Hot water on demand?

[Guest Derek L]

I suppose this is in the right area since it’s relating to Science and Tech etc…………My question, does anyone have Hot water on demand in your home? What’s your experience/opinion? My home currently is heated through hot water and our potable hot water through a 70 gallon hot water tank, but our HWT is just creeping up on it’s warranty and we’re currently debating putting in either a HW on demand system or upgrading our boiler and having an indirect system installed (At great expense).

[Wild Bill]

I suppose this is in the right area since it’s relating to Science and Tech etc…………My question, does anyone have Hot water on demand in your home? What’s your experience/opinion? My home currently is heated through hot water and our potable hot water through a 70 gallon hot water tank, but our HWT is just creeping up on it’s warranty and we’re currently debating putting in either a HW on demand system or upgrading our boiler and having an indirect system installed (At great expense).

I've wondered this too, Derek. I've heard mixed reports. Most negatives have to do with a short time lag for hot water to appear. That seemed to me to be a non sequitur - ordinary water heaters have always done the same!

What is true is that the technology has no proven history. Does one of these on-demand systems typically last as long as a traditional one?

That's a question I would like answered.

[eyeball]

They're okay where the demand is really small like on a boat but I wouldn't put one in my home. Hot usually just means warm on any that I've used. I had an electric one in my shop and it basically would have sucked for anything like a real shower or big load of laundry.

[Guest Derek L]

I've wondered this too, Derek. I've heard mixed reports. Most negatives have to do with a short time lag for hot water to appear. That seemed to me to be a non sequitur - ordinary water heaters have always done the same!

What is true is that the technology has no proven history. Does one of these on-demand systems typically last as long as a traditional one?

That's a question I would like answered.

I do have some direct knowledge in the field, My uncle (will be 70 this year) owns a small plumbing company in Greater Victoria (Guess what my part time job was in school)but doesn't have alot of experience with the Gas on demand, coupled with a piece of paper hanging on the wall with Engineering and Management written on it……..But from looking into it, it’s really hard to get the straight goods on the On demand system in terms of lifespan etc……

On paper I can understand that the indirect system feeding off a boiler is the most proven and tested (That’s how most large buildings work after all) but it’s a really expensive initial outlay. From talking with my uncle and the little I understand about Gas/BTUs my current boiler is undersized to hook-up the indirect system…..So that means replacing my ten year old boiler, controls and the cost of the storage tank (And possibly upgrading my venting)

Contrast this with having a HWoD system, which will require a combustion air inlet and vent (And ripping apart a good chunk of ceiling in the basement), but will only cost about a third of the price to install…….Like you’ve said, I don’t know how mature the technology is yet or how long it will last, so if they’re lemons I’d rather spend the big bucks on the indirect system and not have to think about replacing it until I’m old and senile………

Personally, I’m leaning towards the indirect system (for the above stated reasons) well my wife and her coven of friends all rave about having unlimited hot water for their Filipino nannies to cook dinner with……So I guess Bill, we’re both stuck on the same question LOL

[Guest Derek L]

They're okay where the demand is really small like on a boat but I wouldn't put one in my home. Hot usually just means warm on any that I've used. I had an electric one in my shop and it basically would have sucked for anything like a real shower or big load of laundry.

Yeah, I’ve read that the electric ones, as well as the instant hot ones you put under your sink, have a very lousy return, over here on the mainland though we all pretty much have gas so they‘re a little more efficient (But Gas is a lot more expensive than Hydro)……..Would the one on your boat run off propane?

[eyeball]

Yeah, I’ve read that the electric ones, as well as the instant hot ones you put under your sink, have a very lousy return, over here on the mainland though we all pretty much have gas so they‘re a little more efficient (But Gas is a lot more expensive than Hydro)……..Would the one on your boat run off propane?

No it's an old fashioned kettle on a diesel fuelled stove. I've worked on a few vessels that had smaller electric varieties. Most larger vessels I've been on have conventional hot water heaters powered by electric gensets. I've no experience with the gas powered ones probably because propane is usually a pretty dicey thing to use on a boat due to a greater risk of an explosion on a vessel.

