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Adding a Water Heater - crokett™ - 02-25-2025
I wanted this to be a different thread discussion. Probably not a project I will get to for at least the next 2 months, but I am thinking about it now. I can always come back and find this thread later. My house is a modular, 2 15 x 70 foot boxes. It has a finished upstairs, the upstairs bath is right about the middle of that 70'. The factory was supposed to run a chase and the 3" drain stack up the wall by the stairs to that bathroom. They didn't. They ran it up the wall of the downstairs bathrooms at one end of the house. The problem is the water heater is at the other end of the house. The builder instead of figuring out a way to route the water pipes up the middle of the house took them all the way down to the chase, up and then back through the attic. I'm guessing 80' or so of pipe by the time it's all said and done. They had to open one of the walls in the middle of the house to get the drain down to the septic anyway so I have no idea why they didn't just pull the water lines. I'd like to have hotter water upstairs and I'd like it to get there quicker. I am thinking of a second water heater, 30 or 40 gallon in the crawl space at that end of the house. It would be electric. I have space in the panel to feed it. The question is whether to tie that heater into the entire house so that both water heaters are feeding everything, or isolate the upstairs bath and maybe the downstairs bath on that second heater. That would then put the master bath, kitchen, washer and dishwasher on the main one.
I haven't been under the house to see how things are plumbed. A while ago I looked into a recirculating pump but that only solves one problem. The water is still losing heat. A second water heater would help solve both problems and give me additional capacity, especially if it was just tied into the entire house. Is there a problem with doing that if the water isn't being drawn from them equally? Like the kitchen would mostly be pulling off the main water heater.
RE: Adding a Water Heater - EatenByLimestone - 02-26-2025
If your water isn’t really hard, I think I’d look at adding a small tankless inline to that bathroom. I’d rather pull wire than add a full tank. I only mention the water hardness as I’ve read that the tankless stuff needs to be flushed somewhat regularly for best results/life. If the water going to the tankless was pre warmed, it wouldn’t draw much energy. You’re only raising the temp a little bit.
RE: Adding a Water Heater - fixtureman - 02-26-2025
I added one of these to ny house. It does work pretty good
https://www.lowes.com/pd/Watts-HWRS-Steel-Recirculating-Pump-Universal-Water-Heater/5015235213?gStoreCode=633&gQT=1
RE: Adding a Water Heater - blackhat - 02-26-2025
First blush, add a second heater close to the first. Pipe them in parallel and use a valve to balance the flow between them. Best if they are the same size and same thermostat settings. Add a recirc to solve the time lag.
RE: Adding a Water Heater - sleepy hollow - 02-26-2025
I have two electric 40 gal WHs side-by-side in my basement about 40 ft from my master bath. They are plumbed in series for normal operation and in parallel for isolation of either one in case of a problem.
I am remodeling my master bath as I write this. The pipe run makes for about 45 sec to a minute delay to the MB fixtures. I looked at a range of options to fix this annoying situation. I looked a recirc pump, but it was too complicated and certainly is not efficient as far as energy cost goes.
I looked at adding another tank in my attic space behind one wall of the MB. But I rejected that because it would require a lot of work to reinforce the attic deck and also adds another unit I don't need, except for a few seconds whenever the hot water line is cold.
I also looked at installing a small tank point-of-use WH in one of the vanity bases, but again this was too complicated. Ultimately I gave up and decided it was not worth spending anything on. I'll live with the annoyance. It's really not that bad.
In your case, however, I can see the issue as being worth addressing. I would look at possibly adding a POU tank if you could make it work in the bathroom space. I would not favor a recirc pump solution. I would also avoid a larger tank just because when it goes bad it will be a pain to change out since you cannot locate it next to the existing one.
Certainly I may not fully appreciate your layout and situation, but a small tank to use as a buffer until the hot water arrives from the main tank could be a solution. That was what I ultimately came to see my problem to be - how to heat that cold water in the line between the BR and the main tank. A POU tank with the proper flow could be an answer. They make 110v units that can work if I recall correctly. Usually they come with 1-5 gal tanks, I think. So you have hot water immediately until the main hot water arrives. Problem solved, or greatly ameliorated, it would seem.
