DawgTalkers.net Forums DawgTalk Everything Else... Tankless hot water heaters?

So one of my hot water heaters is leaking, time to replace it. I’ve got 2 50 gallon heaters (electric) and am considering going with a tankless. I’m not sure if both water heaters feed the entire house or if one is for the mother in law section and the other for the main house. I can’t really tell by following the pipes as they seem to go in both directions (towards MIL suite and main house).

If I can replace both with a single tankless that would be optimal and I can convert to propane if necessary.

I’m going to be calling a few plumbers next week, but was wondering if anyone had any experience with these. Thanks!

I have one and like it. Mine heats 5 gallons per minute. While I never tested it, I was told I could run every faucet in my house and never run out of hot water. It does take a few minutes for the water to heat up after turning the water(it's not instantly hot as some people think). Only downside I encountered is no hot water if the power goes out. Always had gas tank growing up, so it was one of those things I didn't even think of until it happened.

I researched them alot, and talked to our plumber about them.

He said, and my research says they are well worth it over time, but that gas is the way to go. As squires said, in case of power outages, the electric ones are no better than a tank.

My neighbors installed a propane tank and a tankless water heater, and after the hurricane during our week long power outage, we had the luxury of using thier shower to have hot showers.

Even on a hot day, a cold shower is only so refreshing before it becomes annoying.

As far as finding out which does what of your 2 tanks, shut off the water supply at the tank and go turn on hot water in the main house and go listen to the tank to hear of it is refiulling as it empties, then repeat for the MIL suite.

Do you have a house backup generator? These can be a load. Relatives of mine have these with small families. Love them!

I had one and I didn't like it. It ran off gas.

It's better when your ground water is not cold.

Summertime i always had hot showers. Wintertime though, my water never got very hot.


Now mine was like 15 years old, so maybe it was time to replace it. But i didn't go tankless again. I went tank water-heater. Never had a cold shower again. Unless my wife and i were both showering at the same time with both showerheads going for like 15 minutes.

But we didn't get a very big tank.

We have one and love it... only issue is a couple of our faucets it takes awhile to warm up... worst is we have an island sink in our kitchen that takes forever to g t hot... but my shower gt s hot right away and stays hot for as long as I want to shower,,,, love it...

I do not yet... There are not a lot of gas lines around here, so if you want gas, you have to install a propane tank.

Luckily I live down the street from a Hyatt resort that had gas lines brought in, and th egas company has recently offered to bring the lines into our development, so once that happens I will be adding a whole home generator, but will also switch to gas hot water, as well as put in a gas fireplace.

Got a real plan. Good luck with all this. Saving up for some kind of generator for whole house. Seems dumb until you need it.

The bigger the tank and the more insulation the more money you save. Build a nice extra insulated closet around that insulated 100 gallon tank and you won't have that big a bill for it.

Big tanks have high thermal mass so they don't lose heat as fast and because they have large volume you can actually let yourselves enjoy your shower and take your time.

Lowes sells and installs them for easy peasy. Pay the extra for the thermal insulation blanket. It saves a ton of money.

Turn one of the water heaters off, wait a little while, then walk around and see where you still have hot water.

Since your water heaters are electric, you may already have enough amperage pulled to run tankless but that is where one of my friends got burned, he had the plumber come to do the tankless and didn't realize he needed more power, ended up spending close to another $1000 to get an electrician to pull the right power.

I looked into getting one since my water heater (gas) is nearing the end of it's useful life. My problem is that tankless have to be vented differently, they can't use a standard water heater vent. It would have to be put in a different location, all of the electrical and everything would have to be moved. Cost would have been prohibitive and I would have had a vent pipe running up the side of the house.

I am a fan of tankless, just make sure you have ALL of the questions answered before moving forward. Plumbing, gas, electrical, venting, etc.

DC is right, most electric tankless require a 220 volt circuits to run each of the heating elements. And most whole home tankless have 2-3 heating elements. So you would need 3 220v circuit run to the heater.

As well as venting.

When my gas tank decided to die, I replaced it with another gas unit. If I lose power, I at least want to be able to take a hot shower, by candle light if necessary.

Thanks for all of the replies! After doing some more research and pricing the tankless seems cost prohibitive. I'd need to run a gas line, which I wouldn't do myself. I can replace the electric ones pretty easily without a plumber I think so I'm just going with what is there now. I've never run out of hot water and my manual backup generator runs the hot water circuit. Of course, a wi-fi enabled one will be purchased so I can tie it into my home automation

I did determine both tanks feed the entire house, didn't pay attention to the in/out when I looked the first time, but one tank has the cold coming in, the hot out on that tank is connected to the cold in on the other and then the hot out is on that tank for the whole house.

Thanks again Dawgs!

So tell me....why do you need 100 gallons of hot water? I don't think you have 5 daughters.

8-seater hot tub?

It's what was in the house when I bought it so just replacing with what was there. The house has a mother in law suite, actually, it's a teenager suite at the moment as my son has taken it over so probably why there are 2 heaters. 2 dishwashers, 2 washing machines, 2 kitchen sinks, 3 showers, and a jacuzzi tub for the whole house. The basement is finished and I plan on putting another full bathroom in there at some point - it is roughed in with studs and electric, just needs drywall and fixtures.

No hot tub yet Dave Been thinking about it though.

I got the 2 water heaters replaced yesterday evening - never done it before but it was pretty straight forward, took about 3 hours to do the 2. Hardest part was getting the new ones down the basement and the old ones out.

I also discovered that the leaking one was not even heating the water, when I drained it, it was room temp. The water is A LOT hotter coming out of the taps now as 1 heater was heating all of the water, the other was basically a holding tank.

8-seater hot tub would have it's own in-line water reheat.

I had a buddy call me one day a few years back and ask me to come help him get his water heater out of the basement, he and his father in law had been struggling with it for hours. So I showed up, drained 20 gallons of water from it.. and it became much easier to move.

I had one in my rental that finally died about two years ago. I say finally because it was born in the 60's and had a tag that said "Cleveland Glass Co" or something to that effect. It worked so well for so long that I decided years ago it wasn't leaving til it croaked.

Dumb thing still weighed about 275 after it was drained (I suspect much of the weight was mineral build-up). Two guys and a dolly, bottom guy stepped on the same step the dolly was on and broke the step! Took the scrap guy, his son and me to get it into the bed of his truck. The just don't make 'em like they used to.

An 8 seater is also far more than 100 gallons. I have a 4-5 seater and it’s 350 gallons. And you’re correct, they all have built in heaters.

Ha! Mine were definitely empty