Read some related questions here but none of them seemed to address my exact problem:
Bought a house this year that has the water heater in a closet near all the bathrooms. The only long run goes to the kitchen sink/dishwasher, where it will take 2+ minutes to get hot water, much to the wife's annoyance.
Investigated and found a circulation pump (Grundfos up 15-42f) in the crawlspace with a setup very similar to the picture below.
I'll skip the stories of the pump being clogged, burning out, dealing with home warranty, etc but go right to my questions:
What improvements can we make to the system? Right now the pump is either continuously on or off, only controlled by a switch annoyingly located in the crawlspace. My hopeful improvements would be:
- Move the switch into the closet with the water heater (luckily the pump and switch are located right under where the heater is).
- Add a timer so that it turns off at night (wife works from home so uses hot water throughout the day)
- Add isolation valves before and after the pump so that I can isolate it for repairs, etc.
- Get a pump that has either a demand sensor or a temp sensor, or both.
When the pump is off (such as at night or right now when it's broken), will the cold water supply feed back through the pump (ignoring the shown arrows)? I expect it does because when I went to drain the water heater and closed the cold valve right on the heater, water would still go into it - feeding from the cold street supply all the way backwards through the hot line (I think). I had to shut off water to the whole house at the street to get it drained.
- Would this partly explain why it takes so long for the kitchen to get hot water? It's pulling water both from the water heater and from the cold supply?
- Would this cause problems for the pump?
- Should we install another check valve between the pump and the cold supply line?
Thanks for the help.