 boilers in the top 10.

My Baxi Combi boiler has started leaking around the push rod on the diverter valve assembly, even though the boiler is only 2.5 years old. Is this to be expected or should I complain to Baxi?

It's a very common problem though that's not what Baxi will tell you. Write a letter to the Managing Director outlining your concerns. In future install a German built boiler, much more reliable.

We have new pressurised oil central heating installed 5 months ago. It is running at the recommended 1 bar - how often should it need re-pressurising?

Keep an eye on it every 3 months, if it drops to half a bar you will have a small leak on the system. If that happens check all the radiator valves with a piece of tissue, making sure the heating is off when you do this. It shouldn't drop at all.

What pipe systems do you recommend for central heating, bearing in mind cost and ease of fitting?

A 2 pipe system, flow and return would be best. Install 22mm from the boiler to each room and then reduce down to 15mm approx a meter away from each radiator.

I have a very old boiler which leaks and is also incredibly noisy .Is there any way to repair a leak?

It sounds like you have a very old floor standing conventional boiler – they normally leak on the heat exchanger, if so I'm afraid it's a new boiler.

How do you get an old tank out of a loft?

If it's metal, you will have to cut it up with an angle grinder, if it's plastic you can saw it up until you get it out of the loft hatch.

My Combi boiler has been recently drained and now one of 2 of the radiators does not heat up fully and the hot water does not always come on. I have drained the radiators as best I can (it took ages) but now no more air comes out. The boiler is about 8 yrs old apparently. There weren't any problems before it was drained! Can I do anything??

Turn off all the rads except the 2 you are having a problem with. As the others are turned off the pump inside the boiler will force the water into the radiators in question. Next time add Fernox restorer to one of the radiators, it comes in a mastic type tube and can be squeezed out with a mastic gun, the chemical will clean the inside of the system and offer a measure of protection from sludge…….its really good stuff.

What is ‘kettling' and is it something I can rectify myself?

Kettling is caused by a build up of lime scale and sludge in the central heating system.

The solution depends on what type of system you have, i.e. a combination boiler or a conventional system. If you a have combi, you need to install boiler silencer (both Fernox and Sentinal are excellent products) they come in a mastic type tube and can be installed with a mastic gun. If you have a conventional system, you need a bottle of liquid boiler silencer. Empty some of the water from the central heating releasing water from the drain off point and then pour the chemical into the feed and expansion tank.

The gas board have advised me my system needs to be flushed and are offering to do it for £500. Is it something I could do myself, if not is £500 reasonable?

Yep and I would not advise you attempt this type of job yourself.

Last year we had a condensing combination boiler installed but it takes a number of efforts to fire up. This happens in the morning when the heating is turned on and when we run taps or showers. The plumber who fitted it didn't leave a Gas Safe certificate. Help!

Did the engineer carry out the appropriate tests before he/she installed the boiler? You need to have the appropriate minimum pressure supply to the boiler as specified by your boiler manufacturer. Was the system power flushed prior to the installation of the new combi boiler? If not, which I suspect, dirt from the system may have entered your boiler and caused a partial blockage. Can you get your engineer back? If not, consult the manufacturer.

Our new-build house has radiators fitted with individual thermostats, except the one in the entrance hall, which makes noises as water flows through it. We have tried bleeding every radiator but the noise persists. We have a pressure system, which needs to be re-pressurised about once a week. Any ideas please!

Firstly you have a leak on the system somewhere. Check all the radiator valves when the heating is switched off with a piece of tissue, you'll probably find a small weep. I suspect the noise comes from a thermostatic valve that has been installed on the return pipe of the radiator instead of the flow pipe.

We need to flush our radiator system and need to add some new inhibitor, the inhibitor states that it is for use in an indirect heating system. What is an indirect heating system? Our boiler is a gloworm 24CXI.

As your boiler is a condensing combination boiler, I would recommend Fernox restorer. It comes in mastic type tube and is applied into a radiator from a mastic gun.

At the moment every time my loo flushes, the combi boiler fires up! It is a Vaillant combi that, slowly but surely, loses pressure during the day. I am guessing that there is a leak from the pipe work coming from the boiler - the pipes are under some concrete screed and that is damp.

