Hi, I think this issue has been covered before but my question has still not been answered so any help is greatly appreciated. My sister has a combi system with 4 rads and a towel rail. When the heating comes on all rads heat up, after an hour one radiator in the front room cools and eventually goes cold. There is no TRV on this rad. I have bled all radiators and rebalanced the system with no joy. Any ideas would be great Thanks.
