We had a town water issue that resulted in very little to no water pressure in the home. Ever since our Grundfos recirculator isn’t functioning properly. We’ve tried bleeding the air out of it, but not having any luck getting it to kick back on for us, just a quiet buzzing.

The hot water heaters are running perfectly, but we are not getting any hot water anywhere in the home. Shouldn’t we still be able to? Should just take longer?

On occasion we will in the kitchen that is just below the tanks in the attic. We can’t get a plumber here for a couple days and need hot water for showers!

Another note, we did quite a bit of construction on our home after we purchased and every time they shut the water off we had a problem similar to this happen. Not sure what they did each time to repair it but we are on our own right now and I’m desperate for a warm shower again! It’s been three days.

enter image description here

  • If the recircualtor ran without water, it might be burned out. Replacing it should not be to hard, if the power to it and the water is turned off. Should still get hot water though, unless the cause is a blockage in the pipes.
    – crip659
    Nov 6, 2023 at 19:47
  • I do think we may need to replace but until then, I just don't know why we aren't getting hot water - just slower to reach the faucets. As I mentioned, this problem has occurred before too, there is not an issue with blockages in the pipes. I added a photo in case that helps anyone help me??? Thanks so much!!
    – Lori
    Nov 6, 2023 at 20:00
  • Do you have any pressure gauges? What is your pressure reading? Recirc pumps can deal with at most 20' of head pressure so assuming you have a basement and two level house you are already maxed out on the head pressure. Now the city is supplying water at no pressure so you need to know the elevation drop to the source. You'd need a booster pump installed to increase pressure for your recirc pump to work properly. recirc pumps are tiny and not expected to provide pressure to your house. Nov 6, 2023 at 20:18
  • Whether or not you can get any flow without the pump running would depend, I think, on the type of impeller used and it's position when stopped.
    – SteveSh
    Nov 6, 2023 at 20:20

2 Answers 2



This is somewhat at the limit of picking things out of the resolution of your photo, but is the red circled item turnable with a screwdriver? I think you have the flanges with built-in shutoffs. Both flanges should have one, only the top one is slightly visible.

Turn off power to the pump if you have not already done so. Turn both of those 90 degrees, so the slot is parallel to the flange. That should take the recirculation loop entirely offline, and the "regular" hot water piping should start working normally. It also makes removing the pump possible, but I don't think you should need to do that just to get hot water out. What I suspect is that the check valve usually associated with a recirculation system is not working, and you're drawing cold water through the recirculation pipe. Shutting those valves should stop that.


Is the pump on the side pushing hot water out, or on the side drawing cooled water back? If it isn't running it will present a restriction (at least) in flow and you may be drawing mostly from the unheated side of the loop. (I'm presuming there isn't a check valve in the return side of the loop.)

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.