Ask a tradesperson


Valiant boiler- in summer mode but radiators heat up

Hi, I have set the boiler control to Summer Mode, but sometimes the radiators are heating up. Also set the temperature to zero on the boiler. Does anyone have any advice please?

2 Answers from MyBuilder Plumbers

Best Answer

Common problem in Vaillants. Internal diverter valve not closing properly, especially when hot water plate heat exchanger is partially clogged up. In worst case need both replaced. Around £200 in parts.


Answered 3rd Aug 2021

Sounds like your diverter valve is stuck and allowing hot water to seep into the ch circuit...


Answered 13th Aug 2021

Post your job to find high quality tradespeople and get free quotes

Can’t find an answer? Ask a new question

Question Categories