Things have changed in recirc in 6 yrs. The best systems will be an "on demand" recirc, meaning it is controlled wirelessly with a motion sensor for bathrooms & a push button next to the kitchen sink. Grundfos makes a pretty good cross-over. Avoid Time or Temp controlled recirc.
Anyone install a hot water recirculating pump?
- Thread starter neblinc
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If the home has a basement or the plumbing layout allows a gravity recir is the simple and very effective solution
My last three homes have had this system.....it works, no moving parts, no service and cost of operation is insignificant. Instant hot water at every location in the home.
My last three homes have had this system.....it works, no moving parts, no service and cost of operation is insignificant. Instant hot water at every location in the home.
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58Yeoman
Well-known member
I installed a Laing system and have been using it in my previous house for years, and about 8 years in this house. I have the hot water to circulate 3 times a day, at our normal mealtimes. I have to reset the timer every once in a while, as our power goes out often.
It has the crossover valve under the kitchen sink, and the pump will pump hot water to the C-O valve, and push the cold water back into the cold line. During the times when the hot water is available, you will have to run the cold line just a bit to get rid of the hot water in it.
You can buy a 7 gallon electric water heater at Menard's online for $108, and put it under the sink, getting it's water supply from the hot side. By the time that you need more hot water, it should be there.
It has the crossover valve under the kitchen sink, and the pump will pump hot water to the C-O valve, and push the cold water back into the cold line. During the times when the hot water is available, you will have to run the cold line just a bit to get rid of the hot water in it.
You can buy a 7 gallon electric water heater at Menard's online for $108, and put it under the sink, getting it's water supply from the hot side. By the time that you need more hot water, it should be there.
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If the home has a basement or the plumbing layout allows a gravity recir is the simple and very effective solution
My last three homes have had this system.....it works, no moving parts, no service and cost of operation is insignificant. Instant hot water at every location in the home.
cheap, easy peasy.
JJohns3WG
Active member
I would recommend using a Grundfos pump you can pick up the basic ones for under a hundred bucks, just plug it into a digital timer another thirty bucks. Bulletproof system, you can set the timer for ten minutes before you normally take a shower. The digital timers can be had with multiple on - off each day, you could also add manual override switch.
Thanks guys.
I don't have a crawl space or basement, so running more water lines from just about anywhere to the HWH is going to be pretty involved.
I'm thinking about a simple pump with cross-over in at least one faucet. I picked up a Watts 500800 at Ace today, really sort of impulsively as it seems to be a tested system and they had it for the price I'd seen on Amazon - I wanted to be sure to reward them and not just go home and help put them out of business with my on-line shopping..
Now I want to find a semi-smart plug to which I can connect a remote switch and motion detectors. I'll put the motion detectors in the upstairs and master bathrooms and eventually a switch (with a dedicated crossover) at the kitchen sink which is on a separate branch.
I've found a few plugs that have integrated timers, turning off power to the plug after 10 minutes if they don't receive repeated "on" commands. The pump will be installed at the water heater and plugged into the wireless or smart outlet.
It really is a custom set up with a few specifics such as the auto-off, so I doubt I'll find a packaged plug and play system. I may have to go full smart and use IFTT or a similar app to coordinate them all.
As Jackfre said, simple time and temp controlled recirc systems don't offer the optimal balance of energy use and convenience.
The gravity systems are genius as they don't require mechanical components to function, but the cost of continually heating the water lines with no way to limit it to times of use is a major drawback. That system with a "smart" shutoff valve would be fantastic!
I don't have a crawl space or basement, so running more water lines from just about anywhere to the HWH is going to be pretty involved.
I'm thinking about a simple pump with cross-over in at least one faucet. I picked up a Watts 500800 at Ace today, really sort of impulsively as it seems to be a tested system and they had it for the price I'd seen on Amazon - I wanted to be sure to reward them and not just go home and help put them out of business with my on-line shopping..
Now I want to find a semi-smart plug to which I can connect a remote switch and motion detectors. I'll put the motion detectors in the upstairs and master bathrooms and eventually a switch (with a dedicated crossover) at the kitchen sink which is on a separate branch.
