Boiler loosing pressure

[tgm1974]

Hi

Every other day I have to re-fill my boiler to the correct pressure gauge. This has only recently happened and we have checked everywhere for leaks but cant find anything. We have even checked "some pipe" outside the house and this is not leaking either.

Any ideas why this could be happening before we call for a boiler man and pay over the odds!

[The Builder]

If there are no obvious leaks..............then a common cause is a failed diaphragm inside the boiler............... send for Boilerman.................but do get a reccommendation..:o)

[Hymie]

It may be that you have a small leak within the boiler (possibly the heat exchanger), the boiler�s use at this time of year being enough to evapourate the water from the leak. The loss of half a litre of water is sufficient to cause a significant pressure loss within the central heating system.

If you are loosing water within the boiler, once its usage is reduced, you are likely to see drips from the boiler (or wherever the water can escape).

[scorpious123]

have you cheaked your pressure relief valve that could be lifting without you knowing place a bucket at the end of the pipe there and see if it gets any water in bucket over night

[gucciman]

could be a leak on the pipework, most typically around a valve, if your losing water everyday then you would almost certainly see a wet patch somewhere, go around all the radiators and look and feel for wetness.
you can also leave some newspaper below the boiler and see if it catches any water dripping from the boiler.
my money would be on your expansion vessel being flat and needing repressurising. tie a plastic bag over the end of the pipe that you found outside and see if it collects any water.

[Disco Fever]

If you have a normal 2 up 2 down house check under the ground floor floor boards as the leak could be under a part of the house you cannot see....