DIY Doctor UK DIY Forums

Our boiler fires up for approx. 5 minutes goes off for 3 and then fires up again, engineer says that the boiler is okay has checked the flow and return and he said the temperature is dropping very quickly. We have one rad at the end of the line that does not heat up completely, it has a warm spot at the bottom, but the top is hot.

That is very probably normal as boilers can cycle quite quickly. If a rad is hot at the bottom and cold at the top means it is full of air so need bleeding.

Poor flow is the opposite - cold bottom hot top.