tankless water heater

[mckitterick]

Hey, home-owners -

Do any of you have a tankless water heater? What do you think of it? How much did it cost to install?

When I bought the house, the inspector said that the existing hot-tank water heater was at the end of its useful life, and now it's four years later. Rather than replace it with another "keep the water hot all the time" type of heater, I'm considering one of the tankless units. They're much cheaper to run (only heats when you request hot water), more compact, and pollute less. They're not cheap, but qualify for a $300 tax rebate.

Any thoughts or recommendations?

Best,
Chris

Comments

[professormass.livejournal.com]

I did a lot of research into replacing the thimble-sized hot water heater we have in our new place, and what I discovered is this:

Basically, you want to buy the more expensive units, and make certain that you've got Pyrex pipes. The older pipes, apparently, can burst when the hot water hits them from the unit, because of the rapid change between hot and cold.

Also, the cheaper models seem to break down a lot more. The one I was looking at was $1200 Cdn., and the installation (including replacing the pipes) would've cost me about $600 Cdn.

Let me know if you want a link to the unit I was looking at, and I'll dig it up.

[chernobylred.livejournal.com]

Pyrex? Glass pipes?

[professormass.livejournal.com]

See my comment below. It's the drugs. Really.

[mckitterick.livejournal.com]

Pyrex? Seriously, you need non-expanding-glass pipes? Do they even make those? Or is this hyperbole?

[professormass.livejournal.com]

Sorry, I'm totally smoking crack. I meant PEX piping.

It has three of the same letters!

Stop looking at me that way.

[chernobylred.livejournal.com]

=D

[mckitterick.livejournal.com]

*g*

That makes more sense. Though I started getting excited about having Pyrex pipes. Wrapped in buckyball insulation, too.

[stuology.livejournal.com]

Here are points from when we were trying to decide to go tankless or not after ours started leaking. Since we decided that the >$1000 cost after installation wasn't worth it for a house we won't be in long, this is just our research, and not experience.

--Installation costs were a lot more than for a tank one. There are fewer people who know how to do it.

--Probably part of that cost is the fact that the gas line and venting has to be increased for tankless. It may depend on your house.

--Repair for tankless is more expensive because parts are more expensive and they are more complicated to fix than tanks.

-This doesn't relate to your case I'm sure, but it they work fine if you keep water flow in a certain range. If you go below that range, they don't heat as well, and if you use a lot, the water cools downs. The smaller capacity ones are also prone to water temperature fluctuations when using multiple hot water sources more than tanks. To ensure consistent hot water expectations, you have to get the large capacity ones. This was an issue for me since I have 4 adults and two kids--both with diaper washing that needs hot water. The larger capacity ones are really expensive.

[stuology.livejournal.com]

Oh, I also forgot, even though this wasn't an a big deal to me since it would be a rare occasion.

--They are more prone to freezing. However, it will be indoors (they do have outdoor ones), and you would only have to be concerned should you lose electricity in the winter for any amount of time.

[mckitterick.livejournal.com]

Interesting point. I was considering an outdoor unit for simpler exhaust and space-savings, but leaving it inside near the furnace (as now) seems a smarter way to go.

It depends on a few things, naturally

[bodandra.livejournal.com]

Those kinds used in Europe - and work well. The only bad part is - how long does the water have to go before it is used? In Spain, the woman who housed me had one bathroom; the water heater was in the kitchen (so hot water for the sink / dish washing was immediate - to get to the bathroom? about 15 minutes)
I took a lot of cold showers there; but guess what? I learned to enjoy it (most of the time). Hoe long does it taker for the hot water to reach your bathroom now?

Re: It depends on a few things, naturally

[mckitterick.livejournal.com]

That must have been a point-of-use heater! Or else you were staying in a vast villa, or they had a small unit and were using hot water elsewhere at the same time? Fifteen minutes seems crazy, like something was wrong. I've read reviews of them and never heard of this happening with a whole-house tankless heater.

All of my hot-water points-of-use are within about six feet of the heater. Even so, sometimes it takes a minute or so to get water at full temp.

[bodandra.livejournal.com]

It was a personal flat in Barcelona. I'd guess that it was about 4 yards from the heater in the kitchen to the bathroom, but i have no idea how long the pipes were between the two - the water had to move a long way.

[affreca.livejournal.com]

Like Bodandra, I've only used them in foreign countries, not tried to get one. I had a tankless water heater when I lived in Japan, and loved it. Simple, more control over the temperature and efficient. Good luck.

[secritcrush.livejournal.com]

Here's the most important line in the spec:

Water Flow Rate: GPM at 77 Degree Rise Max: 3.1 GPM

That's how much flow rate you can get in the winter time, getting you to 117 degree F - If your place is older (basically pre-1992 bathroom), the flow rate from your shower could be on the order of 5-8 gallons per minute. And that 3.1 gpm might not be enough to get you a decently warm shower. (Typical shower temps are around 110 deg F.)

Tankless heaters are good, but not if they can't service your demand.

[mckitterick.livejournal.com]

Thanks for the tip. Looks like I would want the bigger unit at 4.3 GPM; I've installed low-flow shower heads, so that shouldn't be a problem as long as it doesn't use more than the heater puts out.

[secritcrush.livejournal.com]

Well if you put in low flow shower heads (typically 2.5 gpm) and you don't expect to run more than one appliance at once, you are likely fine with the smaller one. It's probably a good idea to do a bucket test for your main fixures before you buy (that is, time how long it takes to fill a bucket of known size so you can calculate the flow rate.) While you can fiddle with storage heaters to get a bigger flow rate for a shorter time, with instantaneous you are stuck with what you've bought during colder months (and since Kansas gets the cold, I think being optimistic here is not a good warm shower having plan.)

[bellanorth.livejournal.com]

We have one, and 0verdrive installed it so that wasn't a concern. You should ask him about it. I think it works well, and it's a great space saver.

[mckitterick.livejournal.com]

That's hopeful: So the pipes haven't exploded, and it hasn't exploded, either. Is it gas or electric?

[bellanorth.livejournal.com]

No pipes exploded or other damages. It's gas, installed inside. Proper venting took some time to install given that he did so in the rain, but I doubt you'd have that issue right now. Plus your current heater is so centrally located that your delay at the faucet would be minimal. For us, the heater is at the far end of the house and it takes a good 45-60 seconds to finish the pipe maze, so for a quick wash of the hands I no longer attempt hot water. Showers, dishes, etc. take a minute to warm the water but there is no concern with amount once the hot water reaches the faucet.

[mckitterick.livejournal.com]

Good news, thanks!

[desperance.livejournal.com]

Speaking foreign here, and I don't know what the differences are: but I grew up with one, and loved it (as much hot water as you want, when you want it, and not otherwise? What's not to love?). Since then I've been living with tanks, and I dislike them extremely: not enough hot when I want it, and paying for it all the time whether I want it or not. But I can't afford the replumbing. If you have to replumb, then go tankless...