Vertical Radiator Issues

[Chrisscotty]

Hi,

I've just had my central heating pump changed and ever since my 10 bar vertical rad hasn't been working correctly. It has worked fine in the past. I'm confident it is bled correctly and doesn't have any air.

It's seems to get hot at the top half and also the first 2 bars from the flow side are cold. Could it be the new pump is forcing water too quickly? Any other ideas?

Thanks in advance.

 

[terryplumb]

Is pump on a gravity fed central heating system , f + e tank in the loft ? Have any lockshield valves been adjusted on any radiators ? Does pump have variable speed settings ?

 

[Chrisscotty]

Hi,

Yes f&e on loft.

Pump does have variable speed. Currently set on 2. Old pump (same pump - grundfos 15-60) was on 3.

Yes other lockshields were changed. Plumber said he 'balanced the system' which I think consisted of randomly turning some lockshields.

 

[terryplumb]

You should ask your plumber to come take a look ,probably just needs the balancing tweeking a bit so the problem rad gets its fair share of the flow ,as I think it isn't .

 

[Chrisscotty]

Thanks.

I have now tried turning off the other rads to temporarily increase the flow the rad. It hasn't really made a difference.

The flow and return pipes are both scalding hot but the rad won't heat up properly.

 

[HERTS P&D]

Is the rad piped up the correct way around?

Andy

 

[Chrisscotty]

I can only assume it is. As it has worked fine for the almost 2 years until it was installed up until the new pump was fitted

I don't know if this makes any odds but the system was drained from the valve on this radiator

 

[HERTS P&D]

You might need to remove the rad and flush it with a hose pipe in the garden.

Andy

 

[Chrisscotty]

Ok thanks. I'll give it a go

 

[terryplumb]

Before you do that ,try closing down ,to almost off ,say 1/4 turn open , the valve on the RETURN side of the problem rad. Leave all other rads off by their TRV valves ( don't touch their lockshield ) and see if it makes any difference.

 

[Chrisscotty]

Hi just to update. All seems sorted now. Gave it another go with all the other rads off and return valve a bit closed and upped the speed of the pump. Heard a rushing sound and all seems fine now. Thanks for your help guys!