Tankless water heaters

[KD0AXS]

So, it's time to replace our water heater. Our current water heater is an AO Smith 50 gallon propane unit with a power vent. It's about 12 years old.

We're strongly considering a tankless unit, but I don't really know what's a good unit and what isn't so I'd definitely appreciate some input from anyone who does.

Here are a few I've found that seem to be a good match for our needs.

First, this Richmond unit from Menards. They have an 11% rebate right now, so that would certainly be nice. They also have this unit in stock. I could go buy this one right now and install it tomorrow. No one else locally has anything in stock, I'd have to order it.

http://www.menards.com/main/plumbin...v-9-5-gpm/p-2422015-c-8690.htm?freeFormRowId=

Home Depot has this Rheem unit which seems to get decent reviews on their website.

(broken link removed)

This AO Smith unit is the one I'm leaning towards right now. It's on eBay, but the seller is a reputable plumbing supply dealer.

(broken link removed to http://m.ebay.com/itm/AO-Smith-ATI-540H-P-Condensing-Tankless-Water-Heater-Propane-/310781347562)

I've never heard of Navien before, but this looks to be another unit that would be a good match for our needs.

https://www.acwholesalers.com/Navie...c?catId=cat20496&mainCat=&subCat=&trail=49992

Any other recommendations would definitely be welcome.

Or, if anyone has a compelