Why does my main burner not start?

I have a Potterton Netaheat Profile 60e and the gas valve does not open but the pilot works and the fan runs. There appears to be a connection problem on the four wire plug and socket under the boiler. By unplugging and replugging it reseats itself and will then open the valve. A niggling problem especially on a cold morning. Any ideas why the connection is bad?

PottPro60e
November 2008

Sounds like a problem with the flame failure device... Depending on what variant of the 10/16 you have; these can be very hard to come-by - If you can get it at all.

I will suggest that the part you need is a mercury vapour ffd which plugs into the end of the gas valve... As the pilot light (Once lit) heats up the phial, it expands a bellow in the ffd unit, which opens the main gas through into the appliance.

GasAid.co.uk
January 2007