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Brian, Plumber
Category: UK Plumbing
Satisfied Customers: 845
Experience:  16 yrs. experience as plumber, including full bathroom and kitchen installations.
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I have a gloworm 35ci.the ch temp steadily rises to the

Customer Question

Hi I have a gloworm 35ci.the ch temp steadily rises to the point where the boiler rumbles and then cuts out f14. The temp then lowers and shows f5.we have recently added extra rads.I have bled the system totally and replaced the overheat stay as I initially missed the f14 code and only caught the f5.I have noticed the flow is significantly hotter than the return and the pump is excessively hot.the pump runs ok.could the heat exchanger and pipework be the more likely cause?
Submitted: 1 year ago.
Category: UK Plumbing
Expert:  Brian replied 1 year ago.

Yes it could be the heat exchanger but I am presuming the relevance of you stating you added more radiators meant that it worked fine before.

Which immediately points to an airlock in the boiler or primary circuit.

did the auto air vent in the boiler definitely work .

Customer: replied 1 year ago.
I have since taken out the vent screw all together and bled each radiator.the boiler stayed on although at a lower set temp.what is the relevance of the flow and return temps and hot pump.i thought maybe it was running against a blockage or reduced flow through the pipes due to build up.i have bought cleaner and inhibitor and plan to flush system tomorrow
Expert:  Brian replied 1 year ago.

Hi did the system work before you added new radiators if so, as i said before its more likely to be an airlock