Grundfos Alpha v UPS sorry cross post

[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.