I've found a few plugs that have integrated timers, turning off power to the plug after 10 minutes if they don't receive repeated "on" commands. The pump will be installed at the water heater and plugged into the wireless or smart outlet.
It really is a custom set up with a few specifics such as the auto-off, so I doubt I'll find a packaged plug and play system. I may have to go full smart and use IFTT or a similar app to coordinate them all.
As Jackfre said, simple time and temp controlled recirc systems don't offer the optimal balance of energy use and convenience.
The gravity systems are genius as they don't require mechanical components to function, but the cost of continually heating the water lines with no way to limit it to times of use is a major drawback. That system with a "smart" shutoff valve would be fantastic!
When we remodeled, we had recirculating water put in. Grundfos pump. Actually, had two - one for each WH but they were plumbed in a hitch loop.
Used to run continuously - super expensive. Then, we added a timer that would run for a bit several times a day. Finally, used an X-10 setup so we turn it on a couple of minutes before we shower, laundry, etc. Then, turn it off. Edison bill is WAY smaller now. Sad that it took us so many years to figure it out.
Used to run continuously - super expensive. Then, we added a timer that would run for a bit several times a day. Finally, used an X-10 setup so we turn it on a couple of minutes before we shower, laundry, etc. Then, turn it off. Edison bill is WAY smaller now. Sad that it took us so many years to figure it out.
Thanks for sharing that. My Watts pump is not installed yet, and it's encouraging to hear that you've used the same Laing pump for 8 years. The fact that the crossover valve temp setting can be adjusted is a big plus!
I've thought about a tankless pump as a supplement, but we have a heat pump water heater. I can't get my brain to accept that installing a n additional, less efficient water heat is a better option than a fine-tuned recirc system.
Roger - can you explain the X-10 in a nutshell?
James-W
Well-known member
Personally, if it were me, I would just go with an under the sink "on demand" electric water heater. It is fairly easy to install, you get hot water for as long as you want, and it only runs when you need the hot water.
Tankless water heaters at the point of use certainly add convenience. The heat pump system I just installed has a uniform energy factor of 3.39. I'm happy with that and believe a recirc system will help maintain that energy efficiency while adding convenience and reducing water waste 
58Yeoman
Well-known member
I bought the 7 gallon heater from Menard's and installed it in my shop, which hasn't had hot water in the 10 years that I've lived here. (The shop isn't heater 24/7, so I had to use some ingenuity there). The circulating system in the house is super simple; has its' own timer and pump with a clock setting for on/off.
The electrician at work always installed the small electric water heaters under the sinks in the restrooms. He said it was so much easier and cheaper for the company.
Good luck with your system.
The electrician at work always installed the small electric water heaters under the sinks in the restrooms. He said it was so much easier and cheaper for the company.
Good luck with your system.
SILVERPLATE
Well-known member
We have a three year old home that has a instant hot water circulating pump located in a line from the hot water heater. It's awesome having instant hot water from any place in the house. It's just a very small electric in line pump.
With no way to run the dedicated line - The Watts system is as good as any -- remember the ones using the cold line naturally have to pump the hot back through that line ... so the cold line becomes warm as well. It's not my preferred way because I don't like to use the water from the tank for consumption.
Almost all of the systems use a temp controller even with a timer -- the pump is never running all the time. Running all the time would be very wasteful. With success using the lang pump that's been my preferred pump -- but, I don't think it matters as much today.
I do the dedicated line ... in the past w/o dimmers on a main bath light you could use that feed for the pump ... I still have that system for a far flung bath at the beach. Turning on the light activates the pump.
Almost all of the systems use a temp controller even with a timer -- the pump is never running all the time. Running all the time would be very wasteful. With success using the lang pump that's been my preferred pump -- but, I don't think it matters as much today.
I do the dedicated line ... in the past w/o dimmers on a main bath light you could use that feed for the pump ... I still have that system for a far flung bath at the beach. Turning on the light activates the pump.