Before you dig up the concrete floor looking for the leak, I recommend you add Fernox leak sealer to the system; it comes in a mastic type tube and can be added to a radiator, if the leak is small, this should do the trick. If not, you need a company that offers non-destructive leak detection. What we do is use a special camera that can see through into the concrete in the floor (even if there is carpet or tiles) we can normally pinpoint the leak to within 10 inches thus saving time and lots of digging.

Kitchen issues

I'm about to replace my kitchen and need to run some new pipework to the sink. I've replaced a couple of bathroom suites in the past so I kind of know what to expect. However, previously I've always used push-fit connectors instead of compression / soldering. This time I'm thinking of soldering. Is there one form of connection that you would recommend above another? Is my assumption that soldering is the best (i.e. least likely to leak) correct? I'm going to have to channel out a concrete floor to do this so any tips would be more than gratefully received.

I would recommend you use push fit connectors, for example HEP or John Guest fittings – if used correctly they won't let you down.

I've got a dishwasher waiting to be put in place, although I'd need about 4-5 feet of pipework to get it connected. I'm OK at DIY, so is this something I could reasonably do myself with little risk? Or should I leave it to a plumber and, if so, what sort of cost would be reasonable?

Leave it to a plumber as the waste outlets needs to be installed correctly otherwise you could have few blockages in time. The approx is £150 plus vat.

Our electric oven has broken. We want to replace it with an electric oven and a gas hob. I don't know who we should get to install it (since it involves gas). My sister says a plumber. Is that right?

I would recommend an electrician for the oven, and a Gas Safe registered engineer for the Gas Hob.

My kitchen hot tap runs ok until the water gets hot then there is an almighty "clunk" and the flow reduces. Turning the tap open further helps for a while till the same thing happens again. Continuously turning solves the problem but then you have Niagra pressure hot water coming out.

I recommend you change the tap.

We have a mixer tap in the kitchen. At present only cold water is getting through. The hot water supply from the emersion tank is connected, switched on and open on full. Why is the hot water not getting through?

Install a new tap washer or tap cartridge.

I recently bought a De Longhi professional cooker from a friend but I'm having problems getting it connected. I've been told by a relative that the pipe isn't UK standard and so when connecting it to the flexible pipe that leads to the gas outlet, it won't fit.

You need to speak to the manufacturer and confirm that your model is to a UK spec.

I've called a few Gas Safe registered plumbers but they've advised it will cost either £55 per hour (no guarantee it will be fixed within the hour!) or £110 to fit and connect. Do you have any advice or will I just have to pay?

If your engineer can confidently confirm that he can do the whole job for a £110 …bite his arm off….its a deal.

The hot water in the mixer tap in the kitchen only trickles hot water. Is there anything that can be done to cure this?

Install a new cartridge or change the washer.

Water pressure

I have a major problem with the water pressure into the house. The water supply is on a shared mains with several other properties and being the last house on the supply I only get a trickle of water out of the taps at best. Other than being connected to the mains, is there any other way to increase the flow of water?

Consult your water supplier as they have an obligation to give you a minimum water pressure and flow rate.

I am fitting a new electric through-flow shower which needs water pressure to be set between 1.5 and 10 bar. Can I assume that domestic mains pressure will be within this range, if not, how can I check it without a manometer?

Contact your local water authority, they will send out an engineer to test your water pressure and flow rate. Do NOT assume it will be ok.

How do I get a better flow in the upstairs hot water tap? Is the only way to lift the cold water tank to get a better head?

Yes or install a negative head pump.

We have an outside tap running from the kitchen sink but when I turned it on this year the water pressure was much lower. The kitchen taps are fine.

Change the tap.


Our stopcock is hard to reach and very stiff, can you advice on a possible implement to help reach and turn?

Your local plumbing merchant will have the appropriate tool in stock approx £15.

The mains inlet stopcock to my property has a slow leak - it drips out of the tap spindle - I can also turn the water off outside the house at the mains - the stopcock is a brass tap (painted over) - can I take the tap off and stop the leak by changing a washer or part of the tap?

