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Discuss Central heating and pipework issus all over newly bought house. in the Plumbing Forum area at

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  1. KevRusski

    KevRusski New Member


    I am looking for advice from the skilled and knowledgeable as it seems very hard to pin down a plumber to look at all the issues I have without several call outs and costs.

    I bought a house about 6 months ago (30year old) and got straight on with some renovations. As part of this process we had 4 radiators off the walls in order to decorate and plaster around them.

    This was summer time so we had not tested the heating to know if any of the current issues were there before. The only issue we had noticed here the awful sound of waste water constantly making a drip sound in the internal SVP and a tap tap tap noise every time we put on the hot water tap.

    I think the only way to rectify the SVP is have it re-routed and the tapping noise is to locate where this is occurring and either move the pipe away from the wood local to it or put some pipe insulation around it at the point it is tapping/expanding. Sensible?

    Now onto the main issues. After a couple of weeks after having the central heating on the pipes in the loft started making a really loud clanking noise, like someone was hammering them with a large spanner, and you could hear them jolting about and banging. A couple more weeks passed and the boiler started making some louder running noises when first starting up. At first I genuinely thought it was a helicopter in the sky! It certainly wakes me up. You here the pipes violently rattle in the loft first then about 10 minutes later the boiler. Its like the fan on the boiler is going into overdrive, so much that it must send a vibration though the house and together with the noise creates the sound I hear. This can last up to 30mintes from start up and it accelerates then slows down on about a 10 second cycle.

    We did have an engineer out (because one time the boiler locked out) and he didn't know why this was doing it. However, after re-setting the boiler and it not coming on he discovered that the pump in the airing cupboard was not working, he gave it a few taps and unscrewed it at the front, upon reattaching that screw/valve it kicked back in. From this he deduced it maybe poor flow that is causing the pipes in the loft to rattle and boiler over compensating to disperse the heat until the pump gets going. In other words, the pumps on its way out. On the occasion the boiler tripped the pump may have failed. For info the heating went off late on the evening hours after running normally.

    Other info:

    My radiators have been bled, despite me still hearing some gurgling from one of them (that radiator works fine and wont bleed anymore), I have two radiators which get a lot hotter at the top and both of those seem to take a long time to heat up (an hour).

    I also have a loud tapping to my bedroom radiator when it initially comes on, I think again this is from the feed pipe so probably the pipe expanding against the wood under the floor.

    When removing the radiators previously the water in them was black near the end of emptying them.

    I did wonder if air had got into the system or their was a sludge problem.

    On a separate issue I seem to barely have enough hot water to fill the bath before the water pressure dissapears to zero? Is this an undersized cylinder?

    What I maybe need is a plumber down for the day on day rate to just spend a day sorting it, otherwise this lot could cost me a fortune.
    I did agree with the plumber to replace he pump but Sadly I never heard from him again....

    I was thinking of changing the pump myself as it looks like all I need to do is turn the valves above and below, unscrew, unwire then the same in reverse with the new pump.

    I also feel like the whole system needs flushing?

    Its a standard boiler, British gas 330 , Water tank in the loft, airing cupboard with a water cylinder and their is a magna clean fitted (I am going to clean this tonight).

    Any advice? Possible problem identification /solutions. I was thinking of jumping to a combi in a few years so I didn't want to waste too much money on sorting issues that become de-funct issues. I obviously cant live with this as it is though.
    Last edited: Jan 9, 2017
  2. rpm

    rpm Trusted Plumber

    Welcome to the forum Kev, try and add a link from this post to the sub section in the link below.

    [DLMURL=""]I'm looking for a Plumber or Gas Engineer[/DLMURL]
    • Like Like x 1
  3. KevRusski

    KevRusski New Member

    Sorry, can a mod move this into CH section, and apologise for some grammar, when typing it is not inputting some of my presses!
  4. rpm

    rpm Trusted Plumber

    I`m sure one of them will attend to it later on today after they finish working.
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  5. jtsplumbing

    jtsplumbing Plumber GSR Top Contributor!!

