Grundfos CH Pump strip down

[Parkmanto]

I searched in vain for a solution to my central heating problem. My experience may help you.
Symptoms were no heat getting through to upstairs radiators at the end of the line of an open vent system. Went through lots of flushing and checking for a blockage in the radiator pipe-work to no avail.
CH pump was a fairly new Grundfos UPS 15/60. In the end before ripping up the floor boards decided to take out the pump and strip it down. Not a difficult job – four Allen bolts and the housing was off. Amazed to find it jammed full of crud including some very large flakes.
Puzzled as to why I had not had this before but noticed the new Grundfos pumps are smaller overall and the impellor more so, not allowing the smallest particles through as in the past.
Couple of tips – make sure to note direction of pump in the pipe work and mark the casing of the pump housing and the body to make it clear which way it goes back on. Also I used a nylon cable tie to get the muck out without doing damage to the impellor. Hope this works for you.

 

[seco services]

and mark the casing of the pump housing

pump housing already has a direction arrow.

 

[Parkmanto]

Hi
The main housing with the pipe work connections - has two arrows either side. Need to note these in terms of getting it back in the right position, particularly if not familiar with the flow direction of the system.

The main pump unit once seperated has no markings and can fit back in four different positions onto the housing. Not sure this matters, though having the electrical wiring in the same position could be an issue.
Hope this is of help - it caught me out.

 

[DP]

OP, you should be more concerned with the debris in the pump. Removing the pump head is child's play