Replacement pump - Grundfos UPS 3 v Alpha 1

[Gasguru]

That's worrying! My UPS2 seems to be OK (so far!), so does the boiler. Mine has the usual 3 wires. The pump and boiler both come on via one of the stats, so hard to see how the boiler pcb could be damaged, but I suppose there could be voltage spikes back from the pump. And oilski thinks it's OK.

When I replaced the UPS 15-50 there a lot of clag inside and behind the impeller. I cleaned it up and pretty sure it's OK now. I keep it as a spare but if I thought the UPS2 posed a risk I'd change it anyway.

On a heat only boiler or some system boilers where an additional pump is required the relay on the boiler pcb will switch the pump..and those contacts may not have been designed to cope with high surge currents on high efficiency synchronous pumps...hence the failures. The same issue presents itself with timeclock relays and maybe zone valve microswitches.

Oilski must be mistaken...UPS2 has a ton of electronics with a large heatsink on the side..there's been endless discussion in the combustion chamber about these pumps.

Deblocking means seized....the translation from Danish many years ago was wrong and now all pump manufacturers use this incorrect term. Modern high efficiency pumps have these "deblocking" modes as they are more prone to seizure (tight tolerances, very high speed small impellers) and the impeller is not always accessible from the front...although some Grundfos have a small Pozidrive screw.

EU are eco mad but don't possess the intelligence to see when they are being Greenwashed.

 

[fixitflav]

On a heat only boiler or some system boilers where an additional pump is required the relay on the boiler pcb will switch the pump..and those contacts may not have been designed to cope with high surge currents on high efficiency synchronous pumps...hence the failures. The same issue presents itself with timeclock relays and maybe zone valve microswitches.

Thanks for that. it's reassuring. I don't have any of those controls so hopefully I'll be OK.

EU are eco mad but don't possess the intelligence to see when they are being Greenwashed.

I couldn't agree more. Most people aren't bothered about a few % points on efficiency, if it's at the expense of worse reliability and shorter life. Specially when it's led by German practice which doesn't apply in UK. I used to be a big fan of Grundfos but if they stop doing a basic pump I'm going off them. All I need is a basic pump with 3 speed settings.

 

[ollski]

Guilty as charged, I meant ups 15/50 or 15/60