Problematic Tankless Models

Please post your experiences with any of our “not recommended” tankless products.  Post any questions or comments and you can also rate your current tankless model for others to view. When making your tankless purchase you must research the product thoroughly and remember that if a warranty sounds to good to be true, it probably is. If a tankless product says American or USA in the branding it is many times made in China. Many products offer lifetime warranties or other outrageous service claims but will change company names after a year or two and you will have an obsolete product.  As indicated in our article many tankless companies only last a year or two and vanish. We found that companies with a history, reputation and seniority in the industry are a good starting point.


  • Michael Best says:

    I really appreciate the info but what about gas models. I am looking for gas not electric. What do you recommend?

  • Chicago Plumber says:

    I was curious how tankless models would work in Chicago in the winter season. We get some cold incoming water during those times. Can a more powerful tankless model handle this type climate?

  • rusty escott says:

    marey water heaters there coustomer service is crap . slow to responed to emails , overcharge on shipping (oring) slow shipping , then ships wrong part buyer beware

  • OBP Milling says:

    I appreciate, cause I found exactly what I was looking for. You have ended my four day long hunt! God Bless you man. Have a nice day. Bye

  • Jeremy says:

    I was looking to buy a Marey tankless l p propane unit it is the model power GA16LP , sad to learn these reviews but they seem to be on the electric units,this unit is about 310 bucks and says to serve four baths,can you please steer me in the right direction,or let me know if this one is fine,and water pressure is always a factor this one claims to be around115 to 125 psi

  • Eric G says:

    Good site! I am still a bit leery of purchasing a tankless but this information has helped me greatly. I also like that the Titan is made in the USA and am not really interested in Chinese models.

  • ミュウミュウ 長財布 ファスナー says:

    Iam in agreement that many same tank less models are made in China by same factory but there are good ones made here

    • Maggi says:

      I’m back for a follow-up to my post of 28-may-2007. The short vesroin is that Bosch swapped my heater and now I have hot-hot-HOT water.The longer vesroin follows: I sent email to Bosch describing my situation (hot water at 6gal/min but no hot water at 2gal/min). They requested a bunch of info to create a file on me, which I supplied. I had difficulty with a couple of lines since I received the heater as a gift and could not verify the vendor. Also, my neighbor was a plumber and helped me install it. He has subsequently relocated out of the area, but was not that significantly involved in the installation other than sweating some copper pipe. I was instructed to call them with my plumber, who didn’t exist, so they could troubleshoot. They seemed interested in dealing with a plumber. I guess I couldn’t blame them. I’m sure most homeowners try to cheat on some of the installation and blame Bosch. That wasn’t the case with me but how were they to know.Frustrated, I went online for several weeks and finally was able to purchase a UEI c75 combustion gas analyzer on ebay. I also fashioned a manometer from some vinyl tubing and water with food coloring. Using a gallon container, I marked positions on the webstone bypass valve for 6gpm/4gpm/2gpm/1gpm. I went through the Bosch manual and service bulletins and took CO-2 measurements for the settings that I could. I also verified the gas pressure even though I knew it was not a consideration since the device worked at high flow. I even took photos of the installation and video of the behavior the device exhibited at water flow rates below 2 or 3 gpm. I packaged the entire thing into an email to Bosch and received a reply from one of their technicians named Bannon. He requested that I call him from the device. I did so and worked with him for a short time when he indicated that he thought the gas valve was malfunctioning. He was very good to work with. After giving him a credit card number for a deposit he arranged for a replacement to be shipped. The credit card was to guarantee I’d send the old one back.The new unit arrived and I installed it. It is much, much quieter and delivers hot water once the flow rate is achieved. I’ve had a couple issues. Since I live in Los Angeles and we’ve had record high temperatures recently, the hot water temperature has been very hot at low-flow levels since the water entering the device has been over 70degrees Fahrenheit. Also, one of my showers has very low flow (not sure why but it’s always been that way) so I have to turn on the faucet in the sink to get the minimum flow to cause the unit to fire-up. All things considered I’m pretty happy with the overall setup. I plan on installing an electric in series and some items to help with water-hammer.The UEI c75 combustion gas analyzer was really easy to use and provided some really cool info on the C02 levels and temperature in the vent pipe. It was over 500degrees Fahrenheit at the point where I was getting the best CO2 readings. Now that everything is working, I’ll put it back on ebay and hopefully get most of my purchase price back.Thanks again for your site. It has been a big help

  • Jerry (Flabowler) says:

    I truly wanted to send a simple note so as to express gratitude to you for all of the helpful information you are placing on this site. My time consuming search for a decent tankless model has been greatly helped by the information here. I just wish there was more information on gas models.

