Baxi Combi 105e DHW fine CH not so good

[st10gas]

Hi all, looking for a bit of advice. I'm GSR, been repairing the above boiler for a few weeks. Problem after problem. So far I have replaced the diverter valve, APS, Pressure gauge and PCB.
DHW great, CH comes on runs for approx five minutes then cuts out. Rads get aired but that's it. Was thinking CH sensor. Any other ideas? Ta

 

[ianmcd]

you should sign up for the combustion chamber and you will get all the advice you need , I have no doubt that you are GSR but we are not allowed to give advice on an open forum in case someone reads it and copies it thinking it will fix their problem

 

[James1991]

Check the gauze filter in the return isolator.
Also, as above.