Cold Radiators Downstairs

[geoff.51]

Hi, I've had this problem for a while. I have a fully pumped system with 3 way divertor valve. I have hot water and hot radiators upstairs. All radiators downstairs are cold (6 rads). A new pump was fitted, I have flushed the system with Sentinel X800 and X400. Also power flushed system. Recently drained down system again, flushed all radiators and opened all valves which flowed freely with hot on oneside and luke warm on other. Fitted a magnetic Boiler Mag filter, refilled system and still hot radiators upstairs but cold downstairs. If there is a solid plug of magnetite in pipes between upstairs and down stairs, how come the water flows freely from both hot and cold feed, but as soon as radiators refilled no heat?

 

[king of pipes]

Have you tried turning all the radiators that get hot off upstairs ? to see if the pump can move any trapped air in the downstairs rads ? you can even turn all but one of them off and see if any heat comes through then work through one by one till they all get hot, air is a funny thing and often hard to remove especially in a open vented system the pump may need venting ? you can normally hear air traveling through the system at the pump position if this is the case . Kop

 

[geoff.51]

Have you tried turning all the radiators that get hot off upstairs ? to see if the pump can move any trapped air in the downstairs rads ? you can even turn all but one of them off and see if any heat comes through then work through one by one till they all get hot, air is a funny thing and often hard to remove especially in a open vented system the pump may need venting ? you can normally hear air traveling through the system at the pump position if this is the case . Kop

Thanks I’ll give that a try today
[automerge]1572765773[/automerge]
Thanks I’ll give that a try today

 

[Chuck]

Hi, I've had this problem for a while.

Have the downstairs radiators ever worked properly?

 

[geoff.51]

Have the downstairs radiators ever worked properly?

Yes. It’s a Potterton Neta Heat boiler and the whole system worked perfectly until a couple of years ago when I started having problems after summer period when central heating was turned on. Hot water runs all year but during summer when C/H not needed thermostat turn right down. It used to work after leaving C/H running for a few hours as if it cleared itself

 

[moonlight]

Have you checked the thermostatic valves pins are not jammed down? If your down stairs are on drops you might find you have to close the hot ones off upstairs and open each one down stairs in succession and close when hot until they all heat.

 

[geoff.51]

Have you checked the thermostatic valves pins are not jammed down? If your down stairs are on drops you might find you have to close the hot ones off upstairs and open each one down stairs in succession and close when hot until they all heat.

TRVs are all open as tops removed and pins up. Now got upstairs valves shut off. Pump set to full on and boiler turned up to high. Now getting some heat to 2 small radiators downstairs. Leaving it on for as long as possible with hope it will start to clear blockage