[Guest Derek L]

No it's an old fashioned kettle on a diesel fuelled stove. I've worked on a few vessels that had smaller electric varieties. Most larger vessels I've been on have conventional hot water heaters powered by electric gensets. I've no experience with the gas powered ones probably because propane is usually a pretty dicey thing to use on a boat due to a greater risk of an explosion on a vessel.

Yeah, I guess that would make sense in regards to propane……..Fire doesn’t care if you’re on a fishing boat or a 5k ton Destroyer…….

[TimG]

What’s your experience/opinion?

Used gas ones in Japan. Works fine for washing dishes by hand and heating a bathtub (by cycling the water through the machine again and again). Sucks for showers or any other appliance that needs a flow larger than its capacity. You may find modern ones with large enough capacity to allow for a decent shower. Edited January 30, 2012 by TimG

[eyeball]

Yeah, I guess that would make sense in regards to propane……..Fire doesn’t care if you’re on a fishing boat or a 5k ton Destroyer…….

Propane on a boat really gives me the willies. I've seen what happens to a boat when gasoline fumes blow up. It can peel a deck off like a sardine can. I'll settle for the stove top bird bath or just jump over the side from time to time thanks.

[cybercoma]

I would take a look into the gas ones you can get here. Electric is useless and the whole-house systems are nothing at all like the toys you hook up to a kitchen sink.

I'm not entirely certain, but I would imagine that they would just as long if not longer than a tank. They come with 20 or 25 year warranties on them like the better tanks do. Also, if you take a look at how they're made, it's just a copper pipe that wraps several times around and is attached to a plate that is heated by your propane flame. A tank has standing water in it all the time, so that's why they will not only corrode (although new ones should last decades with the liners in them now), but the elements in them will accumulate residue and not heat as efficiently over time.

Anyway, I don't have one myself, but my brother-in-law, who is a commercial plumber, installed one in his home when he built it. When we stayed at their place over the summer we couldn't even tell the difference when we took showers. I'm thinking when our tank goes, that's the way we're going to go. He's using gas though. From my extremely limited knowledge about them, the electric ones don't keep up if you're running a shower and turn on just about anything else.

[Guest Derek L]

Used gas ones in Japan. Works fine for washing dishes by hand and heating a bathtub (by cycling the water through the machine again and again). Sucks for showers or any other appliance that needs a flow larger than its capacity. You may find modern ones with large enough capacity to allow for a decent shower.

Yeah, from what I’ve read, the ones in Japan/Korea/Germany are very popular and reliable, I just wonder if the same level of quality is here yet.

[Guest Derek L]

Propane on a boat really gives me the willies. I've seen what happens to a boat when gasoline fumes blow up. It can peel a deck off like a sardine can. I'll settle for the stove top bird bath or just jump over the side from time to time thanks.

Yeah, I assume it would have just as devastating affects as JP-5 vapour, but with a much lower flash point.

Edited January 30, 2012 by Derek L

[Guest Derek L]

I would take a look into the gas ones you can get here. Electric is useless and the whole-house systems are nothing at all like the toys you hook up to a kitchen sink.

I'm not entirely certain, but I would imagine that they would just as long if not longer than a tank. They come with 20 or 25 year warranties on them like the better tanks do. Also, if you take a look at how they're made, it's just a copper pipe that wraps several times around and is attached to a plate that is heated by your propane flame. A tank has standing water in it all the time, so that's why they will not only corrode (although new ones should last decades with the liners in them now), but the elements in them will accumulate residue and not heat as efficiently over time.

Anyway, I don't have one myself, but my brother-in-law, who is a commercial plumber, installed one in his home when he built it. When we stayed at their place over the summer we couldn't even tell the difference when we took showers. I'm thinking when our tank goes, that's the way we're going to go. He's using gas though. From my extremely limited knowledge about them, the electric ones don't keep up if you're running a shower and turn on just about anything else.

