Grundfos UPM3 FLEX AS 25-75 130 AZA

[wiggers42]

I was wondering if someone could explain the "performance" settings of this pump please. It was installed 4yrs ago but I've not been convinced it was set up properly.

It has a green light and two yellow ones, which I think means "low medium performance."

This is for an underfloor heating system with two loops.

Thanks

 

[martygturner]

It would appear from the manual that unit can either operate in a switched mode or constant mode...the timing of the green light blinking denotes the mode the pump is in.

See page 12 onwards...

https://api.grundfos.com/literature/Grundfosliterature-6821080.pdf

 

[wiggers42]

The green led doesn't flash. Also there's only one of them, not two as in the manual you referred to.

 

[MNW67]

The green led doesn't flash. Also there's only one of them, not two as in the manual you referred to.

Yours looks like an older version. To find out what the settings are, it looks like you push the button on the front. Can you note which ones are lit + colours. Just press it once, quickly, don't hold.

 

[wiggers42]

The LEDs are lit all the time, see photo. Leftmost is green and then the two adjacent ones are yellow. This corresponds with "Constant Curve" in the table you show. I've seen another table where this means "low-medium performance."

I was hoping someone here would understand what the different settings mean and how they should be set.

 

[MNW67]

Have you pressed the button? It should change what you see. Take a note of lights and colours after pressing the button. Just press the button once quickly.

You are in Performance View. Pushing the button should take you to Settings View.

 

[wiggers42]

When I push the button I get:
Red, yellow, off, yellow, yellow.

 

[wiggers42]

I've found a section in the manual and quick guides that might be relevant. The curves in the settings in the Quick Guide don't correspond with the recommended setting (Auto) in the main manual. So I'm wondering if it's the wrong spec pump for underfloor heating?

 

[MNW67]

Red, yellow, off, yellow, yellow.

That combination of lights means the pump has been set to run as a 6m head pump, and that it is being externally controlled.

This pump can be set at 4m, 5m, 6m or 7.5m. So yours is set at level 3 out of 4. And then, in addition, the pump is being further controlled by an external device. That's what the two yellow lights on your original photo show. They mean it is running at between 25% and 50% of the maximum it power it can give on the 6m setting. That output is being set by an external device. I don't know what that device would be.

 

[MNW67]

I've found a section in the manual and quick guides that might be relevant. The curves in the settings in the Quick Guide don't correspond with the recommended setting (Auto) in the main manual. So I'm wondering if it's the wrong spec pump for underfloor heating?

What you are looking at is a Constant Pressure (CP) mode. CP is often recommended for UFH. Your pump doesn't have that option.

Are you unhappy with how it's working?

 

[wiggers42]

That output is being set by an external device. I don't know what that device would be.

What you are looking at is a Constant Pressure (CP) mode. CP is often recommended for UFH. Your pump doesn't have that option.

Are you unhappy with how it's working?

The only control is a Hive receiver and AFAIK that is simply on/off. It seems to take a long time to respond, although I know these systems can take a while, but the temperature seems to vary quite a lot across the floor too.

 

[wiggers42]

There is a white box over to the right, but I think that is just an electrical junction box:

 

[MNW67]

The only control is a Hive receiver and AFAIK that is simply on/off

It doesn't really make sense, anyway, because I can see the connection on the pump, where I thought an external controller would attach, is empty. But the lights show it is being controlled externally.

Often a pump like this would be found inside a combi boiler, and would be controlled by the fan speed.

 

[wiggers42]

Is that what this is for?

What would you connect to provide control in this setup?

 

[MNW67]

Is that what this is for?

I thought it was.

What would you connect to provide control in this setup?

I don't know. That's why it is confusing. AFAIK, UPM pumps are made for OEMs like boiler manufacturers. I didn't know they were a retail item. Who installed the UFH? e.g. a local engineer.