Point of Use Hot Water Heater Questions

[Alan Rutherford]

Hot water travels about 60 feet from the tank to our upstairs bathroom and it takes too long to get there. I'm thinking about installing a point-of-use heater with a mini-tank but don't know if it will do what I want. Can I install a 2.5 gallon POU heater in the hot water supply to the bathroom and expect both immediate hot water from the POU heater and a reasonably seamless switch to the hot water from the central HWH when it gets there? There's about a half gallon of water in 60 feet of 3/4-inch pipe. There is not currently a tub or shower in that bathroom (I took out the old clawfoot and have not replaced it) but there will be so I don't want to make the POU heater the only HW source.

Google couldn't find anything here on this subject newer than 2007 so I'm hoping for some more recent experience.

[Malcolm McLeod]

You might consider a small circulator pump? Install under a sink - it pulls water from the hot line and pushes it back into the cold line. Plug it into a timer control, and select the run times for when you want 'instant' hot water.

You'll need convenient access to power, but you'll need that anyway I guess, so the pump and plug might be cheaper and likely more compact that POU heater?

[Alan Rutherford]

I can't believe I'm saying this, but "cheaper" isn't a big consideration here as long as I'm not throwing money away or ending up with a disappointment. The hot water line is well-insulated but the cold is not, so there would be some efficiency lost with the recirculation. And considering the bathroom habits of my age group, prompt hot water would be nice 24 hours a day.

[Bill George]

I can't believe I'm saying this, but "cheaper" isn't a big consideration here as long as I'm not throwing money away or ending up with a disappointment. The hot water line is well-insulated but the cold is not, so there would be some efficiency lost with the recirculation. And considering the bathroom habits of my age group, prompt hot water would be nice 24 hours a day.

Run the circulating pump line back to the water heater via a PEX line you install. Let it run 24 / 7.
A point of use could be a small tank one well insulated plugged in 24/7.

[Edward Weber]

I have a circulator pump installed on top of the water heater. There is a temp sensing valve inder the sink (no power needed for valve).
https://www.homedepot.com/p/Watts-Hot-Water-Recirculating-System-with-Built-In-Timer-0955800/100426993
There are lots of setting options.
I'm in a rancher and from the heater the master bath is further than your run.
I wouldn't be without it.

[Bill Dufour]

How about a tankless?
The taco pump can have a push button switch at the sink to turn it on and run for two minutes or so.
Bill D

[Brian Elfert]

Why not run hot water from the main water heater into the POU water heater. You should have hot water from the main water heater before the PUO water heater is out of water.

[Alan Rutherford]

Why not run hot water from the main water heater into the POU water heater. You should have hot water from the main water heater before the PUO water heater is out of water.

That's what I'm considering. Trying to find out if it would work as well as I hope it would.

[Bill George]

That's what I'm considering. Trying to find out if it would work as well as I hope it would.
I had assumed that was going to be the case. Why on earth would you try to heat water from the cold water line when there is a hot water line already there?

[Edward Weber]

I think you might be over thinking it.
You have hot water, you just need to get it to where you need it.

A circulator pump keeps hot water on demand at the point where you install the valve. There is no need to wait for water to warm up, no waste, no extra tank, minimal plumbing skills, customizable timer, cheap to run

JMO

[Jerome Stanek]

I have a circulator pump installed on top of the water heater. There is a temp sensing valve inder the sink (no power needed for valve).
https://www.homedepot.com/p/Watts-Hot-Water-Recirculating-System-with-Built-In-Timer-0955800/100426993
There are lots of setting options.
I'm in a rancher and from the heater the master bath is further than your run.
I wouldn't be without it.

I have the same unit but after having it for a few weeks I installed a return line with a check valve in it. When I first installed it the cold water was warm untill fresh water flowed around.

[Alan Rutherford]

I think you might be over thinking it.
You have hot water, you just need to get it to where you need it.

A circulator pump keeps hot water on demand at the point where you install the valve. There is no need to wait for water to warm up, no waste, no extra tank, minimal plumbing skills, customizable timer, cheap to run

JMO
Maybe I should consider using a recirc pump vs. the POU heater, but I'm not there yet. I'd think the recirculating system could not fail to deliver the hot water. My concerns would be that either I have to run a return line or I return through the cold water line. If I do that, there will be times the cold water is much warmer than expected and that's a problem. If the system includes the kitchen it would also mean sometimes drinking water that has been through the hot water heater, which is not appealing.

