On Demand Recirculation Pump

[LilyT]

My house has a recirculation pump installed at the water heater. There seems to be two dedicated return lines, one for kitchen and one for master bathroom. The master bathroom is above the kitchen on the 2nd floor, they are both on the same wing of the house.

Now on the opposite wing of the house, I'm converting garage into a bedroom and a bathroom. It's hard to add return line. I'd like to have a on-demand recirculation device installed under the new bathroom's vanity.

[Q]:
What is the device I need in that vanity cabinet?
Does this practice contaminate all the cold water lines in the house with recirculated warm water? Especially the cold lines in the kitchen where I get my drinking/cooking water from (including refrigerator water line)?

 

[Jamesplumbing06]

Grunfo makes a good thermostatic valve and timer pump. I have strong opinions of recirculated lines. So I keep them to me and just install the stuff. This one claims to only recurc up to 75 degrees then the valve in cabinet closes. So the cold water will have a milli second shot of 75 then drop back to your normal cold. Brand new and setup right. They are cool little devices for retro fit. It is better to run dedicated line back to pump. From furthest fixture. Any way you go. Insulate hot lines with good pipe insulation of you loose a lot of money. Check timer every time electric goes off or 3 months.

 

[Diehard]

Totally agree with you James.
Additionally...
Coming from a background, heavy into cross connection control, connecting a hot water line to my drinking water would force me to take my daily pills and brush my teeth with bottled water.
For those interested in the subject, just google why you shouldn't use hot tap water in cooking or any way that it would end up being ingested.

 

[LilyT]

Thanks, James and Diehard! Seems like it would be better off (safer) not to install recirc device at the remote fixture in retro-fit.

In my remodeling, my plumber used PEX instead of copper. I have seen people insulate copper pipes using black foam wrappers. Is there a similar one for insulating PEX line?

 

[LilyT]

Hi James, although I'm pretty much giving up on the idea of installing one, I'm still curious to know the model you mentioned above. Do you have the model# of the Grunfo product? Thanks!

 

[Jamesplumbing06]

Insulation is same as copper pipe.
Grundfos GRU-595916 595916 https://www.amazon.com/dp/B000JG81AQ/?tag=skimlinks_replacement-20

 

[Jamesplumbing06]

Recirc lines are very comfortable. It’s soooo nice to just turn on hot water and it be hot. But electric bill goes up or gas. And you figure out water is cheaper than those other 2 ( gas, electric) and you finally turn off pump and just wait for cold water to flush out lol.

 

[Mikey]

I use a Watts recirculator with two loops; easy to install, like it a lot. The pump itself uses negligible electricity, hard to tell about the WH energy use. Insulating all the HW pipes carefully made a huge difference.

 

[SHEPLMBR]

I use a Watts recirculator with two loops; easy to install, like it a lot. The pump itself uses negligible electricity, hard to tell about the WH energy use. Insulating all the HW pipes carefully made a huge difference.

Surprisingly Watts is made by Grundfos. Just their name on it.

 

[LilyT]

Hi Mikey, I'm curious why you say "easy to install"? I feel adding a return line to my existing house is the most challenging (disruptive) part. Is your case very different - the path to your water heater is easy to access (wide open)?

 

[LilyT]

Thanks, James, for listing the model#! Because I already have a recirc pump installed at the WH, I think I need to buy only the valve to install at the furthest faucet.

 

[Mikey]

Hi Mikey, I'm curious why you say "easy to install"? I feel adding a return line to my existing house is the most challenging (disruptive) part. Is your case very different - the path to your water heater is easy to access (wide open)?

I cheated - installed it "stock", using the cold-water line for the return. One of the two loops does, however, have easy access so that running a PEX return line will be easy, and I plan on doing that as part of a remodel. The other loop is darn near impossible.

The Watts model is "Watts 500800 Instant Hot Water Recirculating System with Built-In Timer", about $200 from you-know-where. I bought a second valve assembly (Watts Premier 0955801 Sensor Valve Kit) ($62) for the second loop.