Grundfos UPS4 commissioning problem.
Fitted a new UPS4 onto an existing unvented system with some trapped air.
Pump limped into life and wouldn't even pump with enough pressure to clear trapped air from coil in hot water cylinder - let alone make enough effort to pump radiator circuit of 4 rads.
Spoke to Grundfos customer service who treated me as as if I've never fitted a pump, assuring me that the UPS4 is s "smart pump" and that air prevents the pump pumping at full speed.
This may be true, but ...
The UPS4 pump seems to be lacking a commissioning setting to put it on full power to perform an initial setup of a heating system.
Wasted one and a half hours trying to get the pump to kick into life.
Should have opted for a basic pump instead - would have got the system running in 5-10 minutes!
UPS4 pump is no improvement on earlier products.
Nobody at Grundfos of the 3 individuals I complained to seemed to think there's an issue.
Would steer clear of this pump given choice.
Reply from Grundfos
Hi Michael,
Thank you for sharing your thoughts on the UPS4. We appreciate your feedback and the opportunity to clarify how the pump works.
The UPS4 is designed as a smart pump, which means it automatically adjusts its speed based on system conditions. However, trapped air can significantly affect performance during initial setup.
To help in situations like this, we recommend the following commissioning tip:
Close the valve on the flow side of the pump and allow gravity to flood the pump and remove air.
With the valve closed, you should see the wattage display increase as water fills the pump.
Once the wattage rises sufficiently, slowly open the valve on the flow side while the pump runs at full speed. This should clear the air and restore normal operation.
Please email us at grundfos-uk@sales.grundfos.com. Alternatively, please share your contact details, and our colleague Tom will reach out to you directly.
Best wishes, Maria