Water Heaters, what is this connected to the water heater?

Wondering if you guys can help me define what this is connected to the water heater. Public water, well water for sprinkler system!

It’s a circulation pump. It’s to prevent the long wait for hot water at fixtures far away from the tank. It’s actually the same premise large hotels, office buildings, etc. use. Run a loop of hot water through the building so when it’s needed at a given fixture the wait is not long. They are often called “Taco Pumps”. I believe that is a brand name.

Looks a lot like a hot water recirculatory system, either for faster domestic water or for a radiant floor heating system.

For example:
On-Demand Hot Water Circulation Pumps (fasterhotwater.com)

If this is run 24/7, the cost to the owner can be large. You can recommend a system that turns off once hot, runs only on water use, or a demand-push system.

Common brands of smart systems are:

  • Metlund D’MAND
  • Taco Genie (licenses the patent of D’Mand).
  • Get Faster Hot Water
  • Chili Pepper Project (founder of D’Mand, just started up after expiry of non-compete with D’Mand https://chilipepperapp.com/ ).

Or, in this case, it may just be a dumb pump, in this case just a plain old Grunfos water cooled model.

Appears to be a Grundfos Circulation pump. 1/25 horsepower - Flow Range: 0- 17 GPM, Head Range: 0- 19.5-Feet - Motors: 2 Pole, Single Phase, 115-Volt
Likely radiant flooring.

Just curious, do circulator pumps typically get connected to the hot water heater drain port to keep the hot water circulating throughout the system?

As a dedicated return line the answer would be yes but this is not a typical installation.

Installing a pump on the hot water supply is the preferred professional installation method.

Morning, Robert. The flood pan is plumbed to the .floor drain. It had me wondering the same thing until I looked closer.

Thanks Martin,
I figured that this was probably one way to do it by removing the drain valve and installing the pump there according to your graphic. Looks like it makes sense because it’s returning the cooler water to the bottom of the tank.

Hey Robert. The way I was taught 30 years ago was to tap into the bottom of the hot water heater and run that line to the second floor. At the second floor of the house you would tie into the hot water riser. As the hot water would rise out of the water heater from the basement it would travel to the second floor and return back to the bottom of the water heater without the use of a pump. This thermal water motion works with the hot water expanding out of the top of the water heater. The only component that would be installed is a boiler drain to replace the drain spigot that was removed from the bottom of the water heater and a check valve.

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Yes! This works super well. I’ve seen several systems with FAILED pumps that still kept the pipes hot (in apartment buildings). The thermosiphon effect does all that’s needed. The same effect is used in passive solar, where the tank is above the collectors.

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