Any idea how the pump is set to operate? They don't need much energy to run. In fact, manufactureres will say it only costs a few dollars per year to have hot water at every tap. What they don't tell you is that the (typically cold) water they send back to the heater is going to make your water heater work all day long. Water heaters make up about 20% of the household energy usage - and that number is based on the cost of heating the water actually used. The recirc pump is great in that it prevents wasted water running down the drain waiting for hot water to arrive to the faucet, but on a cost analysis alone, it is preferable to waste water rather than energy.
The ideal many are looking for is a system that adds convenience (instant hot water), reduces water waste (cold water in the hot line is returned to the heater rather than going to sewage), and keeps energy use to a minimum (only heat the water in the lines when the lines are actually being used).
That's where creativity comes in: using timers or other devices to run the recirc pump as little as necessary while delivering hot water to the taps when we need it.
justsam
Well-known member
I have a tankless system in a 4500 sq ft home, and a recirc. pump. We used to use small RF transmitters (Skylink) to operate pump. With more home automation we now use a WEMO smart plug, controlled by Amazon (Alexa) DOTS. The same automation controls lights, blinds,, fireplace etc. You just need to remember to ask Alexa to "turn on hot water", before need.
That's clever! Thanks for sharing
I'm actually trying to figure out what's the best solution for my new place. Have been told that doing a "home run" PEX system reduces the problem as the lines are direct and don't hold the same large amount of water. My lengths are short as well ... but ..... I'm unsure and will most likely run the dedicated return just in case.
Ideally -- if a one cycle system was available ... and everybody remembered to use it .. that would be great. Knowing myself -- that's not going to work ... and what about guests?
Think maybe having one of those occupancy sensors would be a good compromise. One could even retrofit them into a Laing type pump with the temp sensor and no timer.
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sberry
Banned
They have a 2.5 also. Super simple, low power demands.
They also make 3/8 pex for hot home runs for this too.
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6768rogues
Banned
If you have access to install a return pipe, go for it. Recirculating systems are commonly used in commercial projects and are required by code in commercial uses if the water heater is over a stated distance from the outlet. They work great, why not do it?
58Yeoman
Well-known member
And a 4 gallon. When I went to Menard's, they didn't have them in the store. Online, you could get any of them delivered to your home. The 4 and 7 were exactly the same price, so I went with the 7 for the shop.
sberry
Banned
A shower or laundry isnt a problem. The main reason is for repeated hand washing. In my office, kitchen and upstairs bathroom is about 4 ft of line and I only have about 2 ft of 3/4 on it, went to 1/2 which helps a lot. My main shop sink has about 20 ft of line, it takes 20 seconds or so. The water use is minor concern and the hot is really rather minor in the grand scheme, laundry is the big deal.
I use hot pressure washer frequently. 50 cents an hour on cold, 10$ an hour hot. Not cheap but like compressed air,,, lot of work fast and can do so many jobs that would be so tedius otherwise. One of the reasons I fix a starter the other day,,, was super filthy, 5 minute clean, 30 minute repair, 91$ plus tax I save and didnt have to go to the store.
I use hot pressure washer frequently. 50 cents an hour on cold, 10$ an hour hot. Not cheap but like compressed air,,, lot of work fast and can do so many jobs that would be so tedius otherwise. One of the reasons I fix a starter the other day,,, was super filthy, 5 minute clean, 30 minute repair, 91$ plus tax I save and didnt have to go to the store.
You could always put a solenoid on the return line just before the check valve. With a little knowledge you could get it working with just about anything that is smart. https://www.electricsolenoidvalves.com/3-4-110v-ac-electric-brass-solenoid-valve/
sberry
Banned
Wish they would have had these stores when I did my first ones. What a pain in the azz all this was. I found used, fixed a couple. This one been in now for 25 years. I would have give up a hundred bucks at the time. I got full size gas on my office and have had the switch off on this one lately.
Got it on a shelf out of the way.
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I installed the Watts branded pump about 6 months ago. It's been great. I set to run 15 minutes then off for 15 minutes (15 is the smallest interval). I don't mind a little bit of warm water in the cold water line. I rarely ever specifically want cold water.
Having a recirc pump on our hot water heater was the main reason why I got involved with Z Wave devices about 10 years ago. I have updated since then, but the system works great.
