Tankless Water heater

[Ronstar]

Well the warranty plumber showed up and replaced our water heater with the same kind we had - a 50 gal conventional electric. We grilled him with lots of questions - he isn't too fond of tankless or heat pump water heaters. Maybe his opinions are job security driven.

 

[FIREarly]

DW/DH are buying a new home with thankless water heater (this is new to both of us).

Will you please provide trusted URL(s) for how to maintain an electric tank tankless water heater?

Read through page 2 of this post and the other half is asking me to join them and walk the dog. If answer is after that will you let me know?

 

[Murph]

I replaced my gas hot water tank with a tankless gas unit about 12 years ago. We only have 1.5 baths in the house, but have had 3 people (including a teenage girl). We never run out of hot water, the unit has never given us trouble, and has only a small air filter we wash once or twice a year. Exception: it won’t run when there’s no electricity, and since there’s no tank you get no hot water during a power outage. In NE Ohio, that’s an infrequent problem.

 

[COcheesehead]

We also have a Rinnai. Had it for 3 years so far in our new construction home. Took getting used to waiting for the hot water ( especially because we live in the Northeast), but we like it. It’s electric. We like it. Doesn’t seem to be expensive to operate.

I recirculating pump would cure the wait for the hot water. We had both with and without. With the pump is better for us.

 

[ncbill]

I replaced my gas hot water tank with a tankless gas unit about 12 years ago. We only have 1.5 baths in the house, but have had 3 people (including a teenage girl). We never run out of hot water, the unit has never given us trouble, and has only a small air filter we wash once or twice a year. Exception: it won’t run when there’s no electricity, and since there’s no tank you get no hot water during a power outage. In NE Ohio, that’s an infrequent problem.

FYI there are units that use the water's flow to fire a piezoelectric igniter & so require no electricity.

Our local Boy Scout camp added the above (propane-fired) for hot water for showers at campsite bathrooms which have no electricity (pit toilets, sinks, & now showers via water from a large tank situated on a ridge above the camp)

 

[Retired Expat]

Who has a tankless water heater? Gas or electric? How do you like it?

Our current Rheem water heater (tank) sprung a leak today. 20 months after it was installed as a warranty replacement of the previous tank water heater that lasted 20 months. We've had around 8 water heaters in 28 years.

I think I want to go electric tankless. Only issue is that the tankless has a larger electric need, and right now my current water heater is wired to my generator panel, which is full. I'd have to move a couple circuits from my generator panel back to my main panel, making those circuits dark when the power goes out. Oh well, seems to me a few hours of electrical work now would make sense to avoid future tank leaks. / QUOTE:


Had one (gas) in an apartment we had a couple of years back. Didn’t like it They use a flow sensor to cut off the heat if the water wasn’t flowing so to get hot water had to open the tap half way. But that meant running more cold to not get scalded. And just a waste of water! In our house I put in a heat pump unit. In the summer it acts like an air conditioner and dehumidifier in the basement. Which was always damp with condensate before or needed the dehumidifier to run all the time.

Compared to the electric tank hot water heater we had before it uses about 25% of the energy we used to. Fully controllable from my phone so easy to schedule or shut down when not in use

 

[hotwired]

Options

I didn't note your location but i am in Maine. Primary hot water comes from an indirect"boiler mate" that cubes of the hot water baseboard boiler. But we just had a hybrid electric/heart pump 60 gallon backup put in 2 years ago and love it.

Logic: winter the boiler is running so it's efficient to use some of that energy to hear your water. Spring summer, there's nothing worse efficiency wise than using an entire boiler just to hear hot water so we turn a couple valves in may and November to switch over. So 2 ways to hear our water... All we need in a second well and we're zombie apocalypse ready, haha!

But I'd give serious thought to hybrid tank. Easy enough to find out cost per year vs gas / electric instany

 

[Surewhitey]

We have a Navian tankless and love it. It's gas and supplies our heat as well as hot water. Never a problem running everything at once. (2 showers, washing machine etc...)

+1 for Navian gas here. We needed a pantry in the ole 52' cottage... The location of the kitchen and bathroom is within 10' of the heater in the attic so no circulation needed. Has worked fine for 5 years now.

Water takes a while to get to the laundry in the detached garage though. You may want to get a mini unit for emergencies that just plugs into a 110 outlet. They work surprisingly well. Bosch makes a good one for <$200.

