Tankless on demand hot water, are they any good?

[88CRX]

Was a thread on here a couple years ago, and it was mostly negative comments. Have they improved?

New build spec includes on demand so i don't really care what the capital costs are. But what about maintenance and how well do they work?

[revelations]

Apparently combined with the maintenance headaches (unless you prefilter and soften water) for our water and the climatic issues (water comes out of the ground very cold) its not really recommended here in Calgary.

[Kavy]

Was not a fan of ours and ended up getting a traditional water tank after about a year and a half.

[thinmyster]

Originally posted by Kavy
Was not a fan of ours and ended up getting a traditional water tank after about a year and a half.

We bought our house in 2013. It had a tankless unit from ~2008 so pretty new technology at the time. But yeah, we had a lot of problems and switched to a tank last year. I gave all my maintenance stuff to my neighbour who is happy with his switch to tankless

[BokCh0y]

We built a new house earlier this year, came with tankless but I changed it to a traditional tank. My buddy had one in his house and it was a lot of trouble in terms of maintenance and such, so his recommendation to me was to go for a traditional system.

[Tik-Tok]

I think a more cost-friendly solution for our climate would be a small point-of-use tankless heater under the kitchen sink. That way you have instant hot water there and don't have to keep the water running excessive and draining the HW tank.

One of those things on my "to buy when have spare money" items.

[digi355]

I've had one since 2010. No issues at all. It's nice always having hot water regardless of what you're doing in the house but with that being said when I had a hot water tank, I think I ran out of hot water 2 or 3 times...

Mine came with the house. If it cost a lot more, I don't think I'd buy one to replace it, if it was about the same, I'd totally do it again.

[ganesh]

Originally posted by Tik-Tok
I think a more cost-friendly solution for our climate would be a small point-of-use tankless heater under the kitchen sink. That way you have instant hot water there and don't have to keep the water running excessive and draining the HW tank.

One of those things on my "to buy when have spare money" items.

You don't need a tankless heater to do that. If you want instant hot water all you need is a small pump which is attach to the hot water tank and it will re-circle the water. In our current (Built in 2014 by Morrison) it came with the pump and it does the magic for us.

As for what OP was asking, when I replaced the hot water tank in my previous house I looked at the tankless hot water tank and I was told to stay away from it for the reasons other people have listed here. Also I was told it works well in US climate and it doesn't cut it here in our cold weather.

[G]

Originally posted by ganesh


You don't need a tankless heater to do that. If you want instant hot water all you need is a small pump which is attach to the hot water tank and it will re-circle the water. In our current (Built in 2014 by Morrison) it came with the pump and it does the magic for us.

As for what OP was asking, when I replaced the hot water tank in my previous house I looked at the tankless hot water tank and I was told to stay away from it for the reasons other people have listed here. Also I was told it works well in US climate and it doesn't cut it here in our cold weather.

My recirculation pump actually has a timer on it so it recircs only when we use water after a long idle time like first thing in the morning or coming home from work. If you have the pump on all the time you're use a lot of gas to keep the water hot all the time. If yours don't have a timer you should plug it into those timers that can turn on/off Christmas lights.

[ganesh]

Originally posted by G


My recirculation pump actually has a timer on it so it recircs only when we use water after a long idle time like first thing in the morning or coming home from work. If you have the pump on all the time you're use a lot of gas to keep the water hot all the time. If yours don't have a timer you should plug it into those timers that can turn on/off Christmas lights.

Mine has a timer and Temp control in the pump as well.
My schedule is similar to what you have done.

[jwslam]

Originally posted by ganesh
You don't need a tankless heater to do that. If you want instant hot water all you need is a small pump which is attach to the hot water tank and it will re-circle the water. In our current (Built in 2014 by Morrison) it came with the pump and it does the magic for us.
That sounds like a stupid use of energy unless you're using it as heat too

edit: just saw the timer posts.

[ExtraSlow]

Would love a tankless one, but cost and maintenance are issues. Can confirm my jetted tub in the ensuite will drain an entire 60 Gal tank in one fill, and leave no water for doing dishes . . .

Recirc pump is a good setup, I don't have that.

I think anyone looking at high capacity tanks should consider running dual 40Gal tanks instead of one large one, cost is similar and if/when one needs replacing or maintenence, you have the other to rely on. A buddy of mine built his house that way and it seems smart. Of course, it's much easier to do in a new build than as a retro-fit.

[redevil]

I have had one since 2012 (Rinnai brand) when we built a new home. Also have a water softener as well to help with the hard water. It is connected to a water recirc pump on a timer during the day. Recirc pump doesn't trigger my water heater flame, all it does is moves the water through the unit and over the pilot light that is constantly on so using the current heat from the pilot light. Only when I turn the hot water tap on does it fire up.

I've tried it without the recirc pump and timer but found it took too long in the morning or during the day to get hot water at the taps. By using both recirc/timer it avoids wasting water by running it till it gets hot.

So far I love it, never run out of hot water for when my kids get older...

[JfuckinC]

What about if I keep my old hot water tank, turn it on as low as possible, as a pre-heater then put a tankless water heater after it :dunno: haha I wonder which way that would go for efficiency

[killramos]

My old boss had one, what I remember about it was he had to miss a day of work every 4-5 months like clockwork because the system was acting up and he needed to be home for the repairman. The cost of the bills were insane too...

Likes like a giant PIA for a very minor convenience. Better off just way overdoing tank capacity, or turning the temp way up.

