We can hear the timer on our three year old Grundfos hot water recirculating pump humming. However, the motor itself is not turning. Two questions:

1. Can just the motor be replace, or must the entire pump be replaced?

2. We have had the pump plugged into a three prong grounded remote so we can go to the window and turn off the pump when we go to bed or out for an extended period. Would using the remote cause the pump motor to fail?

There is a large "crew-like-cap" in the middle of the pump. Unscrew it. Few droplets of water will drip out. Once you remove this "screw", you will expose shaft or the rotor. It should be turning. If it is not, than take screwdriver and push it inward and turn in clockwise. Rotor should start turning. Screw back in the large "screw". That should do. Let me know how you did. Back to you. Milo

My Grundfos hot water recirculating pump is red. It has a large gray Grundfos name plate (bigger than a silver dollar) on it. I do NOT see a "screw-like-cap".

Is it under the name plate? If so, how do I remove the name plate?

Look better, every pump has it . It is a Bleed Screw. See the pic. Back to you. Milo

Ok, so using your picture I was able to pop the Grundfos plastic name plate off (it had just 4 little tabs).

Now, I am looking at a solid metal unit where the name plate was. Sorry, No screw.

When you popped off the plate, does it have hole in the middle ? Like 3/4"-1" large ?

Yes it does!

Great, so that tells me there should be a removable large screw in the middle of the pump rotor that accepts flat screwdriver. Look closely again.. Back to you

The opening is the size of a quarter. It is VERY smooth - no screw slot. I tried to gently pry it off without any xuccess

It should go... It may be just pushed in and holding in on O-ring... take skinny flat screwdriver and try it again...

Here is better pic of that screw...

Thanks for your effort. However, I tried and tried and even bent my screwdriver. But, the cap just will not come off.

Can u take a picture of it and post it ?
Or is there a model number you could post for me so I can look it up ?
Back to you...

How do I attach a photo?

P/N 59896288 Mod. CS-1

That's a Production Number...
The model # should read something like : UF-1528

To attach photo:
1. click on "Go Advanced"
2. click on "Manage Attachments"
3. click on "Browse"
(look up your pic.. )
4. click on "Upload" and wait few seconds for pic to upload
5. click on red bar "SUBMIT Answer"

Here are the pictures"

Can you read for me the "TYPE- UP ................. / TLC " info ? It is not legible. Thank you.

Up15-10su7p/tlc

Ok, I read the instructions. It is retrofit pump with Comfort valve installed somewhere in your bathroom under the sink. There is no bleed button. ( you bleed it by simply opening hot water faucet anyplace in your house )

First, I would try to PUSH that middle button INWARD. See if it goes.

Since you cannot remove that middle "button" than you will have to take the pump apart. You do so by closing water and unplugging electrical. Remove 4 HEX screws. Once the rotor is exposed, clean it, flush it and reinstall it. Spin it by hand. It should turn easily and freely. It most likely got stuck on a small piece of debris that prevents it from turning. Then, reinstall the rotor and body.

Don't forget: you HAVE to turn water and electrical OFF before you touch anything.

Back to you / Milo

Thank you. I pushed the button but nothing occurred.

So, taking it apart will be a project for another day.

When you pushed on it - did it go in a bit ?

The rotor will stop on just about any small piece of debris that travels in your plumbing. Sometime it clears itself, sometimes you clear it by pushing that button. Since your pump doesn't have an operable button, you will have to take it apart. It is not a big deal, should take 10 minutes - but can be a little "project" for a homeowner. Let me know how you did. Good luck. Milo

Hi, I work for Grundfos in our Olathe, KS office. Hopefully I can shed a bit more light on your situation.


We can hear the timer on our three year old Grundfos hot water recirculating pump humming. However, the motor itself is not turning.

This pump (correctly identified above) is extremely quiet. Unless you have a device that indicates whether it is running, or you have a very quiet environment around it, it will be difficult to tell. Chances are good that you won't be able to hear it. In fact, if you can hear it, there may be a problem. Is it not functioning correctly?


