I have had one and loved it. Super hot immediately. Never ran out of hot water. It was a small house and I live in the South, so it worked perfectly, and we only needed one. If you live where it gets cold it might not work as well as you want. If your house is bigger you made need more than one. If you get a gas run water heater, it has to be vented to outside. That's the long and short of it. Questions?

We have 2...one does just the master bath and one does the rest of the house...10 yrs in and no problems. Very efficient.

Have had one for the past 12 years. Hangs on the exterior of the house.

It does get cold here, live in a 1400 sq ft house. 2 baths. You can't do laundry and have someone take a shower at the same time. Two people can't shower at the same time either. Would this solve the problem?

It should...what will happen is the hot water won't stop, but the flow of water will diminish some as other things demanding hot water come on. The only other thing we've noticed is that it doesn't want to trickle hot water...it gets confused and doesn't make hot water, so if you use it, you need to use it....keeping a dribble of hot water to rinse dishes, for instance, doesn't work.

But I was *very* particular when we built our home so, despite the cost, I wanted an uninterruptable supply of hot water for my shower, thus the dedicated unit to the master bath. Also, it is on the other end of a fairly long house, so one unit would mean it would take forever for the hot water to reach the master bath. The beauty is though, the unit is on *only* when hot water is demanded. So the one that feeds the master bath probably runs no more than 20 min a day....vs. a tank that would have to keep lots of water hot 24/7.

My nephew has one on his new home in Louisiana. We were asking him about it when we were there for Christmas. They love. They have a good size house, there's 3 in the family but she babysits every day for family members. They just have one unit that is on the outside of the house under the carport area. It's a gas unit. He said he has not had any problems with it and would definitely do it again. We have been considering changing our regular gas water heater to one of these. I think they have been around now long enough to have the bugs fixed in them.

If you have natural gas, it can be a good option. If you have an electric water heater, the new one would probably need to have the electric line to the heater to be upsized which can cost a lot.

In the right area, in the right family situation, they can be viable. Things to consider:

-MUCH more expensive than conventional tank models to purchase and install

-retrofit where a tank model was located can involve expensive added plumbing costs - usually both larger size gas supply pipe (from the meter) and a maze of water pipes

-usually not less expensive to operate

-a bad choice where the water is hard because the passages can get blocked. Annual descaling in such cases can run several hundred dollars a year if done by a plumber, necessary unless the install was plumbed to facilitate a DIY job by the homeowner.

Can't be mounted outside in areas where freezing temperatures are normal. Shouldn't be an issue for kathsgarden replacing an existing tank.

"live in a 1400 sq ft house. 2 baths. You can't do laundry and have someone take a shower at the same time. "

This shouldn't be a problem. I'm shocked the tank has lasted this long, normal life is 10-15 years. Maybe capacity is limited because it's full of sand and debris?

A 40 gallon tank, better yet a 50 gallon one, should easily allow several 10 minute showers AND laundry AND even a dishwasher at the same time. In contrast, tankless models have a flow rate limitations. Getting more than 3 gallons per minute of flow isn't a gimme. That precludes a shower plus running the dishwasher or a hot cycle of laundry at the same time.

We do and we love it. It's mounted in our laundry room. Unlike a water tank that needs a lot of space, the tankless model is attached to the wall where it takes up very little space. As mentioned above, we do not store hot water 24/7. Instead we only use hot water when we need it. Our water heater is powered by propane as we do not have access to natural gas where we live.

One of the things I like about it is that we never have to worry about running out of hot water. We could have 30 people each take 30 minute showers and all of them would have all the hot water they wanted, unless we ran out of propane first!

This is our second on demand water heater. The first was installed in 1993 or 94. Over the years, they have improved a lot and hubby upgraded to a new one a few years ago. We do have hard water here and the first one used to need occasional cleaning which hubby was able to do himself. We have since installed a whole house water filter and that has eliminated the problem of minerals getting in to the water heater.

Because our kitchen is on the opposite side of the house from the on demand water heater, we have installed a five gallon electric water heater under our kitchen sink to run the dishwasher and for hot water from the kitchen sink. Our reason for doing this was because it's such a long run from laundry room to kitchen, we would have been waiting for cold water to clear the line before the hot water arrived every time we used the water in the kitchen.

We are very happy with our system and I highly doubt that we will ever go back to a water tank type heater. When the day comes that we move from here, our new house will be upgraded to a tankless system if it doesn't already have one.

I don't understand why replacing a tank with tankless would require a "maze of water pipes" as the supply lines are already there.

We have LPG and it works fine. At the time we were not impressed with either the cost or the efficiency of the electric versions.

"If you have an electric water heater, the new one would probably need to have the electric line to the heater to be upsized which can cost a lot. "

I've wondered about the differences and cost. more $s for the electrical line would be enough to keep me from it. but then, it's just me and I can schedule use of water. I seldom use hot in the washer except in the summer when I have no choice. and my water is heated by the sun 6 months of the yr, so no need for the water heater then. my water heater is very old - probably the original, so from '96.

