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alligator · Oct 22, 2006, 03:53 PM

Anyone have a tankless water heater? How well does it work?

Our water heater is leaking water down our floor drain, and I'm considering getting a tankless design to save space in our cramped laundry room.

We have 5 people (two adults, three kids) in our family, and a 1800 square foot house (two baths).

I've already read about how they work, but I'd like some real life recommendations and opinions.

The Godfather · Oct 22, 2006, 04:03 PM

Check if the electrical wiring for the old tank will be good for the tankless W.H.

They use more power (thus the need of a fatter wire), but for a shorter time. All-in-all, they may save you money on the electric bill.

voodoo · Oct 22, 2006, 04:07 PM

I use a tankless gas water heater. Works like a charm with up to two taps running at the same time. Works better with one.

It takes little space and draws gas from a tank, so I have to change tanks every now and then.

V

mitchell_pgh · Oct 22, 2006, 04:15 PM

How big is your house?

I guess the trick is that you only have a finite amount of heat, so if 2-3 people were taking showers or running the dishwasher, etc. you might have problems.

Also, many people choose to keep their regular water tank (not heating naturally)... to bring the temperature of the water up a bit before entering the system tankless system.

Spliffdaddy · Oct 22, 2006, 06:41 PM

For a large family the standard 40-50 gallon water heater isn't terribly inefficient. Since yours is near death, I'd suggest replacing it with a high-efficiency model. Water heaters use about 25% of a home's energy requirement. I'm assuming your current heater is electric, not gas. Gas used to be less expensive than electricity, but in most places the price of electricity has not risen nearly as much as gas.

The 'demand' type water heaters are very efficient (90+%), last longer than standard tank heaters, and cost at least twice as much. You need to have an electrical circuit that could handle 28KW in order to oprate a 'standard' (3GPM @ 65F temp rise) on-demand heater. That's roughly 40-45amps. It's doubtful that your current water heater is wired for more than 30amps.

I haven't checked the prices of 'demand heaters' lately, but I'd guess you're looking at at least $600 for the unit plus installation - AND the cost of upgrading the electrical circuit to operate the heater. Copper prices are outrageous right now. You'll need 3-conductor 8gauge wiring...so ideally you want the heater to be close to the electrical panel - and the heater close to the bathroom plumbing.

Me? I'd spend the $325 for a high efficiency 40-50 gallon standard tank heater. It would take a long time to recover the $1,000+ cost of the tankless model.

imitchellg5 · Oct 22, 2006, 07:30 PM

We got a new Whirlpool water heater last winter... it was about $315. It was very nice. It's 45 gallons and puts out instant heat.

The Godfather · Oct 22, 2006, 07:39 PM

Don't you guys think all water heaters waste way too much energy? They make water scolding hot, and you have to mix it with cold water to have a pleasant shower.

Any temperature-programmable heaters around there? I would still like real hot water for my laundry and my dishes.

andi*pandi · Oct 22, 2006, 07:44 PM

we have on-demand, and the only time I've ever noticed the hot water running out is if I try to fill up the tub on full blast. Back-to-back showers, laundry, dishes, no problem. Ours is very old though.

alligator · Oct 22, 2006, 08:17 PM

Our house is a medium size (1800 square foot) house. We use up the water in our current water heater after four showers. We now have five people (although one is a baby).

I'm looking for two things - one, to save space in an already tight laundry room, and two, efficiency over the long haul.

We currently have a gas water heater. I'd like to do right by the environment with this one. Do I still need heavy gauge wiring if we go with a tankless GAS heater?

Oh, and we only have 100 Amp service that's already maxed out.

Andy8 · Oct 22, 2006, 08:18 PM

Most modern apartments here have mini gas water heaters in each bathroom, which you can set the maximum heating temperature on. It is very efficient and instant hot water when required, while also takin up the minimum of space.

G4ME · Oct 22, 2006, 10:03 PM

Originally Posted by alligator

Oh, and we only have 100 Amp service that's already maxed out.

Ouch, that sucks.

Umm look on the specs of a gas instant heater, but my guess would be you would be fine with the same wiring as you don't need the current to heat the water.

Spliffdaddy · 10:32 PM

Originally Posted by alligator

Our house is a medium size (1800 square foot) house. We use up the water in our current water heater after four showers. We now have five people (although one is a baby).

I'm looking for two things - one, to save space in an already tight laundry room, and two, efficiency over the long haul.

We currently have a gas water heater. I'd like to do right by the environment with this one. Do I still need heavy gauge wiring if we go with a tankless GAS heater?

