Tankless Hot Water Heater Reviews

In this tankless hot water heater comparison we review four brands that specialize in tankless water heating using different fuels and with heaters ranging from a couple hundred to thousands of dollars.

Stiebel-Eltron Electric
The Editor Pick Editor's Pick

Stiebel-Eltron Electric

Stiebel-Eltron Tempra 20 Features:

Fuel Type: Electric
Warranty: Three years
Voltage: 240V
Amps: 80A
Watts: 19.2k W
Recommended Use: Small Home
Dimensions: 14.2 x 21.75 x 4.6 inches
Weight: 21 lbs
Temperature Range: 86 - 125 degrees
- Automatic anti-scald controls
- Front-panel digital temperature control
- Thermal cut-off safety sensors

Avg. Price: $499

Learn More: Buy Now or Learn More Here

Paloma Propane or Gas

Paloma Propane or Gas

Fuel Type: Propane & Natural Gas Models
Warranty: Ten years Main - Three Year Parts
Recommended Use: Medium to Large Houses
Dimensions: 25.4 x 14.8 x 11.125 inches
Weight: 55 lbs
- Oxygen-depletion sensors
- Excessive heat sensors
- No standing pilot light

Avg. Price: $1,249

Learn More: Buy Now or Learn More Here

Aquastar 2400E

Aquastar 2400E

Bosch Aquastar 2400 E Features:

Fuel Type: Propane or Natural Gas
Warranty: Twelve Years Main - Two Year Parts
Efficiency Rating: 87%
Recommended Use: Large Homes
- Made for Two or more bathroom houses
- Save up to 50% on water heating bill
- Outdoor units available

Avg. Price: $999

Learn More: See more Aquastar On-Deman Water Heaters!

Takagi T-K2

Takagi T-K2

Takagi TK2 Features:

Fuel Type: Natural Gas & Propane Models
Warranty: Seven years Main - Two Year Parts
Recommended Use: Medium Sized Home
- One of the best energy factors for tankless heaters
- Automatic freeze protection
- Optional Backflow Prevention kit

Avg. Price: $1,499

Learn More: Get the TK2 and TK3 For Less Here!

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What research says

What is a tankless hot water heater?
Normal household water heaters hold the water in a tank and continuously heat it, even when you\'re not using any water. The temperature must stay warm while you\'re sleeping, while you\'re at work, and even while you\'re on vacation if you don\'t turn down the thermostat before leaving. A tankless hot water heater is \"on demand heating\", meaning that the water is only heated as you need it in real-time - thus saving you anywhere from 10% to 50% on your water heating costs.

The Stiebel-Eltron Tempra 20 is the only tankless water heater in the comparison to run off of electricity. This has the added benefit of making it easier to install, and somewhat safer, but may require you to upgrade your circuit-breaker box to handle the enormous load needed to heat the water. This Stiebel Eltron model is not made for large households, but is a very affordable and efficient option for small bungalows where only one shower will be running at a time. It won the editor\'s pick primarily for its affordability and ease of installation, although some of the models below may be a better option if you\'re looking for a more robust water heating solution. The biggest problem we had with this unit\'s review is the lack of a comprehensive warranty beyond three years.

The Aquastar 2400E tankless hot water heater is made by Bosch, known for their quality engineering. There are smaller Aquastar options available (see the link below the product) but we chose to review one of the large tankless hot water heaters by Bosh - the 2400 E. This unit is probably the best option for large families where there will be more than one hot-water need running at the same time - such as two showers, or a shower and a dishwater, clothes washing machine, etcetera. The ability to use propane as a power source is great for off-grid applications, such as mountain homes. We also like the long, twelve-year warranty on the heat exchanger, but felt they could have added another year to the parts in order to bring it up to par with the paloma.

The Paloma tankless water heating system is another great choice for large homes using more than one water source at the same time. It also has the added benefit of using either propane or natural gas, depending on which model you choose. However, it is a rather large unit that doesn\'t come with a lot of bells and whistles as far as controls are concerned. Overall it is a good system, but we felt other options were slightly better. The Paloma\'s warranty is one of the best in the business at ten years on the heat exchanger and three years on all other parts.

