Question on Grundfos Pump

Users who are viewing this thread

Amovida

New Member
Messages
5
Reaction score
0
Points
1
Location
80302
Hello and hope everyone is staying warm this winter!

I have 2 Grundfos circ pumps (1 per zone) on an old Triangle Tube Prestige 110 boiler on a house we purchased relatively recently. One of the pumps appears to not be circulating as that zone is not warming.

First I checked voltage to the pump and I am getting 120V when the thermostat calls for heat.

I pulled the large silver screw from the back of the pump housing and you can see the end of what I assume is the impeller. It has some marks on it as if it were meant to be turned with phillips or a screwdriver. When I put pressure on the end of the impeller it begins to turn under power from the motor. When you back of the pressure with the edge of the screwdriver it stops turning.

Said in another way it the impeller only begins to turn when there is moderate pressure on it. I understand that when you replace the silver end cap it will create some pressure on the end of the impeller.

I guess my question is...is this by design or is this a pump that is wearing out and needs replacement?
 

Amovida

New Member
Messages
5
Reaction score
0
Points
1
Location
80302
Good morning and thanks for the reply. The circ pump is a 1/25hp Grundfos pump. I don’t have the pump in front of me at the moment but I’m pretty sure the model number is UP 15-10F.

 

Amovida

New Member
Messages
5
Reaction score
0
Points
1
Location
80302
What I am wondering is why does the impeller spin...once you've put a bit of pressure on it via a screwdriver? Does anyone have any direct experience with this with Grundfos pumps?

I imagine the phillips/screwdriver fitting on the end of the impeller is there so that if the impeller gets bound up with any debris you can remove the cap and manually move the impeller to clear the debris.

Any thoughts as to whether this is normal operation (the part where it begins to spin with a little pressure) or not would be appreciated. Thanks and enjoy your Sunday!
 

Jeff H Young

In the Trades
Messages
9,119
Reaction score
2,297
Points
113
Location
92346
not understanding the question Not an expert on this pump but the impeller should turn with cap removed
 

Amovida

New Member
Messages
5
Reaction score
0
Points
1
Location
80302
Rereading what I wrote I see where what I said may not be clear. Let me give it another shot.

When you remove the silver slotted end cap that is about the size of a quarter it exposes the end of the impeller. This impeller/pump is getting power but the motor power does not spin the impeller until you push it in with a flat screw driver blade. Then the motor power takes over and it spins under the pressure of the screwdriver as long as the you hold the screwdriver in a way it does not catch on the slots on the end of the impeller. For whatever reason it only begins to spin under this pressure. Looking at the cap it seems to force the impeller in this position when it’s put back in its place by threading it on. I’m wondering if this is normal operation or if this is a sign of a malfunction. Thanks to anyone who helps with this…and I hope everyone is staying warm!
 

Jeff H Young

In the Trades
Messages
9,119
Reaction score
2,297
Points
113
Location
92346
I dont know if its normal I cant remember attempting to run pump with cap removed
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks