Valiant Combi boiler

[bdonnelly]

Hi, I have a Valiant 242EH combi boiler which is about 12 years old. Until recently it has been losing pressure, I have to top the tank up every other day. I have checked as far as reasonable practicable the pipes under the floor and have been unable to detect a leak.
I have checked the radiator valves and there is no sign of a leak there either, also there is no air getting into the system (none comming out of rad. when bleeding after topping up) I have tried Furnox pipe sealer but that has not worked either. Any help or advice will be much appreciated.

 

[Rob]

Look at the pipe which sticks outside from the boiler. Also if your pressure gets to 3bar when hot check the FAQ on expansion vessel problems.

 

[uknokianut]

A friend of mine had the same problem and was topping up system every other day. I told him he must have a visable leak somewhere. After weeks of him searching under floors and all the pipework and the pressure relief outlet pipe, I came to look and took off the inner boiler casing and found the heat exchanger leaking quite badly, but as it was firing, the water was evaporating just as quick, so the leak wasnt visable or dripping from the boiler.

 

[bdonnelly]

Thanks "uknokianut" that sounds possible to me I will have it checked out soon and let you know if it was that.

There is no signs of water from the overflow pipe outside however I will monitor the pressure gauge more closely tomorrow.

Thankyou both for your advice, it really is appreciated!

 

[Agile]

Before you go opening the combustion chamber which is NOT advised for anon CORGI, have you closely inspected the AAV just behind the pump ???

Tony

 

[bdonnelly]

Hi Tony,
I do not intend to fix the problem myself as I am not CORGI registered however any advice given I will inform the Gas board who maintain & service my boiler. I accept we are all human and when somebody checks the boiler they may not notice where the fault may be and then they tell me it must be coming from the pipe work - which is like looking for a needle in a haystack!
I value and appreciate all suggestions given as I know nothing about boilers & central heating systems,
ps I have checked the pipework and it is all as new

 

[cowley]

Agile i think you will find that the AAV on this model is at the top right hand side.