The only complaints I can find online about the POU heater are possible short life of the system, which worries me. I can't find any indication of whether you have reasonably constant water temperature as you use the water in the POU tank and it is replaced first by cooler water from the hot water pipes and then hotter water fresh from the central HWH.

[Bill George]

The POU heater is going to require a 15 amp circuit just for the heater, most have 1400-1500 watt elements.

[Paul F Franklin]

So if you feed the POU tank from the hot water line, where is the cold water that's in the line going to go? If you only need a little hot water, it will be fine, but once the POU tank is empty, you'll have cold water again until the hot water arrives from the main tank, because the POU heater won't heat the water quickly. Might not be an issue for a tub, but not what you want for a shower.

The recirc setups will do what you want, but they have downsides too. If you don't run a return line, you'll have hot/warmish water from the cold faucet for a while when first turned on. And those systems do waste energy because you will end up heating more water than you would otherwise. This can be minimized by using a pushbutton to activate them rather than letting them run 24/7 or putting them on a timer. But then you have to wait a bit after pushing the button before the hot water arrives. But at least the water isn't just running down the drain while you are waiting. And face it, most time you have a minute or two in the lav before you are ready to shower or wash your hands.

[Malcolm McLeod]

I have a circulator pump installed on top of the water heater. There is a temp sensing valve inder the sink (no power needed for valve).
https://www.homedepot.com/p/Watts-Hot-Water-Recirculating-System-with-Built-In-Timer-0955800/100426993
There are lots of setting options.
I'm in a rancher and from the heater the master bath is further than your run.
I wouldn't be without it.

Interesting rig. As I read it, seems pump can run some or all the time, but crossover valve only opens when hot water supply at install point (sink?) is <95F. That should reduce heat lost in the cold line (if used as return).

I've had (or have now) 2 systems; both just pumped on timer, but Mr. Rutherford's water usage patterns may require another solution.

[Alex Zeller]

What options do you have? Can you run a new return line for a circulator pump without a lot of work? I personally would not send hot water back down the cold water line. I don't know about other people but I like my cold water to be cold. Also you may find that your shower is now too hot until cold water flushes all the hot water out of the line. Can you run a new circuit? If so a tankless on demand heater would be your best option. If the heater can't heat up cold water as you use it you are going to have a hot shower that turns cold before to gets hot again as the slug of cold water between the storage tank and the POU heater makes it's way up to the bathroom. Since it's an upstairs bathroom I would think that your options are limited.

[Bill George]

o if you feed the POU tank from the hot water line, where is the cold water that's in the line going to go? If you only need a little hot water, it will be fine, but once the POU tank is empty, you'll have cold water again until the hot water arrives from the main tank, because the POU heater won't heat the water quickly. Might not be an issue for a tub, but not what you want for a shower.

The cold water line IN on the POU water heater connects to the existing Hot water line. The output connects to the hot water faucet. The 2 or 3 gallons of water in the POU tank should be enough until the existing hot water arrives.

[Paul F Franklin]

o if you feed the POU tank from the hot water line, where is the cold water that's in the line going to go? If you only need a little hot water, it will be fine, but once the POU tank is empty, you'll have cold water again until the hot water arrives from the main tank, because the POU heater won't heat the water quickly. Might not be an issue for a tub, but not what you want for a shower.

The cold water line IN on the POU water heater connects to the existing Hot water line. The output connects to the hot water faucet. The 2 or 3 gallons of water in the POU tank should be enough until the existing hot water arrives.

For the sink, maybe, but for a shower you're going to have 2 gallons of hot, then 2 or so gallons of cold (that was in the hot water line between the big heater and the POU) then hot again. Not good for a shower.

[Jason Roehl]

For the sink, maybe, but for a shower you're going to have 2 gallons of hot, then 2 or so gallons of cold (that was in the hot water line between the big heater and the POU) then hot again. Not good for a shower.

He already mentioned that it’s 60’ of 3/4” pipe. There’s about 0.025 gal/ft at that size, so just over a gallon. It’ll blend in with the hot water in the POU tank as he uses it. Most people have their water heaters set high enough that they have to blend some cold in with the hot for their showers anyway, so the usage from the POU heater will be slow enough that the incoming slug of room-temperature water from the main water heater shouldn’t draw down the temperature of the POU heater much.

