Help heating not working downstairs tried replacing the pump

[query]

Hi! My heating is working fine upstairs but downstairs is very hit and miss. Of the 6 radiators downstairs only 3 work. All radiators have been bleed and drained multiple times. I have fitted a new pump in the boiler but 3 radiators are still stone cold. Any suggestions?
Thank you!

 

[Chuck]

Post a few more details about your system. Are there zone valves controlling the floors separately? Is it an open or closed system? Does it have the correct amount of inhibitor? Is the system water clean or dirty, etc.?

 

[plumberbuckscounty]

This is most likely caused by a problem with your central heating pump and can often happen when your heating has been switched off for a few months.

 

[Murdoch]

When did it last work properly?

Has anything been changed apart from the pump?

 

[Ben-gee]

Pins stuck on trvs...

 

[query]

Post a few more details about your system. Are there zone valves controlling the floors separately? Is it an open or closed system? Does it have the correct amount of inhibitor? Is the system water clean or dirty, etc.?

Pins stuck on trvs...

They have been changed. This was done late last year and since then the heating has only been used occasionally.
[automerge]1602838737[/automerge]

Post a few more details about your system. Are there zone valves controlling the floors separately? Is it an open or closed system? Does it have the correct amount of inhibitor? Is the system water clean or dirty, etc.?

Its an open system. The zone valves are not separate. Inhibitor has been changed twice and the system water is clean.
[automerge]1602838784[/automerge]

This is most likely caused by a problem with your central heating pump and can often happen when your heating has been switched off for a few months.

I just changed the pump. Prior to the pump not being changed none of the downstairs heaters worked. Now 3 are working.

 

[Chuck]

If you close all the upstairs TRVs, does the ground floor start working okay?

 

[query]

When did it last work properly?

Has anything been changed apart from the pump?

Y

When did it last work properly?

Has anything been changed apart from the pump?

Its been over a year since all the heaters have worked. I've been trying to trouble shoot different things.

 

[John.g]

Re three cold rads, if they have the vents in a 1 ins plug then there should be another (blank) plug at the opposite end, suggest (with boiler/circ pump off) shutting both TRV & lock shield valves, de pressurise rad with normal vent to ensure valves are holding then shut it, remove the blank plug and flush separately from either end into a bucket for a few minutes, if/when complete/satisfied run boiler to those 3 rads only and see how you get on.

 

[Murdoch]

Turn off ALL the upstairs rads and see what happens