    • Romuald says:

      Please post a pic of your air intake coveorsinn, I am desparate. I live in Portland OR and have a bosh 635ES. I have had all of the problems listed above and more. I installed the first in 2006. Before Bosh would even care that I existed I spent untold hours proving to them that I installed it to their specs and even better. One and a half years later I installed my second water heater as Bosh finally after 100 s of calls and hours of troubleshooting and replacing parts sent me a new one. On the first one I changed temperature sensors 4 times, and the computer once. The new one has had problems too. One that I didne2€™t see above, but might relate to Chicago, is the condensation in my 3 long exhaust pipe was more volume than the condensation drain could handle and the paint on the exhaust collar blistered, cackle off and clogged the drain. In fact if you run it with the vent off you’ll be shocked at how much steam comes out of it.(energy efficient?) It turns out that Bosh has a new requirement that a second condensation drain be put in the exhaust pipe. (This was printed in a Service Bulletin long after I bought my 1st unit) They nicely sent me one. My original design didne2€™t include this, so of course it was a real pain installing it. I guess the problem is solved, my symptom before was the overflowing water from between the exhaust vent and the exhaust collar. I done2€™t have water overflowing now but the paint on the outside is blistering. I wonder whate2€™s happening on the inside. Bosh told me that the only thing that water dripping back into the unit my damage is to the gas valve, but that is e2€œnot likelye2€9d. For now I am fighting the whistling piece of shit. Apparently my neighbors have been putting up with it for years, though maybe only in the warmer months. Now that I am actively investigating it, it seem that it doesne2€™t whistle until its been running for about 7min. I wonder if it relates to water dripping back into it?Oh yeah one of the Boshe2€™s reasons my heater stopped working in August was that the water had to heat to at least 70 degrees higher than it came in at, however if the incoming water was warm the heater would shut itself off because it reached e2€œdangerous hot tempe2€9d. My first unit would just burn you and melt the pipes so cold showers in August are safe. Awwe2€a6e2€a6 August is coming again I wonder if that problem ever got worked out or if August ended last year and I could no longer troubleshoot it. In the mean time Rinnia has been recommended to me by plumbers, heating companies, and the local do it yourselfer heating specialty store.

  • Dan Willis says:

    I was just posting a comment for you on the Maxwell water heater, I purchased it from on online company on ebay and thought it was a good deal, after installing I found that it had poor output on pressure and couldn’t even run by bath. It stopped working less than a year after instalation. I would not recomend this company, no phone number could be found to call about a replacement.

    • Junie says:

      The hot water heater gets quite a workout in most home plumbing systems. Based on manufacturer’s suggested service life, the life expectancy of a hot water heater is about 8 to 12 years. Most plumbers will advise to replace the hot water heater if you need a repair around 8 years. That, of course, will vary with the severity of local weather, the unit design, quality of installation and the level of maintenance your unit has received. What is the life expectancy of an average tankless model.

  • says:

    I recently purchased a Marey Heater. I am in The Bahamas and of course the extra shipping costs and also the import taxes almost doubled the price for me. Well their installation video that is online does mention that a vent kit is needed, but the impression is given that the vent kit is one that can be purchased at ANY hardware store. Now I am learning differently. I am now being directed to a web site where I would need to buy a number of accessories to vent the system out which includes 2 45 degree elbows, 2 12″ straight piping and a weather cap for the outside end of the vent system. All items are of 5″ in diameter. The total costs of these extras that I was not told about $250.00 which is the cost of the heater itself before my shipping costs and import taxes. What a waste of money. This should be spelled out clearly for the customer before purchase. I am very upset that they do not even sell the parts but referred me to a website.