[Jerome Stanek]

I think you might be over thinking it.
You have hot water, you just need to get it to where you need it.

A circulator pump keeps hot water on demand at the point where you install the valve. There is no need to wait for water to warm up, no waste, no extra tank, minimal plumbing skills, customizable timer, cheap to run

JMO

That is almost true but the advantage is where you put the valve. I put mine on the last sink inline and all the other sinks and tub shower have hat water almost instantly. There is a timer so you can set it to shut off the hot when it is not needed like if no one is home during the day or late at night it sets in 15 min increments. I have not notice a increarse in my gas bill since I installed it. and you do get the advantage of more hot water as the pipes are always full so you use less water.

[Bill George]

For the sink, maybe, but for a shower you're going to have 2 gallons of hot, then 2 or so gallons of cold (that was in the hot water line between the big heater and the POU) then hot again. Not good for a shower.

But your not using straight 140 degree hot water when you shower, its tempered with the cold water.

[roger wiegand]

A temperature sensing (vs flow sensing) on demand heater is a good option in this situation if you have the electrical capacity readily available. A circulating pump that runs continuously is very wasteful of power, a little for the pump a lot for the hot water heating (and more if you're radiating extra heat inside the house during AC seasons). A circulating pump with a switch at the POU (with an automatic shutoff so it doesn't keep running) is also a good choice.

[Bill George]

Those circulating pumps are very small, very little current draw and both lines are or should be insulated so little or no heat gain to the house. A on demand water heater costs $1200 plus and then the huge 230 volt service to run it makes it not practical. The little 115 volt point of use heater ($200-$300) in series with the existing hot water line only heats and holds 2 or 3 gallons of water in a well insulated tank.

This pump uses 10 watts > https://www.supplyhouse.com/Goulds-Pumps-60A0G1007-E1-BCTVNNNN-01-Circulating-Pump-w-Adjustable-Speed-1-2-Threaded

Installing> https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Goulds-Pumps-60A0G1007-Install-Instructions.pdf

[Perry Hilbert Jr]

Because of the way our house was built, the hot water travels 40 feet to one end and then up stairs and 40 ft back to the master bathroom. So the hot water to the master bathrooom takes a long time. However, there are several hot water using things along the way. So in the morning, I run the dishwasher and maybe a load of laundry, about the time Mrs. gets up to shower for work. Just that gets the hot water half way through the system before she gets to the shower. We use the hot water side of the master bathroom sinks to start washing, shaving etc., that also gets the hot water closer.

[Bill George]

Because of the way our house was built, the hot water travels 40 feet to one end and then up stairs and 40 ft back to the master bathroom. So the hot water to the master bathroom takes a long time. However, there are several hot water using things along the way. So in the morning, I run the dishwasher and maybe a load of laundry, about the time Mrs. gets up to shower for work. Just that gets the hot water half way through the system before she gets to the shower. We use the hot water side of the master bathroom sinks to start washing, shaving etc., that also gets the hot water closer.

Put in a pump, see the instruction manual I linked too above.

[Jack Frederick]

Are you able to install a recirc line? Taht would be the hot set-up. I just don’t care for the pump back into the cold line for reasons noted. Grundfos makes a nice set-up for recirc with the timer mounted on the pump. It seems a shame to waste the energy by running it 24/7. The house we just sold had a wireless control on the Rinnai water heater. I had motion sensors up in the corner of the bathroom ceilings and a push button mounted up under the cabinet next to the kitchen sink. When entering the bathroom the pump made and in a few seconds I had hot water. The key is to have a strong wireless signal. If you have wonky wireless it is a pitn. It worked well in our case not wasting water, energy or time.

[Edward Weber]

I've been using one, like the one I linked to, for 10 years, no issues what so ever.
The claim about hot water on the cold side is a bit overblown IMO.
Yes you do get lukewarm water for a bit on the cold side but the entire point of the product is to get hot water to that point. If you want ice cold water in the bath, you may need another solution.

[Stephen Tashiro]

The POU heater is going to require a 15 amp circuit just for the heater, most have 1400-1500 watt elements.

Do the tankless kind of electric water heaters only require 15 amps? I thought they usually have a higher peak amp draw.

[Bill George]

Do the tankless kind of electric water heaters only require 15 amps? I thought they usually have a higher peak amp draw.

This is a small point of use with a 2 or 3 gallon tank that's all. Not those whole house ones.

