If anyone can volunteer even a clue as to what is the problem it would be much appreciated. For the past month have had problems with a '97 combi boiler from Vaillant, we're covered for call-outs and parts thank god but no one seems to get to the bottom of the problem. It stopped turning on for hot water a month ago and was losing pressure before it conked out one day - so a new microswitch was put in. That didn't solve the problem so next visit a new diverter valve was put in but after 3 weeks stopped working again - it was sticking then one day the hot water didn't come on. The last engineer changed the diverter valve again (saying that sometimes the parts are faulty), the pressure relief value was changed and a part on the filling loop as the lever arm was loose so he felt that might have caused it to lose pressure before it stopped working. Hot water worked fine and it was turning off and on okay - left it at 1.5 on the bar. Next day the pressure had dropped so called them back told to pressurize it and if it keeps dropping they'll come back. It is still slowly dropping and this is without using the radiators! So after 5 (count 'em) visits by the vaillant engineers the pressure is now slowing dropping but the hot water is working okay, it is coming on straight away and isn't sticking. There is no leak outside - dry as a bone but I read somewhere that the leak can be so small that it can evaporate. Before I hit redial can anyone suggest what I might tell the guy to look for and I'll let you know the outcome.
Vaillant turbo 242 - pressure dropping
- Thread starter Maine
- Start date
As I understand it, a reduction of pressure can only be related to a leak which could be anywhere on the central heating side.or the boiler
The bigger the leak the quicker you lose the pressure
Obviously opening a hot water tap does not affect the pressure.
It will only evaparate quickly due to heat, you need to examine the system while cold.
The pressure relief valve will have a valve seat that could not be fully sealed.
Likewise at the filling loop there is a non return valve that may not be sealing fully. I take it the filling loop has been detached after pressurising.
I wonder if it's possible to have a internal leak?
However,I don't see any other cause than a leak
The bigger the leak the quicker you lose the pressure
Obviously opening a hot water tap does not affect the pressure.
It will only evaparate quickly due to heat, you need to examine the system while cold.
The pressure relief valve will have a valve seat that could not be fully sealed.
Likewise at the filling loop there is a non return valve that may not be sealing fully. I take it the filling loop has been detached after pressurising.
I wonder if it's possible to have a internal leak?
However,I don't see any other cause than a leak
I don't think it matters too much now Phil, It's a long long time ago.
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