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Central Heating

Radiator flushing

I have an 11 yr old Bosch junior Worcester combi boiler that is only part heating the radiators. We have hot water only when the radiators are not on.we have been told there was nothing wrong with our boiler but the radiators are needing flushing out as it is blocking the he right.he tried bleeding the radiators but there's hardly any air coming out.

2 Answers from MyBuilder Heating Engineers

Best Answer

One can only guess what the problem is or who informed your that the boiler is Ok.Have you check the pressure in the boiler don't only rely on the pressure gauge They can get stuck in a position indicating water pressure is ok.First step increase pressure to 2.5bar. From the lowest level vent rads.etc
This pressure should produce air first and then water.In my experience its very unlikely that your system is blocked by sludge and requires flushing.This flushing method is used when a simple balancing of the system is all that is require


Answered 9th Sep 2015

I agree with DB about the pressure test. Another thing to do is close one valve on each radiator apart from one. If that radiator gets hotter all over than it did before then you know the valves are not blocked and neither is the radiator. Do this on each one. If there are cold spots it may need new valves and/or flushing.
If all radiators get hot one by one then it could potentially be that the pump is no longer producing enough pressure to circulate the water sufficiently. This is just a possibility as there are several potential reasons for the poor circulation, including air locks. If you don't trust the first diagnosis I would suggest calling someone else out. At least you are now armed with a few extra bits of information!


Answered 14th Sep 2015

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