25 year warranty? What brand tank is that? I’ve got a Bradford White, which came with an 8 year and they are suppose to be the best…..I replaced, not even two months into my home, a three year old John Wood that had a faulty gas valve………If you know of a regular natural gas tank (65-70 gallon ish) with a 25 year warranty, let me know……LOL…….I’ll get one and put it in myself and pull a gas permit under my uncle’s licence…….That would save a fortune!!!!!

[cybercoma]

Sorry, it's 12 years.

http://www.cpotanklesswaterheaters.com/bosch-tankless-warranty/bosch-tankless-warranty,default,pg.html

[cybercoma]

Oh and the life expectancy is 20 years:

hxxp://www.cpotanklesswaterheaters.com/aquastar-2700es-ng-natural-gas-tankless-water-heater/aqrn2700es-ng,default,pd.html?start=4&cgid=bosch-tankless-aquastar

commas in the link. copy and change hxxp to http

Edited January 30, 2012 by cybercoma

[Guest Derek L]

Sorry, it's 12 years.

http://www.cpotanklesswaterheaters.com/bosch-tankless-warranty/bosch-tankless-warranty,default,pg.html

That’s for a tank less? Yuk……..I’ve had other bosch appliances and wasn’t impressed…

Edited January 30, 2012 by Derek L

[cybercoma]

Yeah. I thought that's what we were talking about here, no?

[sharkman]

A friend of mine installed an on demand unit in his house and is happy with it, although the first one was replaced under warranty in the first year. If they have a 20 year life, that's much longer than a traditional tank and much cheaper to run too.

[Guest Derek L]

Yeah. I thought that's what we were talking about here, no?

I was responding to this part:

They come with 20 or 25 year warranties on them like the better tanks do

[Guest Derek L]

A friend of mine installed an on demand unit in his house and is happy with it, although the first one was replaced under warranty in the first year. If they have a 20 year life, that's much longer than a traditional tank and much cheaper to run too.

You see that’s a couple of negative things that I’ve heard from a few friends that got them when they first came out…….One friend went through two during the first three years, and in each case the plumbing company had to order parts to try and fix them prior to replacing the entire unit…..Perhaps this was more an issue with the plumber than the unit, likewise, now perhaps that they are more common, parts are easier to get a hold of?

[sharkman]

I should ask my friend, it seems to me that his brand/model had some issues. This was about 2 years ago now.

[August1991]

Interesting thread.

I have lived abroad (in Europe and Asia) and I have even dealt with the problem of heating water in Canada (at cottages).

IMV, if natural gas is cheap, then an instant hot water heater (HWOD) makes sense. If electricity is cheap, then a tank of hot water makes sense. In addition, if you live in a climate where home heating is an issue, then the tank of hot water also heats your home.

In Canada, given our hydro and climate, I think it makes more sense to have a tank of hot water in your home. Then again, if you live off the grid, or if propane drops further in price, or if you travel south in the winter, it may make sense to switch to a gas on-demand water heater.

[bTW, I have used small electrical water heaters in Eastern Europe. These are typically for electrical outages or when the central hot water is turned off for maintenance. Avoid.]

Incidentally, dishwashers and clothes washers sold outside North America typically have internal water heaters and only require one (cold) water intake. The cleaning process takes longer since the water must first be heated.

Anyway, I don't have one myself, but my brother-in-law, who is a commercial plumber, installed one in his home when he built it. When we stayed at their place over the summer we couldn't even tell the difference when we took showers. I'm thinking when our tank goes, that's the way we're going to go. He's using gas though. From my extremely limited knowledge about them, the electric ones don't keep up if you're running a shower and turn on just about anything else.

Gas is the key point.

Used gas ones in Japan. Works fine for washing dishes by hand and heating a bathtub (by cycling the water through the machine again and again). Sucks for showers or any other appliance that needs a flow larger than its capacity. You may find modern ones with large enough capacity to allow for a decent shower.

I disagree. A good gas water heater will create enough hot water for most needs.

