Recent content by wurmstrangler

Problem solved. Massive amounts of air in the system because the header tank in the loft was empty. The ballcock inlet valve was jammed shut with limescale. Thanks for your help.

Thanks dilalio. It's Y plan. The pump can't be the problem because it runs perfectly without noise if it's just heating the rads. I can't see how the MCV could affect it. I'm guessing air or sludge in the HW loop of the pipework, but given that it's a vented system, I can't see where air could...

My Central Heating pump is very noisy BUT ONLY when heating the hot water cylinder. When just heating the radiators it runs silently (as it should). If heating both the hot water and the radiators, it is noisy. Any ideas?