Header tank overflowing (NOT BALL VALVE)

[keithb]

HI,

I have been having problems with water coming from the header tank overflow. I was advised that it is probably due to a faulty ball valve. I investigated and the old valve looked fine, but i installed a new one anyway.

This did not resolve the problem. The water usually comes from the overflow within 10 mins of turning on the heating.

Something appears to be backing water into the tank. All readiators appear to be heating ok, but i assume there is a problem with the circulation of water.

Please advise what i can check/do.

 

[Gas2Air]

Check if you have one, the open vent for pumping over, signs of pumping over. If you have a combined feed and vent, check the level doesn't rise when the heating is on.

How old is the system, is the pump old?

Could be a split cylinder coil, is it an indirect, direct, mains fed cylinder? What position is the header tank in relation to the domestic tank?

Have fun.