    How meny radiators on system ? unfortunley it sounds like you will have to spend a fair amount to get your system sorted, possibly to most expensive will be the power flush , do you have any figures in mind as to what it may cost ?? or what you want to spend ?
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  6. KevRusski

    KevRusski New Member

    What makes you give that assumption?
    If the last plumber was right, perhaps I just need a new pump in the airing cupboard, perhaps this resolves the banging pipes and boiler ramping up and down which are the two main issues.

    I'm not sure if Plumbers do jobs on a day basis but how much would a plumber expect to be paid for a days labour + material costs?

    I`m making a stab in the dark regarding flushing the system etc but just putting it out there....

    12 rads.
  7. rpm

    rpm Trusted Plumber

    Hi, what size of pipe goes to the rads? Small bore pipes cause hassle with sludge and can cause the pump to work overtime trying to move the water through the system. Powerflushing these can also be a pain. Might be better to make that jump earlier than expected rather than waste time and money now.
    Last edited: Jan 9, 2017
  8. Best

    Best Trusted Plumber Top Contributor!!

    You obviously wish to save money and you could try flushing your system yourself, using chemical cleaner into system for whatever period of time it has to work. Rads taken off should have been flushed thoroughly using a garden hose.
    Does your system have any pressure relief valves that could be hammering open and closed?
    Your soil pipe needs to be not tight to plasterboard or timber
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  9. Best

    Best Trusted Plumber Top Contributor!!

    We don't speak of pricing as it can vary from each region and also particular job. Better to get someone to look at job and give advice and costs.
    But remember you have the plumbers wages and business costs together.
    What sort of overall daily cost were you thinking is reasonable?
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    Last edited: Jan 9, 2017
  10. rpm

    rpm Trusted Plumber

    Just a stab in the dark ...
    Could the noise in the SVP be from a faulty toilet cistern ie internal overflow or dump valve leaking water in to the pan?
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  11. jtsplumbing

    jtsplumbing Plumber GSR Top Contributor!!

    If as you suspect , you have sludge in the system just replacing the pump wont make any difference,
    Costs for a plumber for the day, Depends on Location ! if he's going to be touching boiler then you will need a Gas Safe registered one so you will be in the £150 to £300 per day bracket, can-not comment on materials as don't know what will be required. Power flush 12 rads Around £600 +.
  12. KevRusski

    KevRusski New Member

    thanks for feedback so far, from all I was prepared for cost s of around £500 for pump replacement and flushed/rads rebalanced.

    I will investigate some of the other comments as I'm not up on the terminology, pretty sure the SVP is really tight fit as it passes through the ceiling into the loft, it's not the cistern.

    The pipes are not small bore, these look a standard traditional size. In my last house they were small bore.
  13. Best

    Best Trusted Plumber Top Contributor!!

    You need cost of new pump, plus decent chemicals for cleaning system plus inhibitor to finally put into system to help prevent further corrosion.
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  14. king of pipes

    king of pipes Trusted Plumber GSR

    As above bud chemically clean the system sentinel x 400 leave in the system and run it as normal to break up sludge and magnatite up to 2 weeks then drain the system while hot and flush change the pump at this stage refill and add sentinel x 100 inhibitor vent the system and fire up the boiler you should see a improvement, knocking and banging pipework is normally due to pipes being installed poorly take the floorboards up have a look ease notches in joists wrap hair felt lagging where pipes can expand and rub , screw the floorboards down
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  15. KevRusski

    KevRusski New Member

    Thanks guys, I cleaned off all the sludge from the magna clean last night, rebalanced my radiators and I seem to be getting all rads on at high temp. Quite a few of the rads are not as hot at the bottom as they are at the top, maybe by 20% difference in temp.

    Last night I had no knocking in the loft, all the usual creaking/tapping when the heat up (but that can be dealt with later). However, the Boiler was still cycling up and down as if it was struggling to keep temp down.

    Can I ask, if it was the pump not performing or on its way out wouldn't you be able to hear the pumps speed vary too? Its just the pump sounds fine and I would have thought you would be able to hear that struggling in tandom with the boiler (if it was the ch pump)?
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