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Central Heating

Air in top-most bath towel radiator

Anonymous user 15/03/2024 - 2.44 PM

My central heating system (all radiators and pipes) was replaced 3 months ago. The boiler (still in warranty) is not. Pretty soon after work has finished, I noticed air build up in the top most radiator (a bath towel rail), where the top-most part of the towel radiator is only luke warm. On each occasion, the radiator heats up fully after bleeding it, but I am having to do it every other day. The builder says it could take a few months for the air to settle. Is that right/normal? I could not see any obvious signs of leaks around the radiator valves/boilers, and the system was drained and filled with an inhibitor. There is a permanent connection from the water mains to the boiler (to re-fill) by pulling a lever to open up the water at the bottom of the boiler. The heating pipes themselves are 22mm plastic pipes.

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3 Answers

Anonymous user

Hi, Air is getting into your system, specifically your tail rail as it is most likely the highest point on your system... the only way for air to get into you system is by a gap/hole on your pipework/system which is allowing the atmospheric pressure to push air in. basically you have a leak. PS there is no such thing as letting the system settle for 2 months, once the system has been purged of air.. that is it, done. not more venting. also... why you have a cold main directly installed to fill your heating system is beyond me, you should have a filling loop with a non-return check valve (2 black turn leavers) in a nut shell, you have a leak and hes given you the 2 month excuse so he can not deal with the headache and you shouldn't get builders to install central heating systems, you end up with plastic pipe everywhere and non stop issues in the future. hope this helps, good luck

Answered8 January 2019

Boiler Homecare

Rating: 5 out of 5

Honiton

You have a 'sealed/pressurised' heating system hence the filling valve you mentioned in your post, it is not always possible to vent every air pocket within your heating system after commissioning so expect air to rise to the highest point which appears to be your towel radiator. Air normally cannot enter your type of system so persist with manually bleeding radiators in particular the towel radiator, how ever 3 months from installation seems a long time for there still to be the presence of air pockets in the heating circuit, do you have under floor heating (UFH) as well? As this type of system requires special attention in terms of purging any air from the heating circuits! In addition inside sealed/pressurised boilers are fitted with auto air vents (AAV) they sometimes may fail resulting in air ingress this may be the cause also if there is one fitted to a UFH circuit manifold too if applicable!

Answered8 January 2019

JB Plumbing & Heating

Rating: 5 out of 5

Corby

bleeding a sealed system will remove the majority of the air but there will still be a small amount left. This will generally find its way to the highest parts of the system. Look in to a gene vent this will automatically expel the air. But if the problem persists then speak to the installers.

Answered8 January 2019