[Alan Rutherford]

He already mentioned that it’s 60’ of 3/4” pipe. There’s about 0.025 gal/ft at that size, so just over a gallon. It’ll blend in with the hot water in the POU tank as he uses it. Most people have their water heaters set high enough that they have to blend some cold in with the hot for their showers anyway, so the usage from the POU heater will be slow enough that the incoming slug of room-temperature water from the main water heater shouldn’t draw down the temperature of the POU heater much.


That's what I was trying to confirm. However, I'm not hearing a lot of love for POU heaters and I'll consider a recirculating pump. Thanks for all the input.

[Brian Elfert]

I have read stories of people who had their cost to heat water skyrocket when they put in a recirculating pump. The pipes will tend to radiate some of the heat from the water as it circulates so the water heater has to heat more often. A common thing is to put a timer on the pump to run only during times of day when hot water is commonly used. I don't know how common it is to have bills increase when recirculation is added.

[Bill George]

I have read stories of people who had their cost to heat water skyrocket when they put in a recirculating pump. The pipes will tend to radiate some of the heat from the water as it circulates so the water heater has to heat more often. A common thing is to put a timer on the pump to run only during times of day when hot water is commonly used. I don't know how common it is to have bills increase when recirculation is added.

Not if you do the correct way, Insulate the pipes.

[Jerome Stanek]

My wife could not get the concept of a on demand water heater she thought that it would give her hot water right away at the faucet. I had to explain it to her that it would just be like what we have without a tank. She wanted instant hot water so I got the ciculating pump and put in a return line.

[Alex Zeller]

Adding a return line in a two story house with insulation probably is not an easy option in an existing house. When I built my house I purposely made a chase that I can access from each floor for both water and electrical. I plumbed a pump on the domestic hot water line with a return line set up on a timer. It's connected to a towel heater and I have it set up on a timer so it'll come on a little before the wife was ready to take a shower. It also provided hot water much quicker to the shower and faucets in the master bath. The towel heater also heats up the bathroom as well (plus it has radiant heat in the floors).

[Dave Sabo]

I've been using one, like the one I linked to, for 10 years, no issues what so ever.
The claim about hot water on the cold side is a bit overblown IMO.
Yes you do get lukewarm water for a bit on the cold side but the entire point of the product is to get hot water to that point. If you want ice cold water in the bath, you may need another solution.

You’re missing the point entirely.

That lukewarm water stays in your cold water line until it’s expelled. The pumps don’t get tied in at a tub or a shower, they’re at a faucet. And not everyone likes or will tolerate warm water for brushing their teeth or filling a cup to drink. Depending on the particular setup that lukewarm water could last several minutes.

So, you’re trading fast / instant hot water access for longer wait time for cold water and the wasting of the water down the drain while you are wait8mg on that cold water to arrive.




Not if you do the correct way, Insulate the pipes.

Sure , but how practical is that when those pipes are inside finished walls , ceilings and stairwells ?

Answer: Not at all.

[roger wiegand]

Not if you do the correct way, Insulate the pipes.

Tearing walls and finished ceilings open to insulate the pipes gets pretty expensive pretty fast. I'd tolerate the wait for hot water before taking that on.

[Bill George]

Tearing walls and finished ceilings open to insulate the pipes gets pretty expensive pretty fast. I'd tolerate the wait for hot water before taking that on.

Well the OP has been given the only two choices I know of to fix his problem, maybe there are others but its either one of those or live with it. BTW you don't need to "tear apart walls" bore a hole and pump the space full of Insulation, exposed just add the pipe insulation.

[Edward Weber]

You’re missing the point entirely.

That lukewarm water stays in your cold water line until it’s expelled. The pumps don’t get tied in at a tub or a shower, they’re at a faucet. And not everyone likes or will tolerate warm water for brushing their teeth or filling a cup to drink. Depending on the particular setup that lukewarm water could last several minutes.

So, you’re trading fast / instant hot water access for longer wait time for cold water and the wasting of the water down the drain while you are wait8mg on that cold water to arrive.





Sure , but how practical is that when those pipes are inside finished walls , ceilings and stairwells ?

Answer: Not at all.
With respect, I'm not missing the point, I own one and I'm perfectly happy with it.
I offered it up as an easy solution to the OP's issue.
I also stated it might not be right for him.

