I'm looking for some help regarding hot water circulation in my house. House was built in 2005. It stopped working a couple of months ago, which happened to coincide with a kitchen remodel we did. The contractor had to shut off the water during the remodel as well as had to re-light the hot water heater, but say they didn't mess with the recirculation pump(Grundfos). I have no idea if this is the cause, just stating what changed.

It used to take 10 seconds in an upstairs shower. It now takes 60 seconds to get hot water.

Troubleshooting so far:

1. Ensured the timer was on and working

2. Pump vibrates and piping vibrates and is hot based on water flowing up as per flow of pump. Pump is hot, piping is hot above the pump.

3. Opened cap on Grundfos pump and can turn the pump, so it isn't frozen

4. The valves before and after the pump appear to be open. They are the same valve, but one seems to take more turns than the other. One of them appears to be 1/4 turn whereas the other takes 2-3 full turns.

5. I am not able to find a comfort valve installed anywhere, but did find that in the upstairs bathrooms, there are T fittings on the faucets upstairs that seem to hook up the hot and cold. It is unknown if a comfort valve was installed in the kitchen prior to the remodel. I went ahead and installed one in an upstairs bathroom to see if it would help. It reduced the time to getting hot water to 40 seconds. It seems to help, but not actually fix the problem.





At this point, I'm stumped. The pump appears to be working, but I'm not 100% sure. Are there any other troubleshooting steps I should try before calling a plumber.

 

A comfort valve is also known as a bridge valve. There is typically one installed the the furthest point away from the water heater. That valve is thermostatically controlled. It allows the pump to push hot water into the hot water supply pipe to the fixture. Then it goes thru the valve to the cold water line. That valve is designed to close when the water gets to a certain temperature. If it closes too early or is blocked..... you won't get much "hot" water. If the valve gets stuck you'll get too much hot water back into the cold water side.

 

Thanks for the response. I realize now that the T fitting I was talking about is irrelevant to this conversation and is part of the Moen faucet installation. I tried installing the comfort valve and it helped a little bit, but didn't fully fix the problem. Instead of 60 seconds of cold water, it's now 40 seconds. Is it possible the builder of the home did some other technique besides the comfort valve and that is now broken? The comfort valve was brand new, but it's entirely possible it wasn't working.

 

Ok, I was able to get some info from the old owner of the house. As this was a new construction previously, it doesn't need a comfort valve. It has a hot water loop. In checking out the water lines under the kitchen sink, I'm seeing 2 unused lines. See picture below. The ones used are hot water, cold water to the faucet and then one line that goes to the dish washer. I think the dishwasher had an exit to one of the unused lines, but the dishwasher installer routed this to the garbage disposal. With a hot water loop, does anyone know how I would plumb the unused line?

 

If that line on the right is a direct run to the recirc pump then you just need to tie to the hot water line under that sink.. Odd its at the kitchen, but that may be the farthest and picks up all the other fixtures in home... Like master bath etc

 

I managed to find some old pictures, but not with anything hooked up. Previous owner says he can see the hot water loop on the left side, but wasn't sure what's on the right. The contractor said they only replaced the shut-off valves. From what I can see now, the dishwasher installer plumbed into the garbage disposal, instead of using the one that's capped. The previous owner thinks that's the Johnson tee. The one I'm uncertain about is the bottom right shut-off valve. We had a hot water dispenser in this location, but from what I can see from where it was moved, there is a tee on the cold-water valve.

 

What's towards the right of all that plumbing? Basically, where do you think that 1/2" capped/cut copper pipe go?
It's a strange setup - if it's just a recirc loop, I would expect it to basically be plumbed within the wall - no reason to jump out of the wall. So my thought is the 1/2" pipe that goes 'up' would be the recirc leg, but it's obviously just a big guess.

Is the kitchen the furthest away from the water heater? Or is there a bathroom thats further?

 

The previous owner thinks the one that's capped is where the dishwasher went to. It then goes to a Johnson tee. It's not being used as the new dishwasher was installed going to the garbage disposal as they said it can handle the load better. I agree that everything should probably be in the wall. My latest guess is that during the remodel, they changed something.

The kitchen isn't the furthest away.