There were actually three different people involved from different companies! The builder laid the floor and main pipework, the boiler installer fitted the pump and connections to the boiler, and the electrician did the wiring. Initially there was a cheap and nasty thermostat that was difficult to use and had a huge null zone. (+/-2deg) The boiler fitter had actually provided a multi-zone Hive system, but the builder overrode that and told the electrician to fit the cheap thermostat that didn't talk to anything else.
Grundfos UPM3 FLEX AS 25-75 130 AZA
- Thread starter wiggers42
- Start date
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I don't think this has really helped answer your question, because the settings lights just don't seem to correspond with what is happening in practice. Somebody else might be able to pull it all together.
There may be some information printed on the back or side of the pump, like a Part Number, which might help narrow down exactly what it is.
There may be some information printed on the back or side of the pump, like a Part Number, which might help narrow down exactly what it is.
Thanks for your help, it has answered a few questions. The other reason I've not found the setup satisfactory is that the boiler seems to be hunting between two "speeds" every five seconds. Is that something to do with the missing control link?
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The boiler is a WB Greenstar 32CDi Compact. Yes, a change in sound, the fans perhaps?
Interestingly, when I search the Grundfos site for underfloor heating it doesn't mention the UPM3, just the Alpha. And on another specialist site it only mentions the UPM3 AUTO variant:
underfloorparts.co.uk
Interestingly, when I search the Grundfos site for underfloor heating it doesn't mention the UPM3, just the Alpha. And on another specialist site it only mentions the UPM3 AUTO variant:
Underfloor Heating Pumps – Underfloor Parts
underfloorparts.co.uk
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Fan or pump, you would think, as the boiler modulates up and down. But not that quickly. I can't say whether there's anything wrong, though.
Something just popped into my head. Looking at the quick guide you posted, you get those same lights whether it has the external control or not. So I think it's safe to say that your pump is set to "Max Curve 3", which is 6 m head. When there is no external control to vary the speed, the pump runs at max speed for that curve, all the time. My best guess would be that the two yellow lights you normally see show it is running between 25% and 50% of the maximum power for the pump (60W), so somewhere between 15W and 30W. Knowing that isn't particularly helpful, though, but you can try and correlate it with the curves below.
When there is no external controller this pump works as a very basic pump with four fixed speeds. There are no other modes like Constant Pressure or Proportional Pressure, and no accurate way of displaying its output. So really, to go back to your original question, there is very little you can glean from the settings.
These are the curves. I don't know if you've seen them.
That's very interesting, thanks. I had seen the curves but not really studied them. The sight glasses seem to show the flow rate at 1.25 l/m, which is 0.02 l/s:
This seems very low! I've made contact with someone at Gundfos now, hopefully they can shed some light next week. I'll let you know what they come back with.
This seems very low! I've made contact with someone at Gundfos now, hopefully they can shed some light next week. I'll let you know what they come back with.
The boiler is a WB Greenstar 32CDi Compact. Yes, a change in sound, the fans perhaps?
Interestingly, when I search the Grundfos site for underfloor heating it doesn't mention the UPM3, just the Alpha. And on another specialist site it only mentions the UPM3 AUTO variant:
Underfloor Heating Pumps – Underfloor Parts
What are the flow meters on the manifold showing ??, are they moving up and down or staying steady?
Its difficult to see exactly what pump you have got but it may be just a basic constant curve (CC) but these pumps operate in constant pressure (CP)
fashion up to ~ 0.8m3/hr (13.33LPM) so if the total of the flow meters is < 13.3LPM the pump is effectively operating in CP mode.
Logically?, then you might think that one green+oneyellow would be set to 4M, one green+two yellows= 5M, (your setting which seems reasonable) one green+three yellows=6M and one green+4 yellows=7.5M. but you don't seem to be able to select these options?.
Anyhow, for the moment note the flow meters and if erratic, maybe try another combination of the LEDs, flowrate/loop should be ~ 2 to 3.5LPM and are adjustable.
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I've not noticed any fluctuations in the flow rate indicators. But I've been looking into them and from this reference it seems as if you can set the flow rate using the red collar:
Underfloor heating manifolds explained
Discover what a manifold for underfloor heating is, how they work and why they are important, as well as how to install them, with our ultimate guide!
www.nu-heat.co.uk
I haven't found the information for the specific manifold I have though.
Not necessarily. It depends on how long the loops are. Do you know?
Good point!! Thanks.
Increase the flowrates to say 2.5LPM, initially open them up to max flowrate, if you can get > 3.5LPM then the pump is operating with plenty of head.I've not noticed any fluctuations in the flow rate indicators. But I've been looking into them and from this reference it seems as if you can set the flow rate using the red collar:
Underfloor heating manifolds explained
Discover what a manifold for underfloor heating is, how they work and why they are important, as well as how to install them, with our ultimate guide!
I haven't found the information for the specific manifold I have though.
It looks like this pump was updated in mid 2020. The speed options and the meaning of the lights changed. So make sure they know you have the earlier version.
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