rads hot upstairs but cold downstairs

[jasonhunter]

hi,
my girlfriends having a problem with rads downstairs not working at all but upstairs theyare.hot water is perfect.a heating engineer"friend" has replaced the pump but this has made no difference,hes also bled it to no avail,and hes now saying that its problably a blockage and says probably needs pipework renewing,but dosent seem to want to do it .shes had a 2nd opinion from another plumber friend who also indicated that he didnt really know the cause but he reckoned that the zone valve was working as he could hear it switching over.any ideas?

 

[ChrisR]

Did it happen suddenly? Any work been done which caused the system to be frained - before the new pump? Shut all the upstairs rads - do the downstairs ones start to work then?

 

[oilman]

For those who read these posts, note this is another case of changing a pump without diagnosing the problem.

 

[jasonhunter]

Hi,thing is the fitter is a corgi registered engineer who works for the council during the day.Have turned off the working ones but to no avail

 

[jonesey]

Sounds like it may possibly be a blockage in the heating pipework which drops downstairs. Feel this pipework to see if it warms up when heating is on.

 

[jasonhunter]

actually shes just told me that when she turned upstairs off the kitchen rad did feel aired-not hot but not properly cold.what do you think about the zone valve-any diagnostic tips?pls

 

[jasonhunter]

Hi,Jonesy that pipe is warm at top,lukewarm in middle and cold at bottom
do you think physical blockage or airlock

 

[jonesey]

Its probably not the zone valve, if the plumber said its switching over fine. Also you should not hear a rattling from it as this would indicate the ball inside has come off, resulting in restriction of flow, but your plumber friend would have probably noticed this.