Hi so we have an open vented central heating system with 18 rads. All was working fine. We recently chemically cleaned the system, added a magnaclean and flushed through a few rads. The system was drained and refilled a few times. After refilling the final time all rads were bled. However we have one rad that despite having a very hot feed pipe, the rad remains cold. Perhaps slight warmth at the very top but virtually cold. We've tried turning off the other rads to force the water through the cold one but this just causes the boiler to overheat. We've also tried completely balancing the whole system and still nothing. We know there's no sludge in this rad as it was one of the ones flushed and the water in the system itself is pretty clean now. I've tried playing around with the lockshield on the cold rad but nothing makes much difference.
Is there something I'm missing as the rad was previously getting v hot and I'm stumped.
Any help much appreciated.
Is there something I'm missing as the rad was previously getting v hot and I'm stumped.
Any help much appreciated.