1. Can just the motor be replace, or must the entire pump be replaced?

For this system, we have no replacement parts (they would be similarly priced to a complete replacement), so if it indeed needs repair, then the entire unit will need to be replaced. By the looks of your nameplate, it is beyond the warranty period. But again, what leads you to believe that something is wrong?


2. We have had the pump plugged into a three prong grounded remote so we can go to the window and turn off the pump when we go to bed or out for an extended period. Would using the remote cause the pump motor to fail?


Short answer: no. It looks like you are using the timer, though, so if this remote system cuts power to the pump, then your timer will be thrown off every time you use it, because the timer uses the same power supply. If you are going to use the remote only, and not the timer, then just leave the timer off. Otherwise, the pump may not run when you expect it to run.

Does that help solve your problem? Post here if you have any other questions.

- Josh

Josh,
Thanks for your information. Sorry for a delayed reply (our PC crashed & has just returned from the shop).

I can tell that the recirc is not working in two ways:

(1) the recirc "rumbles" when running and is quiet when not running. The recirc no longer rumbles when running (but I can put my ear to the timer and hear it run).

(2) we no longer get instant hot water at the two faucets where the valves are installed.

Also,I was told that the following might be a far less costly solution than having to replace a nearly new recirc - I could remove the four screws holding in the motor and see if a piece of debris was caught in the motor.

Is it typical that a Grundfos Hotwater Recirculator would need to be replaced in 3 years?

A noisy Grundfos circulator is a sign of a problem. Could be air or debris trapped in the pump. Air is somewhat common, but we design our products to last a minimum of 10 years, so it's unlikely that there was a product failure. I saw a post a few weeks ago where someone was replacing a circulator that had been in service for 27 years.

Removing the screws (AFTER draining the system and shutting of the supply!) will get you into where the impeller is exposed. You should be able to pull the impeller and rotor assembly out by hand, or maybe with a light pry with a Flathead screwdriver.

If there was something that got into the space between the rotor and stator (inside the motor) then you'll see scratches or marks. It should be a smooth, stainless steel surface. If you decide to pop it apart, post a few pictures.

Ok, my wife and I opened the Grundfos yesterday. We removed the four screws and then removed the timer/motor assembly. We inspected the blades and could not find any obstruction. We were able to spin the blades freely. In addition, we plugged it in for 1 second and the motor turned.

We reassembled the Grundfos and turned it on. It appears to be working at this time.

As a side note, we have had the Grundfos for three years and have always heard a "swooshing" noise when it was running. Now, we hear nothing.

Thanks to all of you for your help.

Ok, my wife and I opened the Grundfos yesterday. We removed the four screws and then removed the timer/motor assembly. We inspected the blades and could not find any obstruction. We were able to spin the blades freely. In addition, we plugged it in for 1 second and the motor turned.

We reassembled the Grundfos and turned it on. It appears to be working at this time.

As a side note, we have had the Grundfos for three years and have always heard a "swooshing" noise when it was running. Now, we hear nothing.

Thanks to all of you for your help.

Glad you got it working normally. Must have had some air trapped in it. I hope it lasts for many years to come.

The Grundfos has been running continuously and working flawlessly for a week.

One, last question about saving electricity - Should I turn it off at night? Should I turn it off when we go on trips? (My bother-in-law's plumber said that he should never turn off his Grundfos.)

Thanks again for all your help.

The Grundfos has been running continuously and working flawlessly for a week.

One, last question about saving electricity - Should I turn it off at night? Should I turn it off when we go on trips? (My bother-in-law's plumber said that he should never turn off his Grundfos.)

Thanks again for all your help.

It's perfectly OK to turn it off. That will save you a lot of electricity - if you're using an electric water heater (mainly from not heating up so much water). The same applies when going on trips. The pump has a timer built into it, so you can set it to be on whenever you want for a 24-hour period. I'll give you an example.

Let's say you get up at 6, go to work at 8, then come back at 6, and go to bed at 10.

I would recommend setting the pump to come on an hour or so before you expect to be using hot water (you may need less time for a smaller home). So, in the example above, I would have the pump come on at 5 a.m. and turn off at 8 a.m. then turn back on at 5 p.m. and off again at 10 p.m.

That way, the pump would run for 8 hours a day instead of all 24.