On paper I can understand that the indirect system feeding off a boiler is the most proven and tested (That’s how most large buildings work after all) but it’s a really expensive initial outlay. From talking with my uncle and the little I understand about Gas/BTUs my current boiler is undersized to hook-up the indirect system…..So that means replacing my ten year old boiler, controls and the cost of the storage tank (And possibly upgrading my venting)

Contrast this with having a HWoD system, which will require a combustion air inlet and vent (And ripping apart a good chunk of ceiling in the basement), but will only cost about a third of the price to install…….Like you’ve said, I don’t know how mature the technology is yet or how long it will last, so if they’re lemons I’d rather spen

d the big bucks on the indirect system and not have to think about replacing it until I’m old and senile………

Good points.

Last point: In Sri Lanka, I had a metal container on my roof. I took "warm" showers in the morning and "hot" showers in the evening.

Edited January 31, 2012 by August1991

[bush_cheney2004]

Went through this last year...wanted to (not needed to) replace a 40 gallon gas water heater after 15 years of reliable, trouble free service. I always replace the sacrificial anode rods mid warranty period and run the thermostat at 50C for a long tank life.

What a fiasco the tankless would have been...from initial cost ($1,000) to installation ($1500)...to higher energy cost at peak demand. No thanks....I was able to remove and install a brand new tank heater (12 year warranty) for $425...simple DIY with basic plumbing skills.

Tankless = thankless

http://www.waterheaterrescue.com/pages/WHRpages/English/Longevity/tankless.html

[Guest Derek L]

Interesting thread.

I have lived abroad (in Europe and Asia) and I have even dealt with the problem of heating water in Canada (at cottages).

IMV, if natural gas is cheap, then an instant hot water heater (HWOD) makes sense. If electricity is cheap, then a tank of hot water makes sense. In addition, if you live in a climate where home heating is an issue, then the tank of hot water also heats your home.

In Canada, given our hydro and climate, I think it makes more sense to have a tank of hot water in your home. Then again, if you live off the grid, or if propane drops further in price, or if you travel south in the winter, it may make sense to switch to a gas on-demand water heater.

[bTW, I have used small electrical water heaters in Eastern Europe. These are typically for electrical outages or when the central hot water is turned off for maintenance. Avoid.]

Incidentally, dishwashers and clothes washers sold outside North America typically have internal water heaters and only require one (cold) water intake. The cleaning process takes longer since the water must first be heated.

Gas is the key point.

I disagree. A good gas water heater will create enough hot water for most needs.

Good points.

Last point: In Sri Lanka, I had a metal container on my roof. I took "warm" showers in the morning and "hot" showers in the evening.

Good points August!! Thanks!! My brother in-law (Wife’s Brother) lives in Holland and loves the bloody (German) tank less set-up and has contributed to clouding my wife’s opinion on how backwards us North American’s are lol……..

Your point about the dishwasher is interesting…….Of course, my wife children would probably complain about having to warm all that water up prior.

[Guest Derek L]

Went through this last year...wanted to (not needed to) replace a 40 gallon gas water heater after 15 years of reliable, trouble free service. I always replace the sacrificial anode rods mid warranty period and run the thermostat at 50C for a long tank life.

What a fiasco the tankless would have been...from initial cost ($1,000) to installation ($1500)...to higher energy cost at peak demand. No thanks....I was able to remove and install a brand new tank heater (12 year warranty) for $425...simple DIY with basic plumbing skills.

Tankless = thankless

http://www.waterheaterrescue.com/pages/WHRpages/English/Longevity/tankless.html

I like the point about being able to “do it” yourself……..I’ve changed the tanks in our old home and rental property (Both electric), amongst “helping” my uncle as a kid with numerous ones……..I’ve found that when “doing it yourself”, it’s rather handy to have a lummox of a teenage son around.

As for touching our boiler or any other gas appliance, though I’m perfectly comfortable doing so, the last time I was about to change a thermocouple on our HWT, my wife threatened to take the kids and stay in a hotel for the night…..Suffice to say, we call a licensed pro when it comes to natural gas.