Just bought a house and it has a grundfos timer/pump attached at the hot water tank. I have no hot water and the timer doesn't turn (as I've seen other timers do). Is it supposed to turn so that the little levers determine when the water is heated and when its not? Need to understand how the unit works so I can figure out what's wrong.

Have you tried turning the temperature down. If so and still have problem shut breaker off, let cool completely and then drain the tank by connecting a water hose to it. Sediment tends to build up on the bottom. When finished disconnect hose, turn valve closed, let tank completely. Fill before turning breaker on.

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.

1) Check that plumbing is correct:
http://waterheatertimer.org/Water-heater-recirculation-system.html

2) The timer has 2 choices: thermostat operation or timed operation.
http://waterheatertimer.org/images/IMG_9325-grundfos-timer-800.jpg
http://waterheatertimer.org/How-to-set-timers.html

3) Add comment and say what you discover

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

Pump can be bad or clogged with debris loosened when pipes were moved.
Check installation, and check if crossover valve is installed correctly
Check if single-handled faucets are good
http://waterheatertimer.org/Water-heater-recirculation-system.html
http://waterheatertimer.org/Crossover.html

Gene

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

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 sounds like thermostatic operation is not working.
I cannot offer specific repair, but can offer resources

1) Grundfos service options and warranty information + local distributor of parts and service center finder:
http://www.grundfos.us/web/homeus.nsf/Webopslag/OMAT-5S7J7X

2) Terminal strip and capacitor replacement does not show UP1510SU
http://www.us.grundfos.com/Web/Download.nsf/Pages/F3A9576228BA79AF0825691A006D2D0F/$File/Luptl028.pdf

3) Open following link for recirculation system resources including some manuals, but I don't have your exact manual.
http://waterheatertimer.org/Water-heater-recirculation-system.html
I can see your product on following link
http://www.houseneeds.com/shop/plumbing/recirculators/waterrecirculatorindex.asp

4) Recirculation systems operate 2 ways: with thermostat or timer.
Thermostat is supposed to turn off circulation when water reaches 100 degrees approx.
Until thermostat is repaired, you can work around problem by moving slide switch to TIMER and set timer to run intermittently so temperature at faucet is moderated.

5) Adjust temperature at water heater
http://waterheatertimer.org/How-to-adjust-water-heater-temperature.html

Upvote the help.
And take advantage of fixya expert assistance live.
For a price, expert works with you while you work on timer or any do-it-yourself project.
Fixya is always less expensive than a service call.

I think you have a grundfos recirculation pump.
This is not a water heater timer.
For illustration of grundfos system, open link below.
http://waterheatertimer.org/Water-heater-recirculation-system.html
Recirculation system is electric, but it also causes gas water heater to run more.
Unplug grundfos for a couple months to see if gas bill goes down. Your system will revert to regular water heater.

Many things can cause high gas bill. Make inventory of gas-consuming appliances: dryer, oven, stove, heater, water heater. Then inventory how often these appliances are used. Each appliance has a label with BTU listed. Add up BTUs of all appliances and compare with BTUs shown on gas bill. Call gas company about how to cut back.
Gas water heaters can become inefficient. So can any gas appliance. Look at flame inside water heater when it turns on. If flame is yellow instead of clear blue, that indicates the water heater is inefficient, and burner needs to be cleaned, or heater needs replacement or maintenance.
Call plumber for assessment and then post a question on the Tank to double check anything plumber says:
http://www.thetankatwaterheaterrescue.com/forums/forum3/

More information about circulation system:
Notice that illustrations show a pump located under the sink.
It sounds like you have same pump located at water heater.
Both types are same thing.
The purpose is to circulate hot water to your faucet so you don't have to wait for hot water when turning faucet ON. Instead, you have to wait for cold water.

The timer located on grundfos dial determines when pump turns ON.
Link above has illustration showing how to set timer pins using your thumb or ink pin or nail file (women know nail files, so I'm relating here).
To set timer, rotate dial until current time lines up with mark. The dial rotates as time passes and has to be reset after power outage.
If dial does not rotate, then timer is broken, but it sounds like pump is still working, and running full time which is wasteful.
Next, move the pins to set on-off times. Move pins inward, the pump is ON. Pins outward, pump is off.
For more exciting reading about the grundfos:
http://waterheatertimer.org/pdf/Grundfos-L-UP-TL-043-install-photos.pdf

Sounds like you have sediment built up in the pipes, and maybe the furthest faucet is the gathering place.
Take off each shut-off valve at furthest faucet and connect a water hose that flows into nearby toilet bowl.
You can buy garden-hose-to-1/2-pipe adapter at hardware.
Open water so it flushes the line into toilet bowl.
Then clean out valves and reassemble shut-offs and grundfos connection.
Remove faucet aerator and flush line up to faucet.
Install new aerator.

that pump is likely to be a hot water return pump not a booster pump. it sound like a large property so its likely the hot water system requires balancing to get the hot water to the extreme areas. If all the hot outlets have some form of isolation valve try closing all but the affected areas and see if hot water comes out. If so only open the closed outlets enough to give you reasonable flow. This hopefully will force the hot water to the affected areas.

pumps of this type will fail quickly without water. They are lubricated, and cooled by the fluid that runs through them.