Whole Home Hot Water Circulation

[mcbane]

Since there are multiple points of potential hot water use, where is single point measurement recommended?

Thats a tough problem. I only have one far away bathroom so only one place to sense temperature. And if you want multiple sensing locations you would need to buy a thermostatic switch for each location that has a loop back plumbed in.

 

[dcg9381]

Does anyone have any first hand experience with these? Do you like the hot water circulation system? Have you had any issues with the system? If so, which part?

Thank you.

I don't know anything about retrofitting, but it sounds like you're in luck with a basement.
I have a "whole house" re circulation system. We have Navien tankless (LPG) water heaters. These have internal pumps. Apparently they "learn" when hot water is in use and per-circulate internally. What I found as my plumber largely just threw them in there, is that they actually can recirculate on demand.

So each of our bathrooms has a "door bell" next to the bath/shower that I wired up - CAT6 wire, low voltage DC. You press that button and the hot water heater knows to start the re-circulation process.

For us, it's about water use - we're on rain water.. So we don't want to run lots of gallons of cold water out of the showers.

 

[2Fast]

I don't know anything about retrofitting, but it sounds like you're in luck with a basement.
I have a "whole house" re circulation system. We have Navien tankless (LPG) water heaters. These have internal pumps. Apparently they "learn" when hot water is in use and per-circulate internally. What I found as my plumber largely just threw them in there, is that they actually can recirculate on demand.

So each of our bathrooms has a "door bell" next to the bath/shower that I wired up - CAT6 wire, low voltage DC. You press that button and the hot water heater knows to start the re-circulation process.

For us, it's about water use - we're on rain water.. So we don't want to run lots of gallons of cold water out of the showers.

If you have a Navien, there are a couple of youtube videos where you can use the 'hot button' (on demand) settings to control the recirc pump using Alexa or other Z-Wave/wireless type devices.

Did you need to manually change the setting 'fixture distance' to increase the run time of the pump to get the water temp up? (Check the IN water temp before the pump shuts off)

 

[dcg9381]

If you have a Navien, there are a couple of youtube videos where you can use the 'hot button' (on demand) settings to control the recirc pump using Alexa or other Z-Wave/wireless type devices.

You can, and I found one of those ways discussed on GJ, but if you do not actually have recirculation plumbing setup, all you are doing is pre-heating the water in the heater. Better than nothing.

Did you need to manually change the setting 'fixture distance' to increase the run time of the pump to get the water temp up? (Check the IN water temp before the pump shuts off)

I did. I had to monkey with it... My plumber was pretty worthless on anything outside of plumbing, which apparently includes configuring the water heater's settings. Thanks for the heads up.

 

[duneslider]

I'm planning to add a recirculation line to my house before I finish the basement. My garage sink is like 3 feet from the waterheaters so it is nearly instant hot water. The kids bathrooms are quite a distance from the water heaters and with the low flow faucets now days it takes a long time to get hot water to them. I would say minutes of running. I should time it.

I am also going to insulate the hot water pipes to help with it and I think running on a time or some other "smart" method will not add too much to energy costs.

 

[Fav Onefour]

I'm planning to add a recirculation line to my house before I finish the basement. My garage sink is like 3 feet from the waterheaters so it is nearly instant hot water. The kids bathrooms are quite a distance from the water heaters and with the low flow faucets now days it takes a long time to get hot water to them. I would say minutes of running. I should time it.

I am also going to insulate the hot water pipes to help with it and I think running on a time or some other "smart" method will not add too much to energy costs.

Commenting to the bold.
My wife found one of these fancy schmancy low flow shower heads. And I mean low flow. It is an early kickstarter version Nebia. I put that thing in the master bath which happens to be the furthest point from the water heater. (2nd floor, far corner) I have 3/4" supply line running all the way to the bath. Hot water is not used often in that room. Usually about two times a day. It took awhile to see hot water before the low flow shower swap. Now. . . the shower on it's own takes a real chunk of time.

Let's just say that I have thought about the topic of adding a circ system for that bath.
I like a hot shower. The rest of the house is fine. In fact, the wet wall layout was planned well and works efficiently. It's just the master bath that takes so much time. It was slow to heat before changing the shower head. The low flow head really takes time. We run the sink hot faucet just to speed up the process. The master shower and bath is used less and less often because it just isn't convenient.

This discussion is interesting and helpful.

Low flow fixtures have their place I guess, but I'm having a hard time with this bathroom. Swapping the shower head is obvious, but I'd still be running water to get through the long 3/4" supply line. Everything in the bath takes time to warm. The supply runs between floor joists and tees off at each fixture set. Running an additional return for a circ system would take some real remodeling. On demand under the sink is possible, but the supply setup might not make it feasible to do the whole bath.

I'm not sure of a simple and efficient solution for the master bath in my situation.

 

[DGersic]

Commenting to the bold.
My wife found one of these fancy schmancy low flow shower heads. And I mean low flow. It is an early kickstarter version Nebia. I put that thing in the master bath which happens to be the furthest point from the water heater. (2nd floor, far corner) I have 3/4" supply line running all the way to the bath. Hot water is not used often in that room. Usually about two times a day. It took awhile to see hot water before the low flow shower swap. Now. . . the shower on it's own takes a real chunk of time.

Let's just say that I have thought about the topic of adding a circ system for that bath.
I like a hot shower. The rest of the house is fine. In fact, the wet wall layout was planned well and works efficiently. It's just the master bath that takes so much time. It was slow to heat before changing the shower head. The low flow head really takes time. We run the sink hot faucet just to speed up the process. The master shower and bath is used less and less often because it just isn't convenient.

This discussion is interesting and helpful.

Low flow fixtures have their place I guess, but I'm having a hard time with this bathroom. Swapping the shower head is obvious, but I'd still be running water to get through the long 3/4" supply line. Everything in the bath takes time to warm. The supply runs between floor joists and tees off at each fixture set. Running an additional return for a circ system would take some real remodeling. On demand under the sink is possible, but the supply setup might not make it feasible to do the whole bath.

I'm not sure of a simple and efficient solution for the master bath in my situation.

The recirc pump that pulls from the hot and pushes in to the cold may work for you in this setup.