Grundfos Central Heating Pump Plan
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There is info on the Grundfos web site. Just type "pump plan" into the search.
The main thing is that it eliminates motorized valves and flow rates for the CH and HW circuits can be separately controlled. It is still using the old fixed 15-50 pumps. There isn't a version using the alpha pump for CH.
On a smallish domestic with one heating and one hot water circuit.
The advantages are no motorised valves to plumb/wire in.
It hasn't taken off over here because Grundfos haven't supported it in the merchants etc. It also cannot be upgraded, (other than changing to a 15.60 head) so if you wanted to add a zone, you can't without throwing it away.
I have fitted it on a few of my domestic installs, but I always get a call from the installer (if they haven't fitted one before) saying 'what's this'.
If I had specified a normal zone valve set up I would save the call.
And lastly, customers are not familiar with it. So if you quote for it, and two other installers quote for zone valves, the customer tends to worry and you may not get the job.
Which gets back to Grundfos not marketing it hard enough. I think it is a sensible solution, well made, the kit includes everything you need inc wiring centre, but a difficult one to sell in the UK.
The advantages are no motorised valves to plumb/wire in.
It hasn't taken off over here because Grundfos haven't supported it in the merchants etc. It also cannot be upgraded, (other than changing to a 15.60 head) so if you wanted to add a zone, you can't without throwing it away.
I have fitted it on a few of my domestic installs, but I always get a call from the installer (if they haven't fitted one before) saying 'what's this'.
If I had specified a normal zone valve set up I would save the call.
And lastly, customers are not familiar with it. So if you quote for it, and two other installers quote for zone valves, the customer tends to worry and you may not get the job.
Which gets back to Grundfos not marketing it hard enough. I think it is a sensible solution, well made, the kit includes everything you need inc wiring centre, but a difficult one to sell in the UK.
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The HW circuit and CH share the same pump on a conventional system.
But the pump will run for longer, because the boiler output is being shared.
In pump plan there will be times when both pumps are running, but this will be a relatively short time.
Fianlly, the synchron motors in the MVs don't run on air and they are powered open all the time they are energised.
But the pump will run for longer, because the boiler output is being shared.
In pump plan there will be times when both pumps are running, but this will be a relatively short time.
Fianlly, the synchron motors in the MVs don't run on air and they are powered open all the time they are energised.
Grunfos have missed a trick because they dont market the control circuit on its own.
I think that it provides a ready made standard solution to a problem if you have to use two seperate pumps on a system but need a boiler pump over run connection.
I bought a PP to reuse the two heads as replacements and the control part for this application. The alternative would have been to build a control specifically for the purpose which I wanted to avoid.
Tony
I think that it provides a ready made standard solution to a problem if you have to use two seperate pumps on a system but need a boiler pump over run connection.
I bought a PP to reuse the two heads as replacements and the control part for this application. The alternative would have been to build a control specifically for the purpose which I wanted to avoid.
Tony
The Grundfos documented answer to the need for two heating zones is to add one 3-port MZV on the heating side. I've never done that myself, but I don't see why it can't be done.
Yes, I suppose that could be done.
I haven't investigated how you would configure the wiring... I imagine you would use the orange wire on the three port to simulate a call for the CH pump.
But at the end of the day, pump plan is only really designed for two channel operation. On larger eg: light commercial jobs you effectively create your own pump plan with a header and a few relays.
I haven't investigated how you would configure the wiring... I imagine you would use the orange wire on the three port to simulate a call for the CH pump.
But at the end of the day, pump plan is only really designed for two channel operation. On larger eg: light commercial jobs you effectively create your own pump plan with a header and a few relays.
the Grundfos pump plan saga goes on.
July 2016 Worcester Bosch Greenstar boilers wiring guide shows the pump plan for 2 pump systems on pages 13, 25 and 61 so anyone with a 2 pump system buying one of those boilers will find that Grundfos no longer make the wiring centre. So you end up with a boiler that no one knows how to wire in so that the pump over-run works!
If I'm wrong and someone can tell me - then shall be eternally grateful as have a new Ri 24kw on the wall and can't trigger the over-run without some wiring / relay info!
July 2016 Worcester Bosch Greenstar boilers wiring guide shows the pump plan for 2 pump systems on pages 13, 25 and 61 so anyone with a 2 pump system buying one of those boilers will find that Grundfos no longer make the wiring centre. So you end up with a boiler that no one knows how to wire in so that the pump over-run works!
If I'm wrong and someone can tell me - then shall be eternally grateful as have a new Ri 24kw on the wall and can't trigger the over-run without some wiring / relay info!
You need to be competent to work on these boilers. Call a professional that understands how the two products work and is gas safe registered.
It's not rocket science.
It's not rocket science.
Tony Glazer posts on here and will do it for £84.
Not sure if he is vat registered though.
Not sure if he is vat registered though.
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