No Hot water and Downstairs radiators not heating

6 Nov 2006
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United Kingdom
I have a pumped system with two 2-port motorised valves.

The copper tank was not heating up the cold water so the copper tank/hot motorised valve was changed since this seemed suspect. To change the motorised valve I drained the central heating system but now I can't get the downstairs radiators to warm-up. They have been bled and filled-up.

Also, I still get no hot water only luke warm. The bolier pipes (central heating) pipes entering the copper tank are very HOT so hot water is going into the tank.

Could there be limescale inside the tank? On the coil?

Why are the upstair radiators only warm? Air lock?

Weak pump causing both symptoms?
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Try bleeding the pump first.

Are both zone valves opening when you call for heat :?:
The heating is OK now. I reckon the central heating system has settled now but the copper tank is not heating up the water.

Yes - both motorised valves are working as they should.
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Slow downstairs rads, is often due to sludge. Sludge wears out pumps, sometimes very quickly. So perhaps the pump would be a suspect.

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