Posting again as the responses to my previous boiler issue were very helpful. I've had a new expansion vessel fitted, boiler pressure has been stable. Had a mini service from British Gas since then, when signed up to Homecare, that found no issues . However, when putting on the central heating now 3 radiators are staying stone cold . 5 are boiling hot. Have checked the obvious things like the thermostatic valves are open. Puzzled as to why just 3 . Is there any thing else I can try before I call them out again?