7 Mistakes When Installing an On Demand Water Heater (tankless water heater)

Jim always recommends on demand water heaters but make sure you don’t make these mistakes when installing one or buying one.

We hope these common mistakes save you time and money when purchasing and installing a tankless or on demand water heater.

Reasons you are running out of hot water:
00:00 intro
00:21 not owning one
01:40 where is the water softener
02:58 small gas line
03:52 too small of a heater
04:22 Indoor or outdoor water heater
05:21 isolation valves
07:15 thinking you can’t install it

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#plumbing #waterheater #tanklesswaterheater

[SuedeHTX]

Love this guy, he's the Scotty Kilmer of plumbing. Thanks for all the great advice Pop.

[KLlife]

Mr Grumpy Plumber thank you for saying we can do it because us DIYers thrive on channels like this. Beers to you!!! 😂

[mikepoint]

Great advice on the large on demand, after speaking with the technician he mentioned to me the price difference is peanuts, so big or go home . Cheers 🇨🇦

[phillyfathead]

Yo the grumpy guy is not following the script 😂🤣😆, great video!

[retired]

Thank you for the quick reply. You're a good man Mr. Grumpy!

[grandpied]

I like grumpy people and grumpy plumbers are even better. Greetings from the west coast.

[anthonyhitchings]

We have a 1.5 year old Rheem Super High Efficiency indoor tankless, its working well so far. Our "closet" has a great supply of combustion air so I am (finally) going to run a single exhaust pipe (2" PVC) up through the old (large) roof vent opening. Our condensate is alkaline, we do not need to treat the condensate with lime. We included the extra valving for flushing. This allowed us to use a simple condensate pump to push the condensate to a nearby utility sink. It replaced a Bosch non-electric tankless unit that lasted well over 25 years. The big thing was using Sharkbite fittings when we redid all the piping (from a prior hack job). This new heater weighed over 80 Lbs empty!!

[TheCrawler]

Great video. I initially considered going to the largest capacity tankless unit I could find. But as I looked into it, I found that a larger unit would increase the installation cost dramatically over a more modest sized unit for my 2 bath house. I also looked into other factors that influenced installation issues, so be sure to consider the entire installed system cost, not just the cost of the heater.

I covered my selection process in a video titled "My Tankless Water Heater Selection Process". I think my tankless unit has already paid for the added cost of it, over putting in a new tank type heater, since it was installed in 2017. In fact, with this "California Climate Credit" program, I've not paid a gas bill since 2018.

One note for folks that live in affected air quality districts in California (SF Bay Area for sure), there's a proposed regulation banning the sale of new gas fired water heaters of any type starting in 2027. So if you're thinking of installing one in the future, keep that in mind. I plan on purchasing a spare unit, just in case something goes wrong with it 10+ years from now.

[gusty]

I have heard a lot of people complain about the noise. They are not loud but they still make noise that most people don't expect.

[Slick.]

I love the savings on gas it has saved me 250 gallons basically a one tank a year instead of two . The greenhouse people will love this less emissions 🙂👍

[Spookdog]

I have no problem with on demand water heaters and see the benefits but living in earthquake country I appreciate having a tank water heater as an emergency water source.

[robertwoodworth]

In 2006 I installed a noritz 1st line of commercial tankless heater from plumbing supply $900+ $250 for double wall stainless venting, after 8 yrs copper heat exchanger started leaking. Ten year warranty on exchanger but would’ve had to pay labor. So I bought a new noritz heater with stainless steel 2 stage burners (latest and greatest) $2000+ paid a recommended plumber $500+ for install. After 3 yrs internal recirculating pump started leaking. Pump covered, paid same plumber $300 labor. Plumber normally sells navien tankless, said I wasted my money on internal recirculating pump. Said I didn’t need it. I took my water softener out 6 yrs ago because I had drain it out my yard which killed the grass. Installed scale watcher descaler . This really does work, but had-to clean aerators quite a bit until the last yr or so. I also have a spin on scale filter before the heater. I’m on a well and I don’t want soft water on my drinking water but would it be a good idea to install a small Water Boss softener before my tankless heater? I do have flush valves on the heater (flush once a yr) . My problem is there’s not much room in my utility room but I do have a condensate pump on my furnace that also is gravity fed and taped into my tub trap. One other question, when getting a shower the water will heat up and cool down (you can here the burner’s kicking on and off and you have to make adjustments all the time and it’s aggravating. Does it abound 50% of the time. Someone mentioned it might help to clean out my showers balanced valve? I hope all this makes sense, thanks

[retired]

What are your thoughts on the Navien combo unit for hot water domestic supply and hot water for the heating of the home's baseboard heating? My daughters house had one (about 10 years ago) and the heating of the house overrided the domestic hot water usuage. If the heat was on in the winter and you wanted to wash the dishes, you very often had no hot water until the heating of the house was satisified.

[thenexthobby]

Hi Jim, how do you feel about this supply level?

--> All pipe diameters mentioned below were measured externally and then I subtracted 1/4"

[edited]

My gas meter It has a 1" outlet supplying 3/4" to the house (there's a reducer coupling outside, at the meter.) It's apparently a 250K BTU meter (which is fairly standard, I'm told). What are my chances it can actually supply more?

existing: 80K furnace + 18K wall heater + 38K water heater = 136K
new options:
80K furnace + 18K wall heater + 160K tankless = 258K
80K furnace + 180K tankless = 260K
80K furnace + 199K tankless = 280K

I deleted the other text I had about the appliances. A pressure drop calculation would need to be done, but I think the existing line to my existing tank (a 3/4" line) is about 40ft from the meter.

I recognize the number of fixtures a tankless can supply is influenced by inlet water temp.

[rayjackson]

Im a contractor and I have one in my house. The only draw back is you need to run about 2 gallons of water to just wash your hands before it gets hot.

[JMSobie]

Thanks to you, I've started saying, "If you don't believe me, ask your dentist...."

[FurrKnight]

My current NG water heater is a standard 4-year-old one but since I'm doing a remodel and after this video I am seriously considering going tankless as the updated shower is double the size and will have dual shower heads and wands on opposite sides + a bench and all the walls will be porcelain tile, I want to make it into a spa-like experience and never have to worry about hot water running out. My question is: The current water heater is inside the 2 car garage, this is a one-story house, the vent of the current water heater was annexed to the old HVAC (replaced with heat pumps) exhaust and is (metal). Is it going to be really expensive to make the switch? Thank you for the video

[caseyhartman]

I'm considering getting a tankless water heater to free up space in my garage. I am concerned about the noise level since it would get installed on the common wall for my bedroom.

[ChalkySac]

Nice video. Thanks for taking the time to share with us. I have a question I can not seem to find the answer to. I have an existing old powervent water heater that has gone bad and I am installing a Rheem tankless. I am installing it in a open basement. I plan to use the existing 3in PVC vent for the exhaust but the exterior wall is 40ft away. Do you know if it is ok to draw the air from the basement? Or do you think it would cause issues? And if I have to run a intake pipe does it have to be the same length as the exhaust? I am not sure how long the existing exhaust pipe is because it goes up through a few floors above.

[fred]

We have an electric hot water heater. Do not have access to gas. Have one in florida. Love it. Bought one for northern home. Too small. Need to upgrade.Brand suggestions?