[redevil]

Originally posted by JfuckinC
What about if I keep my old hot water tank, turn it on as low as possible, as a pre-heater then put a tankless water heater after it :dunno: haha I wonder which way that would go for efficiency

I think there is a setup like this but as a storage tank for the hot water. Not sure how efficient it will be or if you can use your old tank. :dunno:

[schocker]

Had been looking into these as I currently have an electric water heater (thanks shane) but it still sounds like there are some issues. I do think some now come with their own recycle pumps and they have eliminated the cold water gaps with an idle time which alleviates some of the older issues. Would be nice to use the current rebate, but it only lists moving from a nat gas tank....

[88CRX]

Interesting feedback guys.... lots to think about.


Originally posted by schocker
Had been looking into these as I currently have an electric water heater (thanks shane) but it still sounds like there are some issues. I do think some now come with their own recycle pumps and they have eliminated the cold water gaps with an idle time which alleviates some of the older issues. Would be nice to use the current rebate, but it only lists moving from a nat gas tank....

So you'd want gas tank over electrical tank?

[G]

Don't get electric tanks. My brother has one and his bills are astronimical compared to my house all things taken into consideration, number of users, size of house....

[SOAB]

i have one at home. can't remember what brand but maintenance isn't crazy on it. just hook up a recirc pump in a bucket with vinegar twice a year. let it run for an hour and you're done.

like it but wouldn't pay to replace a conventional tank for a tankless system.

[BokCh0y]

Originally posted by G
Don't get electric tanks. My brother has one and his bills are astronimical compared to my house all things taken into consideration, number of users, size of house....

Yeah i heard that too. My buddy went from electric back to gas.

[schocker]

Originally posted by 88CRX

So you'd want gas tank over electrical tank?
Absolutely, the amount of power it uses it very high. I have a recycle pump too so that doesn't help but instant hot water is very nice.

[Swank]

Can you add a recirc pump to any set up, or does the plumbing and/or tank need to be designed for that? I know very little about plumbing, so I'm confused how it would circulate.

[jwslam]

Originally posted by Swank
Can you add a recirc pump to any set up, or does the plumbing and/or tank need to be designed for that? I know very little about plumbing, so I'm confused how it would circulate.
As it stands, your piping is probably one way from tank to faucets, etc. Makes sense for recirc there needs to be a line for it to flow back to the tank and pumped in circles.

[revelations]

Originally posted by redevil


I think there is a setup like this but as a storage tank for the hot water. Not sure how efficient it will be or if you can use your old tank. :dunno:

I've heard this as well. Add extra insulation to the unit and it will hold water warm for a while, for sure.

[Swank]

Originally posted by jwslam

As it stands, your piping is probably one way from tank to faucets, etc. Makes sense for recirc there needs to be a line for it to flow back to the tank and pumped in circles. That's what I was thinking too, drat.

[schocker]

Originally posted by Swank
Can you add a recirc pump to any set up, or does the plumbing and/or tank need to be designed for that? I know very little about plumbing, so I'm confused how it would circulate.
I have been on a this old house binge....

KdA_gfau1s4

Looks like you can and it can push against the cold water line until the temp trips the pump to turn off.

[phreezee]

^That's old. They are installed on the tank with a bypass valve under the sink of the farthest line.

http://www.wattscanada.ca/pages/whatsnew/IHWRS.asp

I installed mine pretty easily with a utility knife, pex crimpers, and a wrench.

[schocker]

Ah, that one makes more sense and is much more clean.

[Swank]

Sweet. This is very tempting now, hot water takes ages to reach the washrooms :cry:

[suntan]

Originally posted by phreezee
^That's old. They are installed on the tank with a bypass valve under the sink of the farthest line.

http://www.wattscanada.ca/pages/whatsnew/IHWRS.asp

I installed mine pretty easily with a utility knife, pex crimpers, and a wrench. Did it impact your electricity bill? I've read that some people have complained that they use a lot of electricity, but that might just be user error.

[jwslam]

Originally posted by phreezee
^That's old. They are installed on the tank with a bypass valve under the sink of the farthest line.

http://www.wattscanada.ca/pages/whatsnew/IHWRS.asp

I installed mine pretty easily with a utility knife, pex crimpers, and a wrench.
So then my cold water might not come out cold...

[Tik-Tok]

Originally posted by jwslam

So then my cold water might not come out cold...

That's what I was thinking too. You'll use just as much water getting cold water out of the tap, and use extra electricity instead of extra gas.

So no savings probably (results may vary), but just the convenience of warm/hot water instantly.

[Swank]

What do you need cold for? Only psychopaths take cold showers, and everyone on beyond drinks Veen or Kona Nigari from their mini water fridge in each room....well maybe some Fiji in this economy :rofl:

[phreezee]

Originally posted by jwslam

So then my cold water might not come out cold...

The by-pass valve is temperature activated to only re-circ to cold side when the hot side temp drops below threshold.

The cold water is still cold, just not ice cold at first. If you run it 10 seconds it is back to normal.

[jwslam]

Originally posted by phreezee
The by-pass valve is temperature activated to only re-circ to cold side when the hot side temp drops below threshold.

The cold water is still cold, just not ice cold at first. If you run it 10 seconds it is back to normal.
So then instead of having to run water to get hot now, I'm bothered by having to run water to get cold :rofl: :rofl:

[phreezee]

It's moot for me because the only time I'd want really cold water is if I was going to drink it, but I have soft water coming to the bathrooms.

Kitchen line is separate and isn't affected.