I've drained the system to replace radiator in bathrrom. Refilled and repressurised system once job done. Air out of all radiators. Hot water ok. Radiators heat up ok, but noise coming from boiler unit. Air lock somewhere? What is wromg and how do I put it right?

Mike Batson, April 2008

sounds like you may have air trapped in the heat exchanger, I know the ecotec plus range has a filling cycle and an air purge cycle you are supposed to run before running the boiler, assume there is the same on this range (but not sure)

Be careful, if you overheat the heat exchanger in these boilers and blow the HE thermal fuse, you will have to replace the heat exchanger!

T, April 2008