    • admin says:

      We have gotten some negative reports on the Marey units as you can see above. I am not sure which model you ordered but it sounds like a gas model if it required a vent. In the Bahamas you should go electric as 220-240 is the norm there. Most of your tankless models, like the Titan, will have most of the installation components needed with the exception of inexpensive valves and plumbing supplies.
      It is unfortunate that you had such a bad experience.

  • Peter Koyote says:

    I purchased a 16L LPG water heater from Marey, but didn’t get it installed until 90 days after purchase… When the unit proved defective, leaking internally, I called for warranty assistance… I was told by the operator that if you do not register this product within 30 days of purchase, Marey will NOT honor the 1 year warranty… Companies that only look for ways out of their obligations are not worthy of your business…
    Additionally, the controls on the unit do not operate properly… It is difficult to keep a consistent water temperature… While showering, you must often readjust your hot and cold faucets… and always be ready to jump outta the shower, just in case the water turn instantly cold when the heater shuts down for no reason whatsoever… You must shut off the hot water for about ten seconds in order to get it to restart.
    Overall, very unsatisfied with the Marey Tankless Water Heater and their manufacturer.

  • Fred Hatfield says:

    Hey I think these units are good but not as good as the Titan.


  • lou rall says:



    maxwell heater made by klimaire company burns out in less than 6 months

    I purchased a Maxwell brand heater (made by the klimaire company) tankless electric water heater model # MS150C2PSU 15kw 220V / 240V on EBay about 9 months ago. I installed the heater and began to use it about 3 months later. Unbeknownst to me the Maxwell heater was smoking probably a month of using it because my family and I would constantly smell an electrical burning scent in the air, but did not know where it was coming from. So the unit worked ok heating water but suddenly it stopped in less than 6 months of use and 9 months of ownership. I immediately tried to contact the manufacturer through their website where they have a contact us section. I filled out the online link and even tried to call them (but their PHONE NUMBER was disconnected) with no success. I then contacted the Ebay seller and told them about my situation they helped me by giving me another telephone number for the company which is; 800-978-5628 they answered the telephone with “HELLO” I was surprised and mostly confused because I thought I called the wrong number. After telling them that my unit failed so early and showed them the pictures of the tankless water heater, they acted shocked, but I don’t know how could they be, because more of their customers have been posting negative reviews about the same problem….UNIT NOT HEATING, burned plastic case (this entire unit is made from plastic) which could have BURNED DOWN MY HOME!!!! The Klimaire company sent me 4 pdf files that they told me to complete and to send them back. I completed them in about 25 to 40 minutes and sent them back, they contacted me in about 2 hours and informed me that they would be unable to honor the warranty because I (an unlicensed electrician) installed the tankless heater and so they cannot send me another one. I emailed them back explaining to them that in the State of OHIO, City of Cleveland….that we as the home owner can pull our own permits and install our own electrical and plumbing. I give them the City inspector’s phone number and license number…as the inspector’s job is to confirm that all is completed properly. I also told Klimaire that what they are doing is just an out to NOT their warranty and that I would not hesitate to share my experience with other’s on and offline. They will not respond to my messages any longer and so in closing I am warning anyone who is looking to purchase a electric tankless water heater, to be careful and know that Klimaire company have a history of their tankless water heaters breaking, catching fire and not heating. They appear to not want to honor their written promise to replace the heater should the unit stop working.

    • admin says:

      Thank you for your comment. We have receive many similar complaints and it is unfortunate you had to experience this.

  • Thomas says:

    Just bought a Marey electric tankless eco240, 24kw. Has 5 year warranty. What are your thoughts in this product. I also have 3 full bathrooms, dishwasher, washing machine. Although I will hopefully never have the need to supply all if these at once I would like to be able to supply 2 showers and maybe a sink at once. The incoming ground water is between 60 – 65 degrees and about 50lbs of psi. Do you recommend something different or more. Thanks any help is appreciated.

    • lu ralls says:

      Hello and thanks for your question. First I must admit that I am not an expert with determining the type and model however I personally believe that rating should suffice. Now as for the brand, I am not sure but you may want to research a bit more on that brand because the internal appears to be identical to the Maxwell tankless heater that has failed on me in 8 months. Maybe they are from different companies but I would try to check into this a little more because if it is from the Klimaire / brand…then you are most likely going to have a problem with the unit and DEFINITELY with the company & warranty.

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