Our tankless is very near the laundry room, second bath, and kitchen. No issues with immediate hot water. The main bath is on the other side of our 1700 sf house and it does take a little while to get hot water there in the colder months. That's a minor inconvenience. Would never go back to a tank.

I have a small one (electric) for the kitchen only. I wanted to be able to have hot water and run the DW, even when the kids were all taking showers. It needed a dedicated 220v line and 50amp breaker IIRC, but fortunately it was installed near the electrical panel and the kitchen sink, in a new addition.

As Annie mentioned, it has a sensor which turns off the heat if the water flow is on a trickle--to guard against burns. My father has one for his whole house, and if the water flow is turned too low, his has a shut-off on the heater--which means if I forget and turn the kitchen faucet to a trickle, I have go to the laundry room to re-set the button.

My father has one for his whole house, and if the water flow is turned too low, his has a shut-off on the heater--which means if I forget and turn the kitchen faucet to a trickle, I have go to the laundry room to re-set the button.

Ok, that would be annoying. I'm glad ours isn't set up like that.

We don't have a reset button...instead, just the hot water stops coming. As soon as I increase the volume demanded, it goes back to supplying the hot water.

Also wanted to mention, though I'm sure it'd be an issue with many water heaters, not just tankless, we have the heat vents coming out of the building in a corner by the garage which seems to accumulate blowing snow in the winter. If the vent is blocked, the heater will not come on. We learned it the hard way by having to shovel out the vents after a blizzard. We now since protect those vents from snow in the winter and make sure they have plenty of air circulation for them.

We have one, and it seems to work fine. The highest temp it can give is 130. so if we want hotter, it's not available.

Here in California people need to have an emergency water supply in case water lines are broken in an earthquake, so many consider their tank water heaters that supply. That is lost with a tankless. We have water stored in the garage, and it is a nuisance, takes up space, has to be changed out periodically, plus use of plastic.

Hard to say if it has saved us any natural gas on the utility bill.

We recently switched from a tank. We had a specialized water heater that supplied our hydronic heat in the downstairs (in floor radiant) plus the household water. It failed in dramatic fashion just before Thanksgiving. The pressure valve failed and I woke up to the sound of running water. Messy with some overflow but not too bad. So we had to replace but also upgrade as our old heater was no longer code for potable water. Expensive no matter how you do it so instead of replacing with the same water heater with an interior coil heat exchanger for the hydronic heat we opted to switch to a combination boiler unite that does the same thing. It is supposed to save money. I hope so. Even more expensive. it has been a learning curve. Waiting for hot water is annoying. I have learned that turning the water on hard does not get you hot water sooner. It creates at the same rate. Still we do not have to maintain an enormous tank of hot water to fuel the floor-there are only about ten gallons in the tubes and it gets heated separately when just the floor is on. I am not sure exactly what is going on there. Because we would have to have the boiler for the floor regardless and I know that just household water is only a small part of our expenses (propane use drops through the floor in the summer) It seems to be the modern answer. At least it cant blow a gasket in the same way the water heater did. It has electronics that turn off the water and a maze of pipes.

I agree that it is in the kitchen that it is challenging. You have no idea how often you turn the water off and on and I have a lifetime of turning the water off. I could up the length of time that the unite maintains hot water but the savings go out the window. Sigh. Learning curve.

We replaced two hot water heaters with two tankless units (Rheem) about 10 years ago. They’re both natural-gas fired, installed on opposite sides of the house on the exterior. People can be taking showers in more than bathroom and no one gets frozen out. Having a never-ending supply of hot water is wonderful.

I have a noritz tankless excellent make sure you get a reliable heating company familiar with tankless units. Houzz does not stand by there products!!!!! They did not for me with an $ 800 vanity that was defected shame on them.

Thank you all for responding. I'm a little confused by the electric causing the installation to be more. Are you talking the cost of an upgraded electrical box? I need one anyway. I also need to have the electric checked out in the master bath. It flickers on and off all the time. I keep meaning to get it checked out but then something else keeps me busy and I forget. I could do those things this year. I don't want gas installed in the house.

I missed if there was an earlier comment this was an all-electric home. If so, I'd probably go with a hybrid heat pump/electric tank model for cost savings and ease of installation if an electric water heater is already there. AND if there's a suitable place to put it. They do make a bit of noise compared to the old fashioned electric tank types that are silent but they're much less expensive to operate. I'd avoid the expense of an on demand electric heater.

I understand that propane is an option where natural gas isn't available but faced with such a home's location, I myself probably wouldn't use propane. It's not as safe as natural gas. And, to be honest, unless the home had enough land for and I could afford something like a ground source heat pump installation, I probably wouldn't want to live in an all electric home.

Elmer, it is all electric.

it was installed near the electrical panel and the kitchen sink, in a new addition.

mamag - did you add on in the past 8 yrs or so? in other words, you added on and I didn't know about it? I miss seeing / hearing what you're up to in your house. did you post about it on one of the forums here? if so plz post a link to it. I haven't been on the bldg./remodel etc forums for a long time. only recently checked out some pages on kitchens.

