combi fires up when cold water tap used!!! Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[joseph76]

Hi, my combi bioler (vailiant ectec plus)sometimes makes a noise when i used the COLD tap. the its sounds like its firing up??? ie the same noise as when the hot water tap is opened up.

any ideas

in advance thanks

[htg engineer]

Sometimes just the flow of water through the cold water pipes is enough to push the diaphragm and operate the microswitch.

Will the flow of water pass the boiler before getting to the cold tap you're talking about

htg

[Steve the gas]

Hi Joseph,

Can you confirm that it does fire up? :shock:

Steve

[htg engineer]

Also some mixer taps and even washing machines can cause this problem, if the cold water is travelling back up the hot pipe.

Can be solved by fitting NRV's.


htg

[joseph76]

[quote="Steve the gas"]Hi Joseph,

Can you confirm that it does fire up? :shock:

Steve[/quote]

Hi Steve,

I have downloaded the boiler instructions. it looks like it's just the pump which is operating, as this symbol lights up after operating the cold water supply. the gas light only comes on when opening up a hot water tap. so sorry i was mistaking the pump sound for the boiler firing up... doh! i take it this is normal for the pump to operate after using cold water????

[joseph76]

[quote="Steve the gas"]Hi Joseph,

Can you confirm that it does fire up? :shock:

Steve[/quote]

Hi Steve,

I have downloaded the boiler instructions. it looks like it's just the pump which is operating, as this symbol lights up after operating the cold water supply. the gas light only comes on when opening up a hot water tap. so sorry i was mistaking the pump sound for the boiler firing up... doh! i take it this is normal for the pump to operate after using cold water????