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Info on tankless water heaters

2K views 9 replies 8 participants last post by  Ghostmaker 
#1 ·
I'm looking for some information about tank less water heaters.

1. I have heard some models can be a real nightmare to install (Rheem was one I heard this about on many sites). My water heater now is in the bedroom closet with no exterior wall, it vents through the roof. So if I am using concentric venting I have heard for some source that this can be a pain to install. Is this the case?

2. I am in a modular with 2 bathrooms and I have lots of the old grey plastic tubing throughout the house ( I forget what it's called). As needed and where I can access it i have replaced some of this with PEX. I understand that depending on what unit I go with I need to us copper or other metal piping or hoses for the first 6"-36" inches in and out of the heater. However I have also heard that the there should be NO plastic pipe down stream of the tankless heater. Is this the case? it just seems odd since I have hot water in those pipes now.

3. If a tankless will work for me are there any recommendations as to a model that's not going to cost me an arm and a leg to buy and put in?

Thanks in advance.
 
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#2 ·
Just my own opion, it's just not worth it.
The gas line size would have to be increased, the vent pipe needed is very expencive. Lots more maintance, by the time you get a pay back or the fuel savings it will need to be replaced.
I've plumbed many a house with pex with tankless heaters and never had a call back.
And your right all that old Quest tubing needs to go.

I can not imagine any type of gas device being to code installed in a bedroom closit.
 
#3 ·
Vertical venting is possible- just make sure whatever unit you get is rated for a bedroom.
Qest pipe needs to go- pex should not be an issue. It will handle the temp range.
Hang around and some of the guys that have tankless will chime in or you could search the forum. This has been discussed here several times
 
#4 ·
There seem to be two general opinions of tankless heaters: 1. Best thing ever invented. 2. Worst thing ever invented.

That said, we have a gas tankless unit (Rheem Eco-Sense) in our home. We built the house ourselves, so I installed it. I paid the gas company to run the line for it when they were onsite doing the furnace. The installation was not that difficult. I mounted it on an outside wall and vented it horizontally through the wall. There was no wiring to do; the unit plugs into a regular 120V outlet. I did discuss the installation with the inspector in advance because there are restrictions on how far the vent has to be from doors, windows, etc.

I doubt we will ever recover the cost difference between the tankless and a "regular" water heater, but I don't care. We are both in our 60s and this is our last home. It's a log house we built almost entirely by ourselves, so we never plan to move. Besides just being interested in tankless heaters and wanting to try one, we chose one because they are much smaller and easier to hide.

We've been in the house about three years now, and have had zero issues with the heater. Other than cleaning the water inlet filter once in a while, there's been no maintenance at all.

A caution about tankless heaters: if you have hard water, they do not last very long, particularly the electric ones. We have a water treatment system so that's not an issue for us. I have no specific personal knowlege, but have heard that some companies will not even install a tankless if you have hard water.
 
#7 ·
There seem to be two general opinions of tankless heaters: 1. Best thing ever invented. 2. Worst thing ever invented.
Pretty accurate statement.

I did a lot of research into them before doing my 2-story addition...what I basically determined...

If you already have gas....the payback is a lot longer....if it's electric...then the payback is shorter...assuming you have the power.

If you have gas....the payback is only realistic if you are not using it all day. If your the 'shower in the morning...then nothing until evening'...then it can be worthwhile. But if your using hot water all day...a tank heater is a better deal.

The other condition....location.....if your tank is a long distance from the load....and the tankless can be at the POU...then it 'might' be viable...

I paid like $400 for my 50 gal 12 year tank....2 adults, 3 kids....we have yet to run out of hot water.
 
#5 ·
Thanks all, good info so far. I do have hard water--very hard and in fact was going to be putting in a new softener as part of this install. So given that would a tank less still be a bad choice? To be frank I'd love to put another tank heater in so it is just a swap out but the wife heard about tank less units and is just set on one---I'm sure some here can relate to that.:laughing:
In any case any good ammo I can use to convince her other wise would be a help--so far a good start, thanks.

I would love to get rid of all that old nasty grey quest piping but that would require tearing up flooring all through the house and does not look like a fun or easy project no matter how I cut it.:eek:

Our modular is odd, that's where the heater is and has always been, in the bed room closet. But the thing was designed that way and others in the area are like that so someone approved it at some point. :laughing:
 
#6 ·
I just posted a rebuttal on PB piping on another post. I can tell you that there is nothing wrong with the piping IF you have well water. If you have chlorinated water its a different story. IF you have well water, the problems you will have will be in the connections. You will have trouble with aluminum crimp rings. Shark bites work very well with PB.

Your problem will come when and if you go to sell your home. If they see PB they will yell bloody murder.

The big wonder product now is PEX. Looks like a winner so far, but Connecting two materials that expand and contract at very different rates with thermal change with a crimp ring gives me the willies. We shall see.

Till we do, I am sticking with soldered copper, and glued CPVC
 
#8 ·
@ mrnightime. If you are looking for artillery against getting a tankless, I can provide 2 points of interest.

1. PLease have it professionally installed in very direct accordance to maufacturers reccomondations.

2. Most manufacturers reccommend tankless heaters get flushed once a year with a deliming or vinegar solution and that will add to the investment.
 
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