by htg engineer »
Fri Oct 03, 2008 9:23 am
What's the pilot like ? should be a strong blue flame.
When the fan is running (heating or water on) does the flame lift away from the thermocouple ?
What does the thermocouple look like ? any soot or white deposits, does it look old/past it.
If the Hot water works when you open a tap, and the central heating works when turned on - then the wax diverter will probably be ok - rule that out.
If the radiators get hot, the boiler is not banging etc then i'd assume the heat-ex is ok - for now. Get the pilot working properly, maybe change the thermocouple (cheapest part to replace).
Does the pump get mad hot ? it will obviously get hot, but sometimes they get too hot to touch, when the happens the impeller will turn for a short while, once it's too hot it will slow andf the boiler will overheat. Easiest way to check, is to remove the pump head (drain down, undo 2/4 bolts securing pump head and visually check impeller.
I'm in the Newcastle area.
htg