Boiler Corresponded ONLY to Ground Floor Radiators

Paris18

I will have the heating on upstairs ONLY if I switch on at least 1 Ground Floor's radiator.

When I switch on (e.g. TRV set to max) the Grond Floor Radiator, the boiler responds, and then the pump starts to work. When the pump starts working, the copper pipes going upstairs will turn warm (gradually become hot if I have the Ground Floor radiator switched on for a long time).

I will have no heating on the upstairs' radiators when I switch off all ground-floor radiators.
What could be the issue...?

Bolier = Greenstar 30 CDi; Manufactured = 2011 year;
> All radiators bleed already
> All radiators have just been flushed (by myself; I took them off the wall and flushed them in the garden)
> All TRV and Lockshield Valves have been replaced with a new one
> I flushed the copper pipes too...

## I don't think I have a twin-channel programmer, my thermostat is: Worcester Digistat (the manual is here:
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjFuKODl4CBAxX7U0EAHdAFDuwQFnoECCAQAQ&url=https://www.worcester-bosch.co.uk/support/literature/download/8716114519&usg=AOvVaw0g4Ey89LZo-1OJn68rBB3W&opi=89978449

## I don't think I have a zoned heating (upstairs and downstairs), because I have only 1 thermostat.

pecmsg

Gost flow?
bad flow check?

mattmia2

Answer the question about the fill pressure in your other thread. does water come out of the bleeders on the second floor?

mattmia2

We need to know how it is piped too. Was it a gravity conversion? Is it a monoflow? Is there a bypass at the boiler? Is the circulator actually moving water or has it failed and it is only heating on gravity flow.

JUGHNE

As Matt said what is the boiler pressure, need 12-15 PSI to lift the water up that high.

The pump will not push the water up, it has to be there already.

The pump makes the system work like a ferries wheel, just circulating the water....not lifting it.