Grundfos 15 60 pump intermittent

[BBT67]

I have a Grundfos 15 60 pump which seems to be intermittent. It has got an manufacture date of September 2004 so I guess its been fitted for about 6 - 7 years.

Anyway, it stopped working a few days ago. I took to bleed cap off the pump and turned the impeller (if that is what it is called) with a screw driver, it was stuck but started to turn freely easy enough. The pump then worked fine for 24 hours.

It stopped working, so I checked to see if it was stuck again but it was free. I tapped it lightly and it started working. It now runs for a few minutes and then stops, there is power (240v AC) for the pump to run but is doesn't, if you tap it it runs but stops a few seconds / minutes later but it should still be running.

The pump gets extremely hot and the CH systems is noisy when starting and stopping, I bled the radiators - the water was clear.

Any idea why the pump is intermittent?

Why the CH system is noisy?

Thanks in advance.

 

[tryitandsee]

http://net.grundfos.com/Appl/WebCAPS/custom?search=UP, UPS Series 100&userid=GMA&lang=ENU

For the cost of a new pump, it's worth just replacing like for like.
Follow the Grunfos web site for help. (Gundfos have made their web site more complicated by the looks of things)

Look at the 'siting of circulators' as often or not, they are not oriented correctly. The bearings are water lubricated and the pump has to be positioned as diagram. Check to see if your existing one is, that may explain noise/wear etc.

Noise from boiler may be just the water not circulating quickly enough due to failing pump.

If both isolating valves are working, an easy enough job. If not, more involved

 

[flameport]

Any idea why the pump is intermittent?

It's broken. Replace it.

Why the CH system is noisy?

The pump isn't circulating the water properly which will cause the boiler to overheat and possibly be damaged. Replace the pump.

 

[BBT67]

Thank you for the replies.

I took the pump apart. One of the electrical connectors where the capacitor terminates had totally burnt out (that why a light tap and is made electrical contact and worked again for a short while), nothing for it but a new pump.

Fitted a new pump today, after cleaning system, everything working fine now.