 

[Jimsim0225]

Should still be under warranty:

Rheem Water Heater Warranty Coverage
Series Length of Warranty ProtectionPlus Upgrade Extension Length
Classic 6-year limited tank and parts 10-year tank warranty
Classic Plus 8-years limited tank and parts 12-year tank warranty
Prestige 12-year limited tank and parts N/A
Marathon 6-year limited parts and lifetime tank warranty N/A

Who has a tankless water heater? Gas or electric? How do you like it?

Our current Rheem water heater (tank) sprung a leak today. 20 months after it was installed as a warranty replacement of the previous tank water heater that lasted 20 months. We've had around 8 water heaters in 28 years.

I think I want to go electric tankless. Only issue is that the tankless has a larger electric need, and right now my current water heater is wired to my generator panel, which is full. I'd have to move a couple circuits from my generator panel back to my main panel, making those circuits dark when the power goes out. Oh well, seems to me a few hours of electrical work now would make sense to avoid future tank leaks.


And of course I'd like the tankless to be a warranty replacement, installed by Rheem's plumber. I would supply the upsized electric.

 

[airbornesapper]

Installed a NG Rennai 160in up and running for 7 months...bought it from a local who decided not to install,...replacing a 13 year old NG Tank Water heater.

Great price on the unit...and Rennai doubled the warranty on registration.

Install was pricey and I shopped around.

Overall quite happy...if I hadn't bought this one...I would have opted for the recirculating versions.

Its working well and not much different to the old one...I'd do it again....So far.

Different story perhaps if only choice is electric...but I would still opt for a recirculating version either way.

 

[airbornesapper]

We have had a dishwasher, washing machine and two showers running on our NG Tankless mid-size unit...no problems at all.

 

[old medic]

You may want to get a mini unit for emergencies that just plugs into a 110 outlet. They work surprisingly well. Bosch makes a good one for <$200.

A buddy put a small 110 tankless under his shop sink and was surprised on how well it worked.

 

[ERD50]

A buddy put a small 110 tankless under his shop sink and was surprised on how well it worked.

That is surprising. A typical 110V/20A circuit would be 2200 watts max with zero margin, that can only heat 0.25 GPM from 70F to 105F. That assumes your water has come to ~ room temperature, which is probably safe assumption for water occasionally drawn at a sink.

https://gettopics.com/en/calc/water-heating-time

The ones I'm seeing require a 30A circuit, not common at all in the US. And get poor reviews:

https://www.amazon.com/s?k=110v+tan...UEHPJV1WX5&sprefix=110v+tankless+water+heater

I would think a small tank would make more sense. A small draw will heat enough water to wash hands, etc. Something like this gets much better reviews, and only draws ~ 10A, it could share a bathroom 20A circuit, or have it's own 15A circuit, but a hair dryer could push it.

-ERD50

 

[NW-Bound]

DW/DH are buying a new home with thankless water heater (this is new to both of us)...

Seems to me a "thankless" water heater is to be avoided at all cost.

Sorry, I could not resist.

If your electric plan has a demand-based rate, I suspect the tankless heater will cost more to operate than a conventional heater, unless you refrain from using any hot water during peak-rate hours. A tankless heater draws a LOT of power to heat water in a hurry. Of course I am talking about electric heaters, and not gas-fired ones.

Where I am, electricity in the summer costs 3x during the period of 2PM-8PM, compared to the rest of the day. Prior to having my DIY solar, I used a timer to switch off the water heater during the above period. The 50-gallon capacity was plenty to use during the off period.

The water heater is now run off the solar power, and I do want it to run during the sunlight hours to use up the produced solar power, instead of storing the juice in the battery and using it later. This is more efficient (less power loss), and saves wear and tear on the battery.


PS. By the way, many of the European Airbnbs we stayed at had a tankless water heater, with most of them running on natural gas. I could tell by the roaring flame when they turned on. I did not like them. The water flow had to be just right, or the water was too hot or too cold. This was despite the units trying to modulate the flame to match the heat production to the water demand. Maybe these were cheap units, I don't know.

 

[bobandsherry]

PS. By the way, many of the European Airbnbs we stayed at had a tankless water heater, with most of them running on natural gas. I could tell by the roaring flame when they turned on. I did not like them. The water flow had to be just right, or the water was too hot or too cold. This was despite the units trying to modulate the flame to match the heat production to the water demand. Maybe these were cheap units, I don't know.

Not sure why problem with modulating your water temp, but our new home came with gas tankless water heater and have not experienced any problem modulating. So maybe cheap or older style units, maybe just needed a repair or cleaning (tankless need to be flushed annually for best performance).