potterton he 115 boiler lockout!!

[nicko75]

can anyone help me out.

just moved into a new property with a potterton powermax he 115 condensing boiler fitted. after moving in the boiler kept locking out giving a a07 code(heat exchanger monitering fault) after the lockout. the lockouts weren't that frequent as we were only using hot water through the summer months.

When i came to turn the central heating on the lockouts became more frequent. called the installer back and he said there was nothing wrong as he fired the boiler up no problem. when he left the lockouts carried on, so i called an engineer out from potterton/baxi. He told me the problem was with the flue, as there needed to be more of a fall on it as this was causing the a07 lockouts. when he left no lockouts for 2 weeks until i went into the loft and noticed one of the joints on the flue disconnected. needless to say when i connected it back up, 'lockout city' again.

So I called the installer back and he put more of a fall on the flue pipe, the lockouts have become less frequent but they do still occur.

Can anyone give me any ideas on this one?

 

[a jeffries]

the problem sounds like the ballerfix on the "bypass" has been left wide open, this causes the return temp sensor to get too hot, thus a lock out. easy to fix, locate the bypass ballerfix, and cause it 3/4 of the way this forces the water around your heating system......

 

[nicko75]

cheers for the reply, but still no good probably didn't give enough info on the first post, but it when it locks out its when it first goes to fire up, and when it does fire up it can take about two or three attempts!!

don't know if its just me but it only seems to lock out when its heating up the hot water.

any other ideas?

 

[a jeffries]

it does sound like a strange fault and its hard to say what it is without testing the boiler, but if it only locks out on hot water mode it could be the tank sensor is either faulty or not fully inserted in to the tank, this could cause the return temperature to be too high.