Central heating problems - any plumers out there?

    Hi, I was just wondering/hoping that someone might be able to give me some advice on my currently not working central heating. Its only 5 years old but stopped working yesterday.

    It is switched on, the thermostat is still clicking when it gets to the temp (it only does this when CH is on) and the boiler is still firing but system is still cold. Over the last few weeks I've noticed that the pump has been rattling a lot so wonder if this could be the problem.

    Does anyone have any ideas on what problem might be and likely cost to sort out? I'm not doing this for a 100% accurate diagnosis or cost, its just that I don't have any ideas as to cost/problem so would just like to have some ideas when I call a plumer.



    I am not a plumer but i have done a bit of boulding and tylin.........can you reach the should be able to feel it running......when first starting one pipe will be hot and one cooler,but gets hot very quick if the pump is is not hard to change the pump if you have isolating valves either side of the pump (a screwdriver slot on the joint above and below the pump) of luck.

    A fair charge to supply and change the pump would be around £100 and should take 30 minutes...........but...first find a decent plumber....and DO NOT USE YELLOW PAGES.....but phone a friend

    I take it that you have a seperate boiler for your heating, and an immersion heater for your hot water?

    If you get hot water and central heating from the boiler do you now get 1,2 or both........turn the central heating right down by the room stat and turn the hot water stat right down.........the boiler should stop firing......turn the room stat right up,the boiler should fire,....ok......turn the room stat right down again,the boiler should cut do the same process with the hot water stat.........does the boiler fire up for hot water.........try this and get back to us.....

    If the pump is not working as it should the boiler will cut out very quickly as the water temp (as it is not circulating quickly) will cause the boiler to overheat and the internal stat will shut the boiler down

    Original Poster

    Thanks for all replies. In answer to questions, the water is heated by immersion so boiler just does CH. The pump is not doing anything at all no vibration or racket is usually makes and the pipe on one side was red hot but other side was cold. The boiler is only coming on for a little while at a time, or was until I turned CH off.

    Think I might take a look at doing it myself and do what most 20 somethings do when faced with any problems like this - phone my dad. :roll:

    It's not a hard job.

    The hardest thing is isolating the water.

    Original Poster

    I hope not, although I think I'll need to get my dad round just to reassure my wife. If I tell her once more that something is just a little job and I should have no problems then I'll think CH will be least of my problems.:-D

    On a serious note thanks to both of you, rep left for help.

    Might be on later asking for advice on sorting out a flooded house and irate wife.:w00t:


    I just had exactly the same thing happen on my 3 year old system. The pumps used these days are only designed to work for 5 years. So looks like you have got your moneys worth from it.

    It cost me £120 but this included a system check and a bag of sweets for my two buys (the plumber is a friend of the family). It took about an hour all together, but most of that was chatting.

    Its an easy job to replace the pump, next time I will try this myself first.

    It is a very easy job if you have a gate valve either side of the pump. Switch of electrics and undo the connection. If there is a valve either side simply close both of the vavles and undo the nuts holding on the pump. Buy one the same size and refit the new one. You might have to prime the pump with water but the instructions that come with the pump tell you how to do this.

    Have a look on the…mps and see if you can spot a pump that looks like yours.....

    Unless you have an enormous house should be about £40 for a pump.

    (Before replacing the pump you should check that the pump is receiving power in could be a circuit fault but its more likely to be the pump)

    A tip I read somewhere was to run your heating for a few mins in the summer every couple weeks otherwise the sediment collects in the pump and come autumn when you switch on it fries....

    Original Poster

    Thanks Ultimo and Gari. I had a look at it again this afternoon and after reading a few websites took the (serious) advice of hitting it gently with a hammer. Lo and behold it started working again, although a bit loud.

    There are valves either side so I'm going to take it out and as luck would have it my dad has an unused one in his garage, so I'm going to fix that.

    I don't know why he had it! Maybe I'll find out when I'm his age and have random stuff in my garage?

    Original Poster

    Just realised what a plum I am. Can't believe I managed to misspell the title!

    Pumps can be affected by scale (just like fish tank ones). Make sure you ise a decent cleaner to keep the scale down in future. A water softner would also do the trick, or maybe even one of those magnetic ones. This cleaner is the best (IMO)…0ml
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