We started out with a simple 'controller' and a couple of modules like these for $70
Plug the appliance module into a wall outlet and then plug the recirc pump into the module. The controller worked two ways. You could manually push a button to turn it on or off, or you could set up a program to turn it on and off automatically, whenever you wanted - like first thing in the morning, lunchtime, etc
I started adding smaller remotes for each bathroom, kitchen, etc. They only had basic on/off capabilities
Then, since I had a home server, I bought some software (Think Essentials) that would automate a lot of the things and finally upgraded to HomeSeer3 a couple of years ago which really lets you do a lot of stuff. Like it can detect when the pump has been turned on and automatically shut it off after 3 or 4 minutes. Adding some Amazon Alexas does away with remote switches. We can just say 'turn on water heater' and it does it.
A lot of options are available, just depends on how complex and how much money you want to spend
We started out with a simple 'controller' and a couple of modules like these for $70
Plug the appliance module into a wall outlet and then plug the recirc pump into the module. The controller worked two ways. You could manually push a button to turn it on or off, or you could set up a program to turn it on and off automatically, whenever you wanted - like first thing in the morning, lunchtime, etc
I started adding smaller remotes for each bathroom, kitchen, etc. They only had basic on/off capabilities
Then, since I had a home server, I bought some software (Think Essentials) that would automate a lot of the things and finally upgraded to HomeSeer3 a couple of years ago which really lets you do a lot of stuff. Like it can detect when the pump has been turned on and automatically shut it off after 3 or 4 minutes. Adding some Amazon Alexas does away with remote switches. We can just say 'turn on water heater' and it does it.
A lot of options are available, just depends on how complex and how much money you want to spend
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Z wave occupancy sensor would be interesting.
Taco makes a learning system that people say works well.
Most people have a pattern -- so how much is a few hours here and there actually costing to heat the water that eventually cools agin in the pipes .. not very much.
My Buderus CI boiler controller (eccomatic) has a built in program for the recirculation pump - that's nice because you can program for all 7 days and with one button you can override when guests are around. The indirect had a dedicated return for the pump as well. We have gone backward at bit
Taco makes a learning system that people say works well.
Most people have a pattern -- so how much is a few hours here and there actually costing to heat the water that eventually cools agin in the pipes .. not very much.
My Buderus CI boiler controller (eccomatic) has a built in program for the recirculation pump - that's nice because you can program for all 7 days and with one button you can override when guests are around. The indirect had a dedicated return for the pump as well. We have gone backward at bit
Innovate1
Well-known member
I put a return line in about 15 years ago when building the current house. Put a small pump by the water heater. Think it is grunfos but several companies make them. It is just a general purpose pump - nothing specific for controlling it in this application. Used a "Relay in a box" to provide low voltage control and a push button in the bathroom to run it for 45 seconds when pushed. We use it mainly when showering. Push the button when you are getting ready to shower and it is hot by the time you get in. Low SAF at first because it was different but everyone is happy with it now.
Keeping the pipes continually warm has a lot of heat loss and we avoid that with a simple system.
Keeping the pipes continually warm has a lot of heat loss and we avoid that with a simple system.
What stops it after 45 seconds?
The only thing to be mindful of as far as the pumps -- need one for potable water. Many of the pumps are not.
Innovate1
Well-known member
I programmed an Arduino microcontroller board for that and a few other things.
redmondjp
Well-known member
And for those who don't have this skillset, you can use a time-delay relay to accomplish the same thing. There are several types available.
58Yeoman
Well-known member
redmondjp
Well-known member
I've been using a 4-gallon version under my kitchen sink for the past 9 years now - I'll move up to the 7-gallon unit when I replace it. It runs just that sink and the dishwasher. In our master bath, I have another 4-gallon tank inside the vanity that feeds the two sinks. I love having instant hot water for hand-washing.
We have a tankless gas unit for the rest of the house, but it can only run one item at a time (person in the shower gets a cold water sandwich if somebody else turns on the hot water at the same time).
