Grundfos Pump Plan wanted

[UKenGB]

Having had numerous problems with motorised valves in the past (mostly due to poor design IMO) I was delighted to read about the Grundfos Pump Plan that not only uses 2 pumps that I think is a great idea, but also eliminates the need for any motorised valves.

But as many of you will be aware, it no longer appears to be readily available. So...

Can anyone suggest a source of supply for one of these systems?

What's the best way of utilising 2 separate pumps to do the same job?

 

[Dan Robinson]

You just need too pumps and a couple of NRV's to make the same thing. Wiring centre easily mimicked using relays.

Alternatively use thermoelectric actuators instead of zone valves.

 

[AGAS]

a lunchbox should cover it

 

[UKenGB]

You just need too pumps and a couple of NRV's to make the same thing. Wiring centre easily mimicked using relays.

Alternatively use thermoelectric actuators instead of zone valves.

Could you be more specific about the NRVs and relays. I know what they are, but would appreciate confirmation of their function in such a system.

Also, 'thermoelectric actuators'? Not familiar with those.

 

[Dan Robinson]

Thermoelectric as in like ufh actuators.

Or if two pumps, the nrvs stop circulation when one one pump is off.

The pump plan was no more reliable than an s plan anyway.

 

[stem]

The wiring gets quite complicated if you have a boiler that has an output to control the pump for the purpose of a 'pump overrun'. The boiler only provides one output, so you would need to provide some circuitry, so that only the one that has just switched off gets the overrun signal, and it's not quite as straightforward as it sounds.

If your boiler doesn't have an overrun, then a simple relay that operates in conjunction with each pump will provide a switching contact to control the boiler and provide isolation between the heating and hot water circuits.