Combi boiler fires up when drawing cold water

[polo1]

Hi guys, second heating enquiry in a few days - sorry!. Doing some electrical work for a customer yesterday. She asks the above question, and I don't have a clue. When she runs any cold tap the boiler can be heard firing up. Sorry, I didn't notice the make of the boiler. As per an earlier post, I'll tell her to get a GS engineer involved unless it's an uncomplicated fix.Regards

 

[R1CKY]

Quite common on Ferroli Modenas, the flow switch inside the boiler, which is supposed to sense water running through the boiler, often detects the surge of pressure which occurs when a cold tap closes suddlenly, washing machines running can also trigger them.

Fitting a non-return valve to the hot outlet from the boiler usually remedies it.

 

[SafeGasInstall]

you need a mini exv vessel , or cold water supply is been teed to close to boiler , but mini rester will solve this problem

 

[polo1]

Thanks for the prompt replies lads (why you not sitting out enjoying the sun???) - I'll tell her to get a GS engineer in. Regards.