Elmer, why would LPG be less safe than natural gas?

It is in the laundry closet with my washer and dryer

A Heat Pump water heater may be a good choice for some homes, but not if you're installing in a small closet. A heat pump water heater needs a 12 X 12 open space to operate efficiently. You'll also need a condensate drain or a pump to move the condensate to a drain. Before deciding on a heat pump water heater, be sure to review the checklist below.

Considerations

Do your research on the various models. My sister bought one when they were fairly new (Bosch, I believe,) and had nothing but trouble with it. I dreaded taking a shower at her house because the water would suddenly go cold or hot--I had to stay on my toes to duck out of the way in her tiny shower stall!

"Elmer, why would LPG be less safe than natural gas?"

Natural gas is lighter than air and so any leak will disburse into the air upward, outward and away.

Propane in gas form is heavier than air. It's dangerous for houses with basements or lower levels and especially so when propane appliances (water heater, boiler, furnace) are located in the basement/lower level. Any leak, however small, will allow gas to accumulate in the space from the floor up and not disburse away. Unfortunately, a frequent result is an explosion.

Someone I know had a Tahoe ski cabin with propane heating and cooking. The furnace and water heater were located in a garage, the house was above. Late one Friday night, he arrived at his cabin. Opening the garage door, he reached for a light switch. The spark in the switch was enough to ignite the propane and he was blown out to the street, narrowly missing his car. The house went up in flames and was completely destroyed. The guy was lucky, that might have been his last Friday night on Earth. He rebuilt the cabin eventually, all electric of course and with a couple of wood burning stoves for heat.

Interesting, though I'm not sure it's less safe...gas build up in a basement isn't a good thing regardless of if it accumulates near the ceiling or the floor.

You can be sure it's less safe.

The floors and exterior walls of basements are often impermeable concrete or masonry and any leaked propane remains and accumulates. Upper parts of a basement are typically wood structures and generally are not airtight so that any lighter than air gas can escape. There are often "crawlspace" sections and even vents. At worst, natural gas can escape up through the stairway and dissipate into the rest of the structure (or to the outside if that's where the stairway goes) so that no explosion danger is present. All the same, natural gas doesn't remain as a pool of flammable gas in the basement as propane does.

As an aside, explosions are a risk on recreational boats and are not uncommon. The volatile vapor of gasoline is also heavier than air like propane. There's a risk of explosion because of the possibility of gas vapor collecting in the bottom of the hull. Larger boats with inboard gasoline engines have "sparkless" exhaust fans in the bilges that are turned on and run for several minutes before starting an engine, to remove gasoline vapors that can cause an explosion when the engine is started. For the same reason, in recreational size power and sail boats, compressed natural gas or (historically) alcohol are preferred for cooking appliances. I had a 35 foot sailboat some years ago and it had an alcohol range and oven, they're now less common. Boats that use propane have venting systems for the risk of vapor in the hull.

It's also a reason that even smallish sailboats often have diesel engines, because diesel fuel vapor doesn't present an explosion risk as gasoline vapor does.

OT--Hi, desertsteph! No, it was added in the addition we started in 2008, in the party room (behind the kitchen sink, so it serves both rooms). I mentioned that it was in a 'new' addition to clarify that the electrical and plumbing were easy--since we didn't need to tear apart walls to run lines.

Thank you so much for your kind words. I have been busy the last couple of years, and haven't had as much time to spend on GW/Houzz, or to work on home projects. It's good to hear from you again. :)

Interesting Elmer...might be worthwhile for us to get propane detectors in our basement where the heaters are.

Detectors would be useful but perhaps not enough. If it were me, I would also consider installing some kind of ducted ventillation system (with a fan and switch not located in the basement) with an air intake at basement floor level, set on a timer to operate an hour or two through the day.

Propane has always made me nervous because of too many accidents I've heard of, even in my area where propane isn't real common until you leave inhabited areas. I wouldn't be comfortable having it in my house. Maybe when it's time to replace the furnaces you might want to consider getting air source heat pumps. Those together with solar panels would provide cheaper and safer heat than propane furnaces.

Elmer, don't make assumptions about me and my house. We have no furnace...we have geothermal heating and cooling and 5kw solar panels on our roof. We also have closed cell insulation, solar tempered house design and other energy saving designs in our house. But we have no nat gas in our area and have lived with LPG all our lives without incident. It runs our gas fireplace and our hot water heaters.

I guess I'm guilty of coming to what was the most likely assumption following your incomplete information.

In your shoes, which I'm not, I'd still eliminate propane when reasonably possible. Does your hot water system take advantage of the ground source heat pump equipment? It can, and that's especially easy in warmer months when the system's job is cooling rather than heating.

I'm glad you've lived with propane for a long time without incidents and I hope that continues. I've been a car driver for over 50 years without an incident. I still put on my seat belt before starting the car.

Good grief.