The Takagi T-K2 water heater is the most expensive unit reviewed, and if have the budget it is worth the money. This hot water heater is full of features, such as the remote control, and great safety options, as well as high-end materials like non-corrosive copper and brass. There are two downsides to this unit - The price, and the mediocre warranty. Don\'t get us wrong, seven years on the heat exchanger and two years on everything else is a decent warranty, but it doesn\'t stack up against some of the other options above in that department.

Note: Looking for a cheaper option? Try these tankless heaters.

Colorado Home Owner said:

Does anyone know good plumbers in Denver, Colorado who can install tankless hot water heaters? I tried a few from the phone book and nobody knows how to do it. :-(

Keith said:

I do only tankless water heater installations. Rinnai Certified and Listed as preferred installer in Colorado.
Will be getting my website up shortly in 2008.

Keith Bohall said:

There are other costs associated with tankless, I only install water heaters, and have seen the downfalls of not having an expert involved in installation, gas flow, water pressure, proper venting make important issues in tankless if not right away, then down the road. Tankless should give you many years of trouble free operation and performance.

Jeremy said:

I have been using tankless heaters for almost a decade. I recommend the Hubbell models (formerly SETS). The Hubbell design is much improved from the former SETS design, and the heaters are built like tanks for a reasonable cost. Electric only, as far as I know - I don't have gas in my area so that was my only option.

Matt the Tankless Guy said:

I have installed over three hundred tankless units for residential domestic hot water application in every brand there is. Noritz is the best brand of tankless or as the noritz people will call it briefcase water heater. they have units that will fit every application, and i even helped on the install at the Wynn resort in Las Vegas where they have no boilers no storage tanks just one wall with 24 noritz units on it and they can keep up with more than the demand…… were talking 500 rooms or more that never run out of hot water and is about 300% more efficient than the old boiler and storage tank routine. not to mention when the tank goes out you have to replace the whole water heater. with a tankless or briefcase whichever you call it the entire unit as a whole will never need to be replaced……. of course it is a machine and like all machines parts wear out but with noritz and goHot which another brand of briefcase every part is interchangable and can be taken out with a phillips head screw driver, so if you were so mechanically inclined yourself you can work on them with out a lot of technical mumbo jumbo. And if your worried about temperature rise in states like colorado which is where im from and where i’ve installed a majority of the units i’ve worked with that’s good your worried about that. Rinnai, Noritz, goHot, and Paloma would be the prime choices for areas with water coming in at 50 and below. Of course as long as you size it right any heater will work you just might be spending more in maintenance and installation for proper application and maximum efficiency. and for the super green home owner that is looking for the most efficient model Noritz and goHot are the only heaters right now that offer 93.3% efficiency. Any other questions feel free to email me matthewmccart@msn.com

Fredrick James Shearin said:

I would like a un-baised opinion on the Titan Tankless water heaters

Adelina Leon said:

I currently have a water tank to heat up the water in my house, it uses gas. would it be worth (money wise monthly) for me to change to a takless electrical WH?

Barbara said:

We had the Rinnai R85 installed in a home we were having built in 2006. We stated to have problems in mid 2008, when the unit started to flash a code 12. This has been ongoing since then, and now, we have been out of hot water for a complete week. The plumber has dismantled ever part trying to solve the problem. Rinnai to date, refuses to replace the heater, and wants us to continue to pump more money into it (we’re up to ,500 now). After a review of the BBB yesterday, I see that the BBB has given them an F in their consumer ratings, and has revoked their accreditation as of March 25, 2009.
I think it’s time to buy another brand and give up the ship.

