Hi all:
Do folks here have any experience in switching to tankless natural gas water heaters? We’re just beginning to explore the possibilities and would love to know what experiences you’ve had.
And as tankless as water heaters might be, I am as thankful as can be for the CC community’s advice!
Happy Thanksgiving to all!
We looked into it but unless you have good water (not hard) tankless water heaters are more trouble than they are worth.
We have had Bosch Tankless water heaters for 10 years with hard water and no issues. Currently have Navien in our new home build and would never go back to a regular water heater. Depending upon the size of the house and location of the current water heater, you may need more than 1 due to the time required to get the hot water to the various bathroom locations. Very energy efficient.
We explored it years ago, when I thought there would be tax benefits. But it turned out that residential would not qualify. I didn’t like the high cost (though admittedly when we eventually did replace old WH with similar tank model it was pricey due to installation costs and building code changes… $600 unit was over $2k installed). Also one article I read said the tankless would require annual maintenance. Probably folks here could disprove that rumor.
Now a friend in NY did go with tankless WH a few years ago. In his 1960s split level house it has never worked well, despite many return visits from the installer and fix attempts from repairman. His old WH had been ok. He did WH replacement at the switch from oil to gas furnace. As you can imagine it is a huge frustration for him and wife to no longer have reliable hot water in the master shower. I assume it is an unusual situation, but it has made me leery.
We’ve had tankless at both our current and previous home and installed one in our cabin (well water) this past summer. Each place also had/has a water softener system. They’ve performed beautifully for us, no issues at all. The one at our main house also has a device that provides instant hot water to all faucets/showers in the house.
I’ve never heard that they need annual maintenance; we haven’t done that. I like the fact that they are compact, off the floor, and we never need to worry about flooding from a broken standard water heater.
I guess I can provide some feedback as a satisfied 20 year (ish) owner: We had one installed in our then new home, with a recirculation pump, solar assist, and a water softener. Because this was a new build, there is some “extra” plumbing under the sinks that supports the recirc bit of it. It has not been serviced, as we have been unable to find a company that does the service. After some experimenting with the recirc pump, we have been very happy with it. We have the recirc pump on a remote control (on our phones), so we turn on the pump when we need hot water. (Our builder had us on a schedule initially - e.g. on at 6am for shower, 7pm for evening dishes - but that really didn’t work for us, especially with two kids, and a telecommuting worker.). Our water heating bill is negligible - our gas bill only goes up when we use the heater in the winter. We’ve had to have some service on the solar assist, mainly related to dripping due to water pressure in the panel.
In short, we have been pleased with this choice.
[Funny aside: We have an image of the piping that connects all this together - with arrows and numbers and an associated description of how it all flows - think Alice’s Restaurant. It is no longer accurate as work was done to simplify, and improve the flow, but I still have the original, and always get a giggle when I run into it.]
My new house has one. The fact that it takes a little extra time to heat up takes some getting used to. And it does require annual maintenance. My plumber does it for a couple hundred.
We investigated a couple of years ago, and again within the last couple of months. While we like a lot of the efficiency aspects, they are still a no for us for two reasons. One, our water is extremely hard. Neighbors have had repeated issues because of that. Our second issue is location and venting. When we upgraded our gas furnace a few years ago, it went from venting through the roof to venting out through the foundation and we had to have 2 pvc pipes installed right out front. I absolutely hate it but because of the location of the garage, deck, CA unit and gas meter, we had no choice. Sales/installation folks say they could vent a tankless water heater right next to the furnace pipes but I hate the look of what we already have. We have had to redo our planting beds because the exhaust killed a few shrubs. The landscaper we hired most recently said we just can’t use plants to screen the vent pipes so now they are visible from the street.
We’re doing tankless water heaters in the new house. My main concern was that while they’re great for extended use such as multiple people showering one after another, they’re not so great for simultaneous use at more than two or three locations. That’s why we’ve had ours zoned to serve separate areas. We had two very large tank type water heaters in our former home and I’m confident that the operating cost of the tankless ones will be far cheaper.
Big fan. Love that you never have to worry about running out of hot water (though with teens that may be detrimental to your water bill). Had one installed with new furnace about 10-11 years ago. No complaints. Agree it has almost no impact on gas bills - our gas bills are minimal outside of heating season.
