Radiators hot up, cold down.

[Jimmyjaffa]

Hi all, need a little advice please. Just replaced a diverter valve on a conventional boiler system. Drained system down to enable change of valve, fitted valve and bleed every radiator. Problem I'm having is that the upstairs radiators are getting hot but downstairs are cold. Any ideas please?

Many thanks
Jim.

 

[conny]

Not a plumber/boiler engineer but had this problem a number of years ago. Did you flush through first when re-filling? You may have sludge settlement from the drain down. My solution was to bleed all the rads starting at the lowest and ending at the highest. I then shut off all the upstairs rads and all the lower ones bar one. Turned the heating on and the first rad warmed up. I then went round the ground floor in sequence opening each rad in turn as they warmed up. Once the ground floor was up and running I did the same to the upstairs ones, again starting with the one that was mounted lowest. Bit time consuming but it worked for me. If it doesn't work you may have to drain down and flush through as a possible solution.

 

[picasso]

Or the pump is full of air, try opening the big screw on the front of the pump till you get all the air out. (heating and hot water off and use a towel to catch the drips)

 

[ericmark]

With heating off you can bleed both feed and return by shutting off lock shield valve with TRV open and bleed, then shut off TRV with lock shield open and bleed.