JRC3
Well-known member
^
Yep. If most of the waste and usage is something like the kitchen sink, I have a point-of-use under my kitchen sink. I love it. https://www.lowes.com/pd/American-W...tt-Point-of-Use-Electric-Water-Heater/3029167
Before it runs out the tankless has already started feeding it.
Yep. If most of the waste and usage is something like the kitchen sink, I have a point-of-use under my kitchen sink. I love it. https://www.lowes.com/pd/American-W...tt-Point-of-Use-Electric-Water-Heater/3029167
Before it runs out the tankless has already started feeding it.
SILVERPLATE
Well-known member
Runs continuously, plugs into wall socket. Been working just fine for four years now. My builder installs one in ever home he builds.
My recirc pump has a thermostat that clips onto the incoming water pipe. Even when we were using just the timer, when the water got hot enough, it would shut off the pump
I would think that anyone running a recirc pump 24/7 365 that does not have this or something similar - I think it would definitely be worth your while to look into one
Switch Modes: Switch open (OFF) at water temperature of approximately 105°F and above and switch closed (ON) at approximately 85°F and below.
here is an example I found
https://www.plumbingsupply.com/grundtimer.html
I would think that anyone running a recirc pump 24/7 365 that does not have this or something similar - I think it would definitely be worth your while to look into one
Switch Modes: Switch open (OFF) at water temperature of approximately 105°F and above and switch closed (ON) at approximately 85°F and below.
here is an example I found
https://www.plumbingsupply.com/grundtimer.html
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I would recheck the problem.
How much is "a lot" of water?
I am also on a well and thought about this "problem."
I checked and it was just over a gallon of water, into the vanity next to the shower, before I had hot water.
The cost of the pipe, pump, controls, install, etc. just wasn't worth it.
How much is "a lot" of water?
I am also on a well and thought about this "problem."
I checked and it was just over a gallon of water, into the vanity next to the shower, before I had hot water.
The cost of the pipe, pump, controls, install, etc. just wasn't worth it.
JRC3
Well-known member
Every start (not run time) of the well pump takes time from well pump's life. This was actually one item on my list of pros for a point of use heater.
kawamatt2
New member
I just finished up install of a ReadyTemp TL4000N setup. Its basically a Taco pump with a solenoid, temp sensor, and logic board. Pretty pricey but is all configured to allow setting the incoming water temp "turn off" point and ready to accept any sort of input "turn on" signal. I installed it under the sink in the master bath as this bathroom must be at the end of the branch and hot water takes at least 1:30 to arrive at vanity or shower.
I then installed a PCS Simpleworx fixture module trigger on the bathroom light switch and a PCS Simplworx receptacle receiver in the outlet box for the pump under the sink. When you turn on the light in the bathroom, pump the gets power and turns on until the temp set point is reached and shuts off. So long as the light switch is on the pump is attempting to keep the incoming hot line at the set temp (with some hysteresis built in).
Its working really well so far and a lot less wasted water waiting for hot. I imagine it will take a year or so for the system to break even on cost. I plan to watch the water bill and see if I can notice a difference.
I then installed a PCS Simpleworx fixture module trigger on the bathroom light switch and a PCS Simplworx receptacle receiver in the outlet box for the pump under the sink. When you turn on the light in the bathroom, pump the gets power and turns on until the temp set point is reached and shuts off. So long as the light switch is on the pump is attempting to keep the incoming hot line at the set temp (with some hysteresis built in).
Its working really well so far and a lot less wasted water waiting for hot. I imagine it will take a year or so for the system to break even on cost. I plan to watch the water bill and see if I can notice a difference.
Never heard of the Simpleworx modules, but they do look interesting
You did give me an idea though.. I have a bathroom or two where I am thinking about changing out the light switch to a Z wave switch - similar to what you did. I have been playing around with some real small battery powered motion detectors, but I prefer things to be hard wired
Oh, and welcome to Garage Journal (long time lurker?)
You did give me an idea though.. I have a bathroom or two where I am thinking about changing out the light switch to a Z wave switch - similar to what you did. I have been playing around with some real small battery powered motion detectors, but I prefer things to be hard wired
Oh, and welcome to Garage Journal
(long time lurker?)