pilot light going out

[daveneedshelp]

help!! i have a ravenheat 820/20t combi boiler, when i turn the hot water tap on the burner fires up as normal and gives hot water as normal, but when i turn the tap off the burner cuts out as normal but 10 seconds or so after the pilot light goes out and the pilot light button pops out then i then try to get the pilot light back on again but it takes ages for the button to stay in and ignite the pilot light.It doesn’t matter how long the hot water has been on, it still cuts out the pilot light, any advise would be appriciated.

 

[mr-crs]

I sounds like the fan is not slow running when boiler is idling does your pilot light go out overnight? remove the cover and inspect the fan it should run slowly with no demand for heat if not check for power at fan if power is present replace fan

 

[geoff@cetltd]

a relay or the fan is CORGI'd

 

[Agile]

The main heat exchanger is scaled up and the latent heat trips the over heat stat a few seconds after the burner goes out.

You have to wait "ages" because the HE has to cool down and there is about 16°C histeresis in the cheap stats.

Tony Glazier

 

[geoff@cetltd]

Yeah - I thought that at first

 

[pierrot]

The main heat exchanger is scaled up and the latent heat trips the over heat stat a few seconds after the burner goes out.

You have to wait "ages" because the HE has to cool down and there is about 16°C histeresis in the cheap stats.

Tony Glazier

Ditto

 

[daveneedshelp]

thanks for sugestions, i have put fernox boiler silencer in the system which has quietened it down, so i'm thinking maybe it might not be the heat exchanger clogged, any other idea's?...i can feel myself having to call out a plumber soon...Damn!!!