new 3 port mid pos valve but no heat downstairs

[proplumb]

just replaced mid pos 3 port valve in a rented house for my mate who owns it. Had to re-wire the complete system as it was so out of date but although the new valve etc works, the rads downstairs dont come on at all. Rads upstairs are fine and flow and return at boiler are normal. I didnt have the floor boards up as it was mates rates so wanted to get away after a few hours of sorting out v bad wiring. The tennant reckons the rads worked before but when I went to bleed them no air was present and the water was clean whereas upstairs the rads needed bleeding and water was dirty. Any ideas?

 

[helpsy]

Try shutting the valves down on the rads that are ok and let pump work on problem rads probably airlock which will probably clear with other rads shut down(only select CH also)

 

[REDSAW]

ballancing,
ones beeing a greedy buggga somewhere as helpsy points out.

 

[proplumb]

Ive got to go back to sort out the toilet so will have more time to give your ideas a go. If no joy I think a powerflush is in order. Thanks.

 

[wnjswozo]

Try back filling it ,make sure 3port valve,is manually open when filling

 

[stevetheplumber]

Ive got to go back to sort out the toilet so will have more time to give your ideas a go. If no joy I think a powerflush is in order. Thanks.

if it worked before why would you powerflush it ?

 

[proplumb]

I didn't say it worked before. My mate bought the property to let out and couldn't get the heating to work properly.

 

[jpm]

I didn't say it worked before. My mate bought the property to let out and couldn't get the heating to work properly.

why change the valve then?

 

[helpsy]

If it didn't work before maybe the pump is faulty

 

[proplumb]

when I checked the system the hw came on and the upstairs rads came on only with the hw as the valve was only opening to the heating circit when there was a call for hw. The pump works fine.

 

[paul H]

sounds like the electrics are wired incorrectly re check operation of m/v and room/cyl stat

 

[Bernie2]

Check pins in downstairs trv's aren't stuck down. Very common fault.