One pipe and two pipe system ??

[RayPlumb]

Have a central heating dilema. Current central heating not working properly.
Old Oil boiler with flow and return 15mm and pump on return? Is this a one pipe system? Can't tell as tails go into floor from bottom rads (down stairs)
Between the pump and the boiler is tees off the flow and return to upstairs rads on new two pipe system. which currently only works on convection when boiler heating hot water.
Which is the best way to rectify this. If i put a second pump and bypass valve on flow to upstairs, will this work or will it just interfere with ground floor if single pipe system.
Attached is a diagram of c. heating. Any suggestions would help.
😕

 

[stevetheplumber]

from that diagram id say just move the pump to the other side of the tee i.e. closer to the boiler in practice it may be easier to move the tee to the other side of the pump

 

[Puddle]

Well system pipework should be all up dated and controls fitted to make more efficient,taking away the green issue,fuel is not cheap anymore and set to keep rising
But until then
How about fitting tee to up stairs return pipework before the pump and balance

 

[RayPlumb]

Well system pipework should be all up dated and controls fitted to make more efficient,taking away the green issue,fuel is not cheap anymore and set to keep rising
But until then
How about fitting tee to up stairs return pipework before the pump and balance

If ground floor is a one pipe system will this still work or will the pump just circulate round the one pipe system ?
Thanks..

 

[Puddle]

If ground floor is a one pipe system will this still work or will the pump just circulate round the one pipe system ?
Thanks..

Yes it will still work,the pump will pull through both circuits

 

[stevetheplumber]

If ground floor is a one pipe system will this still work or will the pump just circulate round the one pipe system ?
Thanks..

yes will work may need a bit of balancing to get right