Grundfos UPS2 15-50/60 circulating pump problem

[Muttontop]

Hi, I'm new to this forum so I hope I've posted this in the right place. I installed a Grundfos UPS2 15-50/60 (part number 98334549) circulating pump into my oil fired central heating system 4 years ago. Recently on the boiler firing up the pump has not started, there is an intermittent ticking sound as though the pump is trying to start but can't. After about 10 to 15 minutes the pump will start and continues to run until the system turns off. This is currently not causing me any issues, other than worrying that there is something waiting to happen. My thoughts are that it may be the run capacitor not having enough umph to start the motor turning but I'm not sure why the temperature of the pump (as this seems to be a factor) results in the pump then running. Having looked into the top of the control box on top of the pump I cannot readily see the capacitor (on the Grundfos pump I replaced the capacitor was readily visible and easily removed/replaced) and I was wondering if anyone on this forum had any advice on how to replace the run capacitor in this particular model. Any help or advice would be greatly appreciated.

 

[John.g]

I think these type of (smart) pump motors may not have a capacitor as they are actually a brushless DC motor.
If you isolate the pump electrically and shut the two isolation valves you should be able to then carefully remove the pump head & impeller and it may then only require a good clean up.

 

[SimonG]

What's your central heating water quality like? The new pumps dont like muck.

 

[ShaunCorbs]

sounds like the capacitor is weak / dead

 

[SJB060685]

Does sound like a capacitor fault. They can be tested a couple of ways, either with a multimeter set to test capacitance or any multimeter set to read resistance. Any doubts about locating the cap then contact Grunfos, although its got to be there in the control assembly.

 

[Muttontop]

Thanks for all the replies. Water is clean enough so I don't think it is that, as I said I think the problem is the capacitor but don't know how to get to it in this particular pump. Tried contacting Grundfos but they were no help. Anyone out there with any suggestions as to how to locate it (if it exists!!!), need to find it before I can test it!

 

[John.g]

Grundfoss UPS2 15 50/60 - delayed start up

I have a Myson Apollo Fanfare 30-50S boiler mounted in an airing cupboard on my landing. For many months, the boiler had been making a loud groaning noise whenever the burner assembly ignited. I then changed the pump (about 3 weeks before Christmas 2014) to a new Grundfoss UPS2 15-50/60 130 and...

www.plumbersforums.net

 

[Last Plumber]

There was an issue on a pump manufactured around that time. A few I came across had a component that didn't like energy spikes. If you are at the end of the 'grid' or have old equipment which could interfere with the supply to the pump, it may be that. Can't say for certain but it sounds like it.

 

[Brambles]

I think that pump is a DC Permanent Magnet so does not have / need a capacitor to start. Having said that, if you have removed the cover and cannot see a capacitor - go no further. If it has a capacitor it will be easily accessible.

 

[SimonG]

If its pulsing it's in purge mode. Sure I read that in the big instruction book that comes with them.