Boiler overheating, radiators cold Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[FEELINGCOLD]

My Glow Worm fanned flue condensing boiler has worked perfectly for 13 years. Since switching on regularly in October for winter only the 3 rads closest to the boiler get hot - the other 5 are cold. The feed and return pipes up to a couple of meters of the boiler get boiling hot consequently the boiler overheats and switches off within seconds. Have tested the pump and power flushed the whole system. Would it be worth replacing the heat exchanger - a rather expensive experiment or does anyone have any other ideas? All suggestions welcome thank you.

[The Heating Doctor]

Why do you think change the heat exchanger? If the exchanger was finished there would be leaks. Sounds more like the boiler control stat/ control thermister has ceased to work and boiler now being controled on high limit stat. when was boiler last serviced?

[FEELINGCOLD]

Boiler serviced last October. Had similar symptoms with previous boiler-turned out to be problem with heat exchanger so thought it could be a possibility but agree sounds unlikely now. Many thanks for suggestion - will get engineer to look at it I think.