Oh, and we only have 100 Amp service that's already maxed out.

You don't need any wiring at all for a gas water heater. Your 100amp service wouldn't be adequate for a electric on-demand water heater.

I think you need a 3/4" gas supply line for a on-demand gas water heater. Don't quote me on that - but make sure you check before you buy. (That's for a natural gas unit. LP gas pipe sizes are different - usually smaller. LP gas means you have a big tank outside)

PS, a 200amp electrical upgrade would only cost between $1500 - 2000. You would recover that cost when you sell the house - even if you didn't need the extra capacity for anything.

KeyLimePi · Oct 23, 2006, 06:32 AM

Odd that you would start this thread. I couldn't get the pilot light to stay lit on our hot water heater this weekend and had to call a plumber. He talked at length about the new tankless hot water heaters...said they seemed very convenient and efficient. He said that you could set the unit to heat the water to a pretty precise temperature, so some houses were having multiple units installed (e.g. one for the bath, one for the kitchen).

Anyway, he said he'd seem some and that one company (Renai??) was about the best, particually if you have a well (which we do).

Gamoe · Oct 23, 2006, 06:40 PM

I'd recommend against it, alligator, based on what I've heard from our electrician. They are convenient, but they don't seem to work well in a big house, where you need more units to keep the water heated and they use a lot of electricity.

Mastrap · Oct 23, 2006, 07:04 PM

Tankless gas heaters are the norm in the UK. While living there all of my homes, from apartments to houses, had them for both heating water and heating the house using radiators. Never any problems.

Love Calm Quiet · Oct 24, 2006, 08:40 AM

They may seem new to U.S. consumers, but Aussie immigrant friends told me 20 years ago how great it was to have instant heat from their Natural Gas heaters. As I recall, there'd be a unit near every hot water need. And these are average Joes... not wealthy homeowners.
It's been the standard there for decades (NG, not electric).
I'm thinking they're pilot-free -- meaning they use NO energy when you're not needing to use the hot water.
It'll take a while for U.S. mftrs & builders to have enough experience to have all the kinks out... and for the production (and competition) to ramp up enough that price comes down.

Dork. · Oct 24, 2006, 08:58 AM

Originally Posted by The Godfather

Don't you guys think all water heaters waste way too much energy? They make water scolding hot, and you have to mix it with cold water to have a pleasant shower.

Any temperature-programmable heaters around there? I would still like real hot water for my laundry and my dishes.

Our water heater (traditional natural gas, 50 gals) has a temperature setting right on it. We keep it low since we have a toddler in the house, and have no problem with laundry or dishes.

SirCastor · Oct 24, 2006, 09:10 AM

Originally Posted by Love Calm Quiet

They may seem new to U.S. consumers, but Aussie immigrant friends told me 20 years ago how great it was to have instant heat from their Natural Gas heaters. As I recall, there'd be a unit near every hot water need. And these are average Joes... not wealthy homeowners.
It's been the standard there for decades (NG, not electric).
I'm thinking they're pilot-free -- meaning they use NO energy when you're not needing to use the hot water.
It'll take a while for U.S. mftrs & builders to have enough experience to have all the kinks out... and for the production (and competition) to ramp up enough that price comes down.

I would guess that the technicaly end of it would come a lot sooner than the other parts. There are some politics involved that mirror the oil company/alternative fuel vehicles situation. A large change in technology means that someone stops making a lot of money, and that usually slows down advancement.

OldManMac · Oct 24, 2006, 10:24 AM

Tankless heaters have been the norm in Europe for many, many years. I have an electric water heater where I'm currently staying, and I turn it off completely unless I'm washing dishes. When I get my own place again, one of the first things to be replaced will be the water heater, unless it's new of course. I never could understand the concept of heating water and then letting it cool down and then reheating it, just for the sake of convenience. We could eliminate our need for ME oil overnight if we really wanted to, but in our self-important culture, it's more important to focus on ourselves, no matter what the cost.

Goldfinger · Oct 24, 2006, 10:38 AM

Originally Posted by alligator

Anyone have a tankless water heater? How well does it work?

Our water heater is leaking water down our floor drain, and I'm considering getting a tankless design to save space in our cramped laundry room.

We have 5 people (two adults, three kids) in our family, and a 1800 square foot house (two baths).

I've already read about how they work, but I'd like some real life recommendations and opinions.