RE: Adding a Water Heater - crokett™ - 02-26-2025
(02-26-2025, 10:14 AM)blackhat Wrote: First blush, add a second heater close to the first. Pipe them in parallel and use a valve to balance the flow between them. Best if they are the same size and same thermostat settings. Add a recirc to solve the time lag.
possibly doable. the current WH is behind one of the master closets. there's no room for a 2nd heater next to it. I don't think I have the vertical space to add even a short boy in the crawlspace below it, at least at that end of the house. there's only about 24", 30 tops of vertical clearance. where I was proposing to add one is at the other end which a) has more headroom, almost 4' b) is easier to get to (a lot closer to the access door and c) is much closer to where the hot water is needed.
hence why I was asking about trying to plumb them both into the entire house or just cutting that bathroom off from the hot water to the rest of the house.
RE: Adding a Water Heater - crokett™ - 02-26-2025
(02-26-2025, 10:53 AM)sleepy hollow Wrote: In your case, however, I can see the issue as being worth addressing. I would look at possibly adding a POU tank if you could make it work in the bathroom space. I would not favor a recirc pump solution. I would also avoid a larger tank just because when it goes bad it will be a pain to change out since you cannot locate it next to the existing one.
I was looking at a POU one a while back. the difficulty is getting electric up there to power it. a tank in the crawlspace the wiring is much easier to pull. the water pipes are already there.
How does putting a larger tank far away from the existing one make it any more difficult to change out than if it were located near it? if anything it would be easier to do given the locations involved.
RE: Adding a Water Heater - sleepy hollow - 02-26-2025
(02-26-2025, 01:45 PM)crokett™ Wrote: How does putting a larger tank far away from the existing one make it any more difficult to change out than if it were located near it? if anything it would be easier to do given the locations involved.
It probably does not make a difference. I had in mind the plumbing I did to make the heaters either series or parallel, and thought that might be more of a pain to do in two locations vs 1, but frankly, you know your space(s) better of course. I honestly do not have a good grasp on your house and how easy/hard it is to rough in whatever you need for the second location vs. a POU. I am thinking traditional stud walls with drywall. So, I am sure I'm missing something there. As you can gather from my situation, adding a second WH is a good idea in principle as far as I am concerned.
RE: Adding a Water Heater - crokett™ - 02-26-2025
(02-26-2025, 02:48 PM)sleepy hollow Wrote: It probably does not make a difference. I had in mind the plumbing I did to make the heaters either series or parallel, and thought that might be more of a pain to do in two locations vs 1, but frankly, you know your space(s) better of course. I honestly do not have a good grasp on your house and how easy/hard it is to rough in whatever you need for the second location vs. a POU. I am thinking traditional stud walls with drywall. So, I am sure I'm missing something there. As you can gather from my situation, adding a second WH is a good idea in principle as far as I am concerned.
Yeah. it's all clear in my head. As to locations. viewed from the top, the house is a 70x30 rectangle. the current WH is behind one one of the master closets at one end of the house, maybe 10' from that end. the electrical panel is at this same end of the house. There's a bathroom upstairs located almost exactly in the middle of the house. the hot water has to go through the crawlspace approx 50', up through a chase and then back about 20' give or take to reach the bathroom. If I were to pull power for on demand, it would have to come through the crawlspace, up through the chase (maybe I haven't checked to see if there is room) and back over to the bathroom. I can't remember if it is a 2" or 3" PVC pipe that was installed as a chase.
a second water heater the electrical doesn't have to get pulled as far and the plumbing is already there. it decreases the time to get hot water to the upstairs and adds capacity. adding it near the existing doesn't decrease the time and I am not sure there is vertical space in the crawlspace to do it anyway. The crawlspace is about 18" high at the end with the current heater, and close to 4' at the end where I would put one.
RE: Adding a Water Heater - blackhat - 02-26-2025
Given the restrictions you’ve described, a second heater, maybe a size smaller at the far end makes most sense. Set it up as a stand-alone.