At the top of the spindle is a small brass gland, undo this and wrap PTFE tape around it and then tighten it up. Job done, no more leak.


Certain sinks in the house have cold water for a second then it stops, one toilet doesn't fill very fast and the shower only gives out hot water. Any ideas on what the problem could be?

It sounds like your plumbing system could benefit from a pump; I would obtain 3 quotes from local plumbers.

Our overflow is constantly running from upstairs. The only way to stop it is to run the hot tap then it starts again. How can I stop it?

It would appear you have a pressurised hot water system; you need to change the pressure relief valve. You will need a professional for this job.

Do you have any tips for making sure a solder joint is soldered properly, so a perfect seal is formed?

The only way to test is (1) open up the water and see if it leaks (2) connect up the pipe to an air compressor and test the pipe run to see if it leaks. That's it

I would like to fit a tap outside in my garden. How good are the DIY kits or should I get a plumber to do it properly?

I would advise you get a plumber to do it.

There is a terrible smell when the washing machine starts its cycle. The waster is plumbed into a standard outdoor drain, and said drain does not whiff at all. And after the initial few minutes the smell disappears. Any ideas what could be causing this?

Check the P-Trap (this is the u-bend) where the outlet hose connects to, you may find it partially blocked. If not, you need an appliance engineer.

I'm on a shared supply with 5 houses and Thames Water have issued statutory notices for us to repair the leak within 14 days or they will do it and recover reasonable costs following completion of the work. They are offering to have the leaking supply pipe replaced under Thames Water's discount offer (£150 per property). Should I ignore them, get my own plumber or accept Thames offer?

Accept their offer – it's very good.

Have you got any advice on how to get the best priced materials?

Make a list of all the products you want; fax it to your local and preferred suppliers and ask them for their best prices.

Are macerators any good - would you recommend installing one in lieu (loo!) of the disruption of installing a new soil pipe and foul drain run?

If they are installed according to the manufactures instructions they are great – the golden rule is do not install any 90° bends only 135°bends.

When I put powder in the washing machine dispenser, there is always half of it left behind.

Not a plumbing question sorry, you need an appliance engineer.

I'm just finishing the first year of a 2 year plumbing NVQ/Technical Certificate at night school. The problem I have is all I'm doing at the moment is what I do at college. I really need some practical experience "on the job" but don't know how to get it is I'm not sure I'm confident enough to advertise my services alone and can only do weekends and certain evenings as I work full time at the moment.

Get your local paper and contact local plumbers and offer your services as a keen student willing to learn – I must warn you competition is tough but stick at it.

I want to move my washing machine into the garage, what do I do about drainage?

You need to ensure that the drain is within 4meters

As of Jan 1 2005 New Electrical Regulations came into effect that basically preclude DIY work in Bathrooms unless subsequently a certificate of compliance is obtained. I've recently had a new bathroom "professionally" installed and cannot get the certificate as the Certifying Engineer says that he cannot see any earth bonding of the water pipes/ radiator system. He states that all earth bonding must be visible! This I do not believe as that precludes the fitment of enclosed bath panels and would require a visible bond in the shower cubicle. What I believe he means is that he should have been present when the bonding was applied, i.e. before any closures were installed. Is this right?

Your engineer is correct – I know its madness.

My waste pipe directly under my sink is not screwed in, it was glued in place, are there any adhesives you would recommend that could do the job effectively?

Solvent weld glue would be best.

To use compression fittings with poly pipe do you need to use metal rather than plastic pipe inserts?

You can use either but make sure you wrap the olives with PTFE tape or they will leak.

I want to fit a garden tap but the kit from B&Q only has a 15mm self cutter is it possible to buy a 22 mm self cutter?

Yes, it will have to be specially ordered by your plumbing shop.

I have been led to believe that my drains are so old (over 50 yrs) that I am not technically responsible for them. Something to do with a law being passed after that time?

I would consult your local authority as some bylaws are regional.

My mother appears to have some sort of leak from the loft where the cold water tank is. The wet is coming through the ceiling and down the wall in one of the bedrooms and is worse after flushing either of the 2 toilets. Is there anything she can do herself or will she have to actually call out a plumber?

Call a plumber ASAP.

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