Thanks so much for all the thoughts on this.
I went to Home Depot this morning and saw how small the tankless heaters are in relation to the tank kinds. HD also claims that if you order by noon, you can get the tank or tankless heater installed that same day. That seems very optimistic to me, but it’s nice to know it’s an option.
Assuming we don’t go the HD route, do you call a plumber to give an estimate? Or do I need to call an electrician? Or have the gas company come out? Any thoughts on this will at least give me a start, and, worst case, I can reach out to HD.
We used HD in 2018 when our hot water heater started leaking…. very fast. HD, at least in our area, is geared up with contractors to do instant work. We called in the morning, and everything (including all the pricey rework for new building code) was completed that afternoon. They did haul-away on old unit. As far as I could tell doing research many years ago, no price difference for HD same-day vs planned …. and the units don’t seem to ever go on sale.
More info: Our old HD was 25 years old. We had been contemplating a proactive replacement before an upcoming 3 week vacation, so timing was good. We have an unfinished basement and drain, but really glad it happened when home. Water just kept coming to replenish the unit. When the new one gets older, we may decide to turn off the input valve before long vacations.
We had an awful experience with a Bosch tankless heater installed about 20 years ago and replaced with a tank after 10 years of problems.
At that time, the recirculation pump didn’t work with it so the typical wait time for the hot water in the master bathroom was about 4 minutes, no exaggeration. And our house wasn’t a McMansion. The heater was very sensitive to gas pressure and would shut off with a tiny drop, or whatever else triggered its discontent. I learned to do most of the resets and small repairs myself but still, we had to regularly call one of the few people who knew how to fix them - but it was considered a luxury item, and the service was priced accordingly.
When we finally gave up on it, our gas bill with a high-efficiency tank (but nothing super expensive) didn’t go up at all.
Funny thing is that all our European friends see them as an obvious choice and use them without any issues.
This is what scares me. We had a plumber to do some other work a couple of months. For kicks, I asked him about tankless gas water heaters. He thought that our utility closet was too far from the gas main/meter and that we would have problem similar to what you described. Then again, it was just a quick look while he was there working on something else.
I guess it can’t hurt to call in Lowe’s, HD, and some other installers and get several opinions. Our utility closet is quite tight with the tank water heaters plus the other stuff, and it would be great if we could go wall-mounted on a tankless. Our current tank WH is working fine, but is getting up there in age, so we’ll have to replace it. I would dearly love to reclaim some of the real estate in the house by going tankless.
I wouldn’t count on HD or Lowe’s for installation of these foreign toys, unless things have changed dramatically since I’ve last check.
Space saving is real but not that huge, there is a lot of heat coming out, and the flue needs to have room around it, be properly routed out, etc.
I “invested” in an electric tankless in a vacation rental home, thinking it would be great for groups taking showers, I had to pay for an upgraded electric panel to run it. I also paid for a water softener ($2600!) due to hard water. I thought it would be worth it.
I had nothing but issues from the start, replaced the circuit boards and individual heat things several times. We kept having to flip breakers to reset it. I actually ended up ripping out the tankless, putting in an oldschool one, and having to pay to build out a place to enclose it as the water heater closet opening was too small for the tank one and had the softener in it.
Calling in our home renovation expert @coralbrook - any thoughts on Tankless water heaters?
I’ve started to wonder if maybe they work better in new homes designed with them in mind, rather than renovations.
If you are replacing a natural gas tank, you would want a mechanic familiar with the tankless brand to install it. The mechanic can do both electrical and plumbing work, including natural gas lines.
Our house has a hydroair system where a single boiler works as the heat source for forced air house heater and hot water. We did not choose this option; our previous owner did. The owner never serviced the boiler, and it went kaput shortly after we moved in. We did a complete replacement, and the mechanic recommended installing a hot water holding tank to serve as a buffer for those occasions when one owner is taking a long shower, and the other is running the dishwasher and clothes washer at the same time while taking a giant bath. 
Unlike gas tank water heaters, storage tanks are just big stainless steel water bottles. We service the new boiler regularly.
My husband wants to put in a hot water storage tank. Our hot water comes off our boiler and we seem to have a continuous supply. I do not want a storage tank…and I’m lobbying for not having that when we replace our heating system this year.