[Dave Sabo]

Well the OP has been given the only two choices I know of to fix his problem, maybe there are others but its either one of those or live with it. BTW you don't need to "tear apart walls" bore a hole and pump the space full of Insulation, exposed just add the pipe insulation.


:rolleyes: that's only slightly more practical. But still not a truly viable option.

And you just call around to a couple if insulators and ask them how excited about that type of project they are, and let us know. Then ask the spouse how receptive they are to repainting all the rooms that the patches went into. Most likely it's the entire house. If they're OK with that, call around to the drywallers (or plasterers) and ask them about taking on that type of patching job and get back to us. If you find one, be sure to check in person examples of their work and tell us if you found it acceptable.



With respect, I'm not missing the point, I own one and I'm perfectly happy with it.
I offered it up as an easy solution to the OP's issue.
I also stated it might not be right for him.

You're perfectly happy with it and mentioned the bathtub, but you totally ignored the drawback of warm water at the faucet where many people actually like cold water, and where the circ valve would be loated. It'd be kinda obvious that one wouldn't need any type of solution if they liked cold water for their shower or tub.

Hence, me saying you missed the point of warm water in the cold line not being overblown.

[Bill George]

:rolleyes: that's only slightly more practical. But still not a truly viable option.

And you just call around to a couple if insulators and ask them how excited about that type of project they are, and let us know. Then ask the spouse how receptive they are to repainting all the rooms that the patches went into. Most likely it's the entire house. If they're OK with that, call around to the drywallers (or plasterers) and ask them about taking on that type of patching job and get back to us. If you find one, be sure to check in person examples of their work and tell us if you found it acceptable.

Really? That would be a DIY job in this house. How many wall pipe chases do you have in your house, I have three and spray can foam would be one solution. The rest are exposed in the basement. So what would You do to Solve the OPs problem? PS they have spray foam in 20 lb cylinders.

[Edward Weber]

:rolleyes: that's only slightly more practical. But still not a truly viable option.

And you just call around to a couple if insulators and ask them how excited about that type of project they are, and let us know. Then ask the spouse how receptive they are to repainting all the rooms that the patches went into. Most likely it's the entire house. If they're OK with that, call around to the drywallers (or plasterers) and ask them about taking on that type of patching job and get back to us. If you find one, be sure to check in person examples of their work and tell us if you found it acceptable.




You're perfectly happy with it and mentioned the bathtub, but you totally ignored the drawback of warm water at the faucet where many people actually like cold water, and where the circ valve would be loated. It'd be kinda obvious that one wouldn't need any type of solution if they liked cold water for their shower or tub.

Hence, me saying you missed the point of warm water in the cold line not being overblown.

What I said
From earlier post;
"I've been using one, like the one I linked to, for 10 years, no issues what so ever.
The claim about hot water on the cold side is a bit overblown IMO.
Yes you do get lukewarm water for a bit on the cold side but the entire point of the product is to get hot water to that point. If you want ice cold water in the bath, you may need another solution. "

Bath, is short for bathroom, just like master, is short for master bedroom.

Let it go

[Dave Sabo]

What I said
From earlier post;
"I've been using one, like the one I linked to, for 10 years, no issues what so ever.
The claim about hot water on the cold side is a bit overblown IMO.
Yes you do get lukewarm water for a bit on the cold side but the entire point of the product is to get hot water to that point. If you want ice cold water in the bath, you may need another solution. "

Bath, is short for bathroom, just like master, is short for master bedroom.

Let it go


Repeating yourself (or having one) doesn't make it any more true.

The cold water wait time IS a decision point that many people will not find "overblown". For you it may be - for others , not so much. Sure, the point of a recirc. pump is to have instant or faster hot water delivery throughout the house, but there are tradeoffs of using that or using that over another method.

Is the cost of such a system "overblown"?

What about the added energy and water usage ?

Really depends on your perspective and what you find important, but all of those things go into a decision at the end of the day.


Our homes would be full neat-o , gee wiz, super cool gizmos / tech / features / higher quality materials materials, features, and conveniences except for those pesky details that are "overblown" according to some people.

[Bill George]

Running Hot side water to make it hot for your use, your paying to heat that wasted water. Cold water side, just paying for the water. I would run a PEX line back to the Water Heater and then insulate both lines as I described above.

[Jerome Stanek]

Repeating yourself (or having one) doesn't make it any more true.

The cold water wait time IS a decision point that many people will not find "overblown". For you it may be - for others , not so much. Sure, the point of a recirc. pump is to have instant or faster hot water delivery throughout the house, but there are tradeoffs of using that or using that over another method.

