Put a heat pump hwh in your garage?

We have a propane tankless and so far we have been happy with it. We switched it out 5 years ago when our tank one kept running out of hot water and DH was always the last to shower with the cold water. Ours is outside and freed up the space the old water heater took in the garage for a fridge. Ours has been trouble free and it is so nice to never run out of hot water. The one thing that is a bit of a pain though is if power goes out we don't have hot water as it uses a small amount of electricity to ignite it.

As for size we said we wanted one that could handle 2 showers and a dishwasher at the same time and the plumbing company sized it for us. So think about what you want to have running concurrently. Ours has performed well for our purposes based on that info.

I regret. Tankless is expensive to buy, expensive to repair, labor intensive to maintain, and has demonstrated absolutely no cost savings over the multi-decade proven tank.

Mine has been trouble free for 6 years. But it's gas.

You have to want endless hot water though. Otherwise yes maybe other options would be better for you.

@strategery I am curious how tankless are labor intensive to maintain?

It’s a $150 yearly maintenance. That’s it.

I‘ve had a gas tankless for 26 years. Zero issues. Virtually no maintenance. A gallon of vinegar is all you need to periodically flush it. We’ve done it maybe 5 times over the years and replaced a pressure sensing diaphragm maybe twice. All simple to DIY, and inexpensive. We have excellent water here though. No real minerals at all.

But electrical tankless gives virtually zero advantage over tanked electrical. Especially considering the electrical upgrades required.

As has been said but just wanted to clarify.

Gas vs electric is a huge difference.

Maintenance can be DIY or $150 a year. Both are more than a tank. Tanks do a bit better with neglect and surely this is water/region dependent.

Electric should be heat pump in 2021. They have gotten so much better. But doesn't help OP's space issue.

I wanted to know what stratagery meant by labor intensive because the only thing we have had to do to maintain ours is the descaling with vinegar. It really was no big deal. We did it ourselves.

We did have an issue with our propane tankless. Showers were going cold and it was throwing error codes. The unit was 3 1/2 years old. The first plumber we hired did nothing. Looked through the little window at the burner and said it’s fine. Must have been a blip in the gas. Of course that was false. My DH called Rinnai to discuss what the issue could be. Plumber came back out and we got him on the phone with Rinnai. Plumber went through a few things with them to determine what was wrong. Plumber got off the phone with Rinnai, said he didnt have the equipment to fix, left and we never heard from him again. Rinnai gave us names of 2 places they had on their list of servicers and ended up getting it fixed by a gas company. It was the flame rods. The guy cleaned the flame rods and it worked fine after that but since it was still under warranty he had them replaced.

I find on demnad hot water works best when ibstalled close to where the hot water is needed in this case not really. I think if the OP is wanting this system they will need more than one.

Great info from all, thank you! I'm glad I asked. Doesn't seem like something we should do. We figured since we need to put flooring down in the laundry room we might as well look into all options of what to do in there before flooring. We have zero problems with our tank though. Leave it alone and give up the idea of having a pretty and functional laundry room? Worth it to move to garage? (we have a 3-car garage with tons of space right outside the laundry room wall)

We have a Navien NPE-240A unit. There are 4 pages of maintenance instructions in the manual. You need a separate pump to flush vinegar through the heat exchanger, at least yearly. There are a bunch of valves to open/close and hoses to connect to perform the cleaning procedure. There are also 3 filters to maintain. I can imagine this being too complex for the elderly.

If you hire somebody to do it then that is an extra expense. That would offset any "efficiency" savings.

We had an electric tankless in our old condo which was 1920 square feet. Never had an issue.

We installed a gas tankless in 2013. No problems at all. The size & number needed was decided by the company installing our Rinnae brand, which was purchased through Ferguson. Our choice was determined by space considerations.
As mentioned, it is helpful to place it close to your kitchen/bathrooms. Our location was not ideal. The size of the gas line had to be increased, adding to the cost. We have no regrets, but moving yours to the garage sounds like a much cheaper option. As previously mentioned, it does not work in a power disruption. It also did not improve the look of the laundry room. There are pipes running above & below. I wish I had known what the finished installation would look like, as I would have changed the placement.

We have a gas tankless and love it. Our one problem was our eldest started taking really long showers.

Thats not why he's taking really long showers...

We have had two propane tankless water heaters, one on each side of the house exterior, for the last 15 years. They work flawlessly and have required minimal (diy) maintenance.

We installed a gas tankless water heater 20 years ago before they became popular. We stuck with tank heaters in subsequent homes. It doesn't really save money on gas. The initial start up takes a lot of BTU's to get the water heated. Plus output is limited. In our family of four, there was always a shower or laundry running. Sometimes there just wasn't enough and you would get lukewarm water. For a single person or couple, it could be efficient. For a large family, I would say it might be inefficient.

You can get a larger sized tankless. We can have 2 showers running and the dishwasher with no problems.

Then you have to look at how many BTU'S you are using. Is it actually more efficient? How often is the hot water being turned on? Everytime you turn it on, you have high BTU output, initially. We always had someone home. Now, that we are empty nesters and no one is home all day, I would be more likely to consider it.