We had a new radiator fitted in the bedroom a few months back and it won't warm up at all - it's stone cold. We've only just noticed this because up until this week we hadn't used the radiators since the summer. All the other radiators in the house are fine. The central heating system is over 20 years old and so the new radiator is different to the old ones, it also has a thermostatic valve whereas the other radiators don't. We've tried bleeding the new radiator but it's made no difference. We can't get the valve to turn either, so we don't know if it's open or closed.