Is the cost of such a system "overblown"?

What about the added energy and water usage ?

Really depends on your perspective and what you find important, but all of those things go into a decision at the end of the day.


Our homes would be full neat-o , gee wiz, super cool gizmos / tech / features / higher quality materials materials, features, and conveniences except for those pesky details that are "overblown" according to some people.

The water usage is a lot less and the energy usage is almost the same.

[Alan Lightstone]

We installed a POU heater for our kitchen sink as the run was way too long from our tankless system, and it took a long time to get hot water there. It works very well, no issues. By the time that tank has exhausted its hot water, the tankless hot water reaches there.

Of course, that doesn't help our master bathroom or the den bathroom that are farther away and 30 feet up, but we couldn't run circulating pipe for that.

[Mike Henderson]

Our situation was that the hot water heater was on one side of our house and our master bath was on the other side of the house. Took forever to get hot water.

I had the plumber split the system and we installed a gas tankless on the side of the house where the master bath is. It's not immediate hot water, but fairly quick.

Mike

[Jerome Stanek]

Our situation was that the hot water heater was on one side of our house and our master bath was on the other side of the house. Took forever to get hot water.

I had the plumber split the system and we installed a gas tankless on the side of the house where the master bath is. It's not immediate hot water, but fairly quick.

Mike

That is why I installed the circulating pump have hot water in abou 3 seconds or less at the faucets

[Mike Henderson]

That is why I installed the circulating pump have hot water in abou 3 seconds or less at the faucets

But what do you do when your water heater is a tankless, as mine is? My original water heater is tankless and the second one I installed is also tankless. Seems that if the flow was sufficient to get the tankless to light up, it would be heating all the time. And if the flow was not enough to trigger the tankless to light up, you'd just get cold water.

Mike

[Jerome Stanek]

But what do you do when your water heater is a tankless, as mine is? My original water heater is tankless and the second one I installed is also tankless. Seems that if the flow was sufficient to get the tankless to light up, it would be heating all the time. And if the flow was not enough to trigger the tankless to light up, you'd just get cold water.

Mike

You just add more tankless heaters before each faucet.

[Jim Becker]

You just add more tankless heaters before each faucet.
Actually, at our old property, we had two units; one for the "original" portion of the house (kitchen, powder room and original master bath) and one for the large addition. (new master suite, new guest suite, laundry) The distance "over the river and through the woods" for the cold water connection between the two pieces of the home was sufficiently far enough that it was very undesirable to try and use a single water heater for everything.

[Jack Frederick]

Mike, you understand the issue with tankless recirc perfectly. GPM x DeltaT X 500=BTU. Your tankless will have a minimum flow to initiate operation. I know Rinnai as I represented them for 30 yrs so will use their numbers. You can read the flow to .1 gpm on the touch pad. Generally min flow is .6 gpm to fire but it will hold operation down to .4 gpm. Minimum fire is 15 kbtu but again will hold fire down to about 10kbtu. So you must have a large enough Delta T and sufficient flow to initiate fire. To low a flow and to little DT and it will sit perfectly normally waiting for things to happen. Early after we introduced the tankless in ‘99 to the US market a customer wanted “instant” hot water so he put a honker circulator on it. I think it was a taco 0013 which is a hi-head pump and plugged it inot a socket. It killed the unit in 6 mos and Rinnai’s don’t give out in 6mos so we sent it back to the factory. Upon analysis it was found the unit had fired 88,000 times and had equivalent of 45 yrs of flow. Ridiculous. I have had success with the newer Rinnai’s with their wireless control with a wireless switch next to the kitchen sink up under the lower lip of the cabinet. Bathrooms have the wireless motion sensor so when you enter it makes the circ. The unit shuts down upon a warm return temp. That is on-demand recirc. In my last house I had this system and it had a the circ in the unit.

[Mike Henderson]

Bathrooms have the wireless motion sensor so when you enter it makes the circ. The unit shuts down upon a warm return temp. That is on-demand recirc. In my last house I had this system and it had a the circ in the unit.

That's an interesting idea about on demand recirculation. I'm going to look into that.

I really like my tankless water heaters. In southern California we can mount them on the side of the house, so I recovered the space where the tank water heater was - it's now a closet for things like vacuum cleaners, and accessable from inside the house.

Mike