Ed Haney said:

I own a Takagi TK jr.
When we first purchased this unit it worked pretty good. We have a 2 bathroom home about 1580 square feet, 2 levels. We started having trouble whn we bought new washer and dryer appliances. With the new efficient washers these days that use very little water the bursts of water turning the demand water heater on and off started to screw it up. So we figure at least. Now we are consatntly battling it unit for always shutting off. To have a shower has turned into a fight.. We talked to Takagi sales reps. And they could help much and there are not a lot of plumbers that know much about these units. So we think maybe a short exhaust pipe might help and we check the water filter often but have never had to clean it.. So we are looking to change this unit out with a diffrent vrand, like Bosch or another takagi.. We may have to relocate the unit on the wall to another wall for shorter piping for the venting. Plus the TK Jr. maybe too small for the usage we demand. I was told that it was good for a average home of 4 and about 1500 sq.ft. Does anyone else have this unit and have issues??

Fred Barnes said:

Bought a Bosch Aqua Star SX250 a couple of years ago and installed it myself. Ran fine with no problems until a violent storm got water down the exhaust vent. Ran into first problem with Bosch units. No one wanted to service the unit. The reason...parts availability. The only place to get parts is in Vermont.
If you are thinking about doing it yourself call around and see if anyone locally will service it when it breaks down. Make sure you employ a drain in the venting system to keep rain water out.

Karla said:

My takagi jr is junk!! I didn't like tech support telling me my plumber wasn't qualified to install it. I really didn't like tech support telling me I broke by not taking care of it. Are you kidding me???!! Hot water; That's all I ask. Takagi is the worst----don't agree with me; wait a couple more years; say 4-5 and we'll see how you like yours. Good Luck

Mark said:

Does anyone know a good plumber in St Charles, Mo who can install tankless hot water heater?

Edward said:

I've always bought good quality appliances disregarding the cost because I figure it's worth it in the long run. Purchased a Rheem top of the line gas tankless heater two years ago and it has malfunctioned twice. It's normal for appliances to become defective, but the customer service is the worst. It has been covered under the warranty but each time the company tries to blame it on the venting system which was inspected by the city when installed. Both times has been an ignitor gone bad. It takes about a week by the time they admit the problem, ship it, and have someone replace it. If the problem persists, I'll invest in a Noritz, Rinnai, or Paloma which means more money out of pocket. To me customer service is the most important regardless of whose at fault.

Tim said:

Has anyone used a tankless water heater in a cabin. In the winter it gets down into the -20 below, so not sure if this would be a good idea ?? We shut the heat off for a couple of months also, when we are not going to be there. Would be looking at a propane tankless water heater also if anyone has good luck with them.

Tom said:

I am a Sure Comfort Tankless water heater rep. The BIGGEST problem with the tankless heaters is that the gas meter on a residential home CANNOT push enough gas to support the tankless heater AND all the other gas appliances. In every application that I have sized, every gas meter was too small. It is not just the size of the gas line, it is the size of the meter. You, or your contractor can call your public service gas provider and ask for sizing assistance. You can do it on line or on the telephone. The tankless heaters are made very well, but if it is not sized and installed correctly, you're dead. Most plumbers and heating companies CANNOT size, install or repair these units. Call a contractor who is a CERTIFIED TANKLESS WATER HEATER specialist. It will make a difference.

George Tavares said:

Beware, Rheem has come out with an electric tankless water heater, this is the same garbage as Titan which has huindreds of complaints, they only last about 1 year. Visit HOME DEPOT and see reviews and you will see what I am talking about.

Joy Perry said:

I'd like an aprox cost of a Noritz tankless water heater

C. Kennedy said:

Our Titan Tankless water heater lasted about 6 months worth of use. I would not recommend a Titan. Not sure tankless is worth the money and trouble. I have not seen any savings.

Tim said:

Bosch Aquastar does not support there product. Got harassed by their tech support people. My Bosch Aquastar 125 blp lasted only 6 years as the heat exchanger failed. The warranty says 12 years on the heat exchanger, but they fight with you to find any way to not honor the warranty. Go with another maker.

Not There Yet said:

Unfortunately I don't think tankless water heaters are quite there yet. I'll wait another five years and buy one when the technology is better.

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