Replace central heating pump

[JackK]

I have a heat only vented boiler and water cylinder - I have only one pump from the looks of things just near my boiler

It does work but looks old and I want to replace it at the same time as adding a magnaclean filter

Is the grudos Grundfos UPS3 15-50/65 130 a direct replacement and how easy is it to swap out - I can drain the system easily but I have 28mm pipework from the boiler and not 22mm. Will this need to be wired into the old boiler at the same time - I imagine yes

 

[CBW]

It looks like the Grundfos will be direct replacement and they’re not usually difficult to replace. As for wiring, they’re usually wired into the wiring center afaik. The pipe size isn’t an issue unless you’re replacing the valves, in which case get some 28mm pump valves (might be a good idea, as I think those slotted screwdriver types can leak for fun).

 

[Mottie]

My Grundfos pump has been wired directly to both boilers we have had - a Potterton profile and a Vaillant ecotec. The Grundfos should come with a short wiring loom and you can just connect to that from your existing pump wiring - just L, N and E.

 

[JackK]

My Grundfos pump has been wired directly to both boilers we have had - a Potterton profile and a Vaillant ecotec. The Grundfos should come with a short wiring loom and you can just connect to that from your existing pump wiring - just L, N and E.

Brilliant thanks - Did not feel comfortable messing with the wiring box - Will just use a wago connector block and slot in - Will also replace the valves - Thanks again this site is brilliant

 

[Harry Bloomfield]

Will this need to be wired into the old boiler at the same time - I imagine yes

Modern boilers directly control the pump, so they can keep the pump running for a little while after the demand for heat has been satisfied and the boiler has shut down. Idea is one of drawing the maximum amount of heat from the boiler heat exchanger, as well as cooling it down to prevent heat build up.

Older boilers, had no such control, but relied upon 'demand for heat', to control both boiler and pump, along with the powered valves.

 

[Dereekoo]

When you say wired into the old bolier is this what happens at the moment or does everything thing ( wiring wise) go to/from a wiring distribution box which should then just be a question of connecting the new/old wires like for like

 

[JackK]

When you say wired into the old bolier is this what happens at the moment or does everything thing ( wiring wise) go to/from a wiring distribution box which should then just be a question of connecting the new/old wires like for like

It does go into a wiring box - But I dont want to disconnect it unless I absolutely have to - I will try and reuse the cable and see if that works out