Hello, in my TA 20/30 the pilot goes out when the main flame is switched off by the thermostat. I have replaced the thermocouple and brushed the quite rusty pilot thingy but it didn't help. I noticed, cleaning (the slightly sooty) thermocouple with a brush wire helps for a day or so but then it misbehaves again :-(( The entire heating system was professionally flushed a hear ago. Please advise.

Groveman, December 2014

On my boiler the pilot goes out when the main burner gets shut down and comes on again when there's a call for heat.

If your boiler makes hot water to your requirements then there's no need to worry about the behaviour of the pilot flame.

I am not qualified to offer specialist advice about boilers...

Good luck..., December 2014