Grundfos Alpha v UPS sorry cross post

[Nibber]

Hello, I have just had my 15year old Grundfos UPS 15 50 replaced with an Alpha 1 and the Alpha 1 seems quite a bit noisier than the the old one,
I have a new UPS3 sitting in a box and I am thinking of changing the Alpha 1 for the UPS3

if I understand it correctly, Alpha1 v UPS3
1. Alpha 1 is more energy efficient
2. Alpha 1 is noisier
3 Alpha 1 flow rate is much less

is this correct?
thanks

 

[John.g]

Does your version of the Alpha have the power displayed, watts, W?
Can you post a photo of the running pump with its LEDs displayed, this will show mode/setting.
How many rads?.

1&2 above, NO. 3. YES.,

 

[Nibber]

Does your version of the Alpha have the power displayed, watts, W?
Can you post a photo of the running pump with its LEDs displayed, this will show mode/setting.
How many rads?.

1&2 above, NO. 3. YES.,

thanks for the reply, Yes it does have Watts Displayed &16 Rads, picture attached, say flow rate 2.4m3/h UPS3 say 4 on the Grundfos site, constant III setting

 

[John.g]

thanks for the reply, Yes it does have Watts Displayed &16 Rads, picture attached, say flow rate 2.4m3/h UPS3 say 4 on the Grundfos site, constant III setting

That pump is pumping absolutely nothing at 4W, setting 1 in PP mode.
16 rads, you will require ~ 1 to 1.5m3/hr at say a 3.5M head to service those 16 rads.
Suggest, as a start, setting it to CP2 (second symbol on the right) and setting 2, you will require ~ 25 to 30W, see what this gives you, if < 20W try setting 3, (CP mode)

Have you a link to your pump?.

 

[Nibber]

That pump is pumping absolutely nothing at 4W, setting 1 in PP mode.
16 rads, you will require ~ 1 to 1.5m3/hr at say a 3.5M head to service those 16 rads.
Suggest, as a start, setting it to CP2 (second symbol on the right) and setting 2, you will require ~ 25 to 30W, see what this gives you, if < 20W try setting 3, (CP mode)

Have you a link to your pump?.

Sorry I think I haven't explained correctly, the picture is the brochure, my actual pump is running at 35watts in constant III mode

the brochure picture says flow rate is 2.4m3/h for alpha1 and according to Grundfos UPS3 says 4m3/h

 

[John.g]

Sorry I think I haven't explained correctly, the picture is the brochure, my actual pump is running at 35watts in constant III mode

the brochure picture says flow rate is 2.4m3/h for alpha1 and according to Grundfos UPS3 says 4m3/h

That's your pump curves below, I think.
Wht you have is three constant speed, CC settings, on the left, two PP modes first two symbols, on the right and two CP modes, last two symbols, on the right,

You are saying that you are running it on speed 3, III on the far left, is that correct??, if so at 35watts the pump is circulating ZERO, if you are saying the third LED on the right is illuminated then its running in CP1 mode and 35watts gives a flow of 1.6m3/hr, at a 3M head, is this it?.
To avoid any confusion can you just post a photo as requested.

 

[Nibber]

Here you go picture of actual pump, thanks

 

[John.g]

Here you go picture of actual pump, thanks

Certainly looks as if running in full speed mode so it cant be circulating anything at 35W, the boiler (if a heat only) should only run for a few seconds/minutes and the rads will/should be completely cold IMO, its possible that the pump is full of sludge and choked, just change it to CP2 (far right symbol) and if it runs at ~ 5W then pump sludged up or a valve shut somewhere.
Only other explanation is that its a 35watt pump and not 45/50 watt.

 

[Nibber]

Its a brand new pump and I am sure its working as it should, I'm just trying to understand the pros and cons of the Alpha1 and UPS3, thanks

 

[John.g]

The UPS3 is a far more powerful pump but won't consume any more power than the Alpha1 if running at the same head and flow. As its a bigger pump then it should run a bit quieter than the Alpha1 IMO
Cons, this model has a history of premature failures and disgracefully IMO, does not display the power.

If you don't mind, you might just change the Alpha1 mode briefly to CP2 and note the watts, then revert back, thanks.

 

[Nibber]

thanks for all the replies

 

[John.g]

It's up to yourself but I would suggest returning that pump to wherever you bought it and demand either a refund or a new replacement as there is no change in pump power on any settings, looks as if it is running probably at full speed and the system resistance is then just limiting its power output, scarcely a energy efficient pump and no wonder its noisy.

 

[ShaunCorbs]

I believe it takes a while to do some thinking / calcs and it slowly reduces the speed to match the system needs

Tbh they were a rubbish pump electrics normally go on them first before the motor they were the first gen without the bleed screw in the front

 

[John.g]

This is the flavour of the sort of numbers one might expect from any A rated pump, this is from a Alpha 2, 12 rad system.

 

[John.g]

thanks for all the replies

Looking at those photos again, looks like there are three settings in both PP & CP mode and it is hard to believe that a new pump is faulty, note the watts on CC2, PP2 and CP2, if the power changes then pump OK and one of those settings might be sufficient, probably CC2 or CP2 and will reduce the noise.

 

[John.g]

I think that pump is a 34W, Alpha 1 Model B., thats why all the settings showed the same power.
Its circulating ~ 1.3m3/hr, 21.7LPM at a 4.5M head, (this can be checked by changing to PP2 where the power should fall to ~18W to give 0.9m3/h, 15LPM at a 2.2M head).

The UPS 3 which is a 60W pump will give the 1.3m3/hr on CC2 which will be less noisy but if a greater flowrate is required then it will have to be changed to CC3 which should give ~ 1.5m3/hr, 25LPM at a 5.8M head but might still be quieter than the Alpha 1 as the power at ~ 44W will be less than its 60W max so running a little slower.