I just bought a repo house which has a grundfos circulation pump u p 15 installed at the water heater. House built 2005 4260 sq. Feet. House has 4 showers only one of them gets hot water. All sinks get hot water. Also in the showers that dont get hot when you turn the knob over to the hot side the water pressure goes way down when you get it back over to the hot side pressure goes up. Do you think it is the pump or just the showers not being used very much maybe the water knobs in the shower need to be adjusted?

Last one I installed, I used a PIR sensor to control it, so that whenever someone walked towards the bathroom or kitchen, the pump will start up and run for 15 minutes. It really depends how often you use hot water - if only certain times of day, then it would be wasting power to run the pump, and heat loss from the pipes (unless very well insulated). If you have a regular pattern of use, then you could use a timer/programmer as you would on your normal hot water or heating. If your piping is plastic, then don't run pump continuously, as some plastic piping is not recommended for continuous circulation at normal hot water temperatures.

Replace crossover valve located under sink
http://waterheatertimer.org/Water-heater-recirculation-system.html
http://www.amazon.com/dp/B00128BIUU/?tag=waterheaterti-20

gene

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

At approximately $238.95 new, it pays to do a bit of troubleshooting.
Below are some sites that may help:

http://www.plumbersurplus.com/Brands/Grundfos/74

http://waterheatertimer.org/Water-heater-recirculation-system.html#Grundfos


There are no repair parts for these pumps, and nobody at Fixya has reported taking Grundfos apart and repairing it.

Sounds like 2 problems:
1) Crossover and 2) Setting timer
Recirculation system has check valve that stops backflow of water when pump is turned off.
When check valve is clogged with sediment, or has worn out, then cold water enters hot pipe or hot water enters cold pipe when faucet is turned on.
Take apart connection where grundfos connects to both hot and cold pipes, and clean with white vinegar or CLR.
http://waterheatertimer.org/Crossover.html
http://waterheatertimer.org/Water-heater-recirculation-system.html

Open following link for setting typical FM/1 analog timer module on Grundfos recirculation pump:
Your timer module may vary in appearance.
Slide switch selector might be located below timer dial.
http://waterheatertimer.org/images/IMG_9325-grundfos-timer-800.jpg

it's possible but not all that likely. The sump pump is pumping dirty water and the domestic water should be clean.

I have circulation system on my water heater.
First system gave out.
When taken apart, it was clogged with sediment and couldn't be cleaned.
Put sediment filter on line, and second circulation system works fine, and timer works fine too.
I haven't had timer problem, but have investigated timer motors running fast and slow.
My friend who re-winds big pump motors says homeowner timer motors are engineered for 60Hz.
As long as electric power is 60Hz (60 cycle AC), then motor will keep exact time.
Since your household current is 60Hz and other electro-mechanical timers run correctly, then it's likely timer motor has a flaw or has gone bad.
Grundfos water heater re-circulation pump and timer are sealed unit.
Grundfos manuals do not show parts list or repair steps:
http://waterheatertimer.org/Water-heater-recirculation-system.html#Grundfos
It's aggravating when expensive household timers like Malibu power packs and Grundfos pumps are not made to be repaired.

Grundfos is a sealed unit and not a repairable item.
The timer dial should turn.
And pins located around dial control ON-OFF functions as timer dial rotates.


Does the receptacle have power?
If receptacle has power, and Grundfos is not working, then it is broken.
Grundfos manuals for UP series pumps do not show breakdown or parts list of any kind.
http://www.us.grundfos.com/web/download.nsf/Pages

Bigger question:
Why don't you have hot water?
Is water heater functioning?
Water heater is a separate appliance from Grundfos pump.
Grundfos pump circulates hot water from tank into the lines so there is no waiting for hot water ... but hot water heater should still make hot water.
http://waterheatertimer.org/Water-heater-recirculation-system.html

Add a comment about water heater if that is also a problem.
You could have 2 problems, and water heater is main issue.

For do-it-yourself electric water heater repairs:
http://waterheatertimer.org/6DIY.html

Grundfos is a p. o. s. I have a new system cu 301 and I have had to get it repaired twice by Fogle Pump and Supply. These guys are real rip of artists in Washington State and should be reported to the BBB. Dont Use Fogle if you need a well

here you can find the solution http://www.plumbnation.co.uk/site/grundfos-upa-15-90-home-booster-pump/Grundfos%20UPA%20Technical%20Information.pdf

Do you have more than one zone? If so, it is difficult to tell if the circulator in question is actually running. A trick is to get a screwdriver and place the metal end on the front of the circ and the other on your ear. You will hear it if it is running. If you do hear it, is the circulator itself very hot to the touch? If it is, it may be burnt out, or the zone needs to be bled of air. Another doubtful, but possible, answer is that the circulator is installed backwards. There is an arrow on it and it should be aimed towards the flow of water.