I feel your pain. One of our boilers leaked last weak and now the ceiling in my room and a wall are full of water. Paint flaking a bit and the bits coming from the ceiling. Thank god the insurance covers it. We need to have two boilers in our house. According to the plummer those instant heat thingies wouldn't cut it in our house (we wanted to switch as well). So make sure to get a good plummer who knows what you need. Also make sure you have one of those "expansion canister" things (don't know the term in english, surge tank ?) they'll prevent them from ever leaking again.

starman · Oct 24, 2006, 10:56 AM

I hate it when water heaters don't tank you. They're so ungrateful

nredman · Nov 22, 2006, 07:48 AM

i need to pick up a new water heater - any suggestions on brands? we just got into our house - older house and old old water heater from 1972 - will be hooking up a new one this week sometime
'

talisker · Nov 22, 2006, 09:57 AM

Originally Posted by Mastrap

Tankless gas heaters are the norm in the UK.

That's true, but I wish someone had told that to the builders of our house, which is only about 6 years old. It's got a boiler that looks exactly like a "combi" tankless boiler, but isn't.

It feels incredibly wasteful to have our hot water heating on a timer, and a tank sitting full of hot water that we may not necessarily use. And it's incredibly annoying if you do run out. Also the tank takes up a substantial amount of cupboard space.

We may have to change it.

indigoimac · Nov 22, 2006, 10:35 AM

We had a Professional series Ruud 40gal natural gas water heater put in a few years ago after a 30gal one decided it would be a piece of crap.

Anyway, it's been great, it's not efficient at all (or so says the sticker on the front) but it's silent and I have yet to run out of hot water, even w/ people taking showers while the washing machine and dishwashers are going.

Mastrap · Nov 22, 2006, 10:41 AM

So you bought a piece of equipment despite it being:

a. expensive to run and
b. hard on the environment?

residentEvil · Nov 22, 2006, 10:45 AM

wtf?

it was on the shelf to buy...

maybe you should blame the manufacturer.

Spliffdaddy · Nov 22, 2006, 11:10 AM

So you bought a Mac despite it being:

a. expensive and
b. hard on the environment?

vmarks · Nov 22, 2006, 11:22 AM

Originally Posted by The Godfather

Don't you guys think all water heaters waste way too much energy? They make water scolding hot, and you have to mix it with cold water to have a pleasant shower.

Any temperature-programmable heaters around there? I would still like real hot water for my laundry and my dishes.

I actually prefer cold water for my laundry. It comes just as clean and the heat sets stains anyway.

residentEvil · Nov 22, 2006, 11:55 AM

you don't need "real hot" for laundry; use cold.

as for dishes; dishwashers contain a heating element that heats the water (no mater what the temp of the water it is coming in at) to the manufactures desired heating level to clean the dishes. and water heaters do have temperature control; usually 3 settings (vacation, normal, hot) or actual temperatures (from around 100 F to 132 F...or so)

i keep mine on vacation setting actually; and never had a problem with the dishwasher or taking a shower. granted, i like really hot showers, but i have adjusted. i'll go use my sauna for when i want to really be warmed up

Mastrap · Nov 22, 2006, 01:53 PM

Originally Posted by residentEvil

wtf?

it was on the shelf to buy...

maybe you should blame the manufacturer.

Of course. And to hell with personal responsibility.

Nicko · Nov 22, 2006, 03:39 PM

I was going to suggest a solar powered water heater...then I realized you're in Minnesota

indigoimac · Nov 22, 2006, 04:17 PM

Originally Posted by Mastrap

So you bought a piece of equipment despite it being:

a. expensive to run and
b. hard on the environment?

If you're referencing me, I didn't pick the water heater, it was an emergency install(I believe it was even a Sunday) and that was all he had that small(40 gal). From what I've been able to tell it's cheaper to run than the old one and quite frankly natural gas is pretty cheap here as is electricity.

As for the environment, we might as well stop using water, heating it w/ clean burning natural gas is not making the problem significantly worse.

Hugi · Nov 23, 2006, 03:23 PM

Originally Posted by Mastrap

So you bought a piece of equipment despite it being:

a. expensive to run and
b. hard on the environment?

I read your sentiment, but doesn't the same apply to our Macs?

alligator · Nov 24, 2006, 09:17 AM

The person I called to install a tankless heater said it couldn't be done due to venting requirements.

residentEvil · Nov 24, 2006, 09:38 AM

call someone else.

ask this old house did 1/2 an eposide on this and that 'some' contractors pass on the job because of the venting work. call someone else. most plumbers don't want to deal with the penetration to the outside to install the new venting stacks.

(in almost 95% of the time, you can't reuse the one for the current normal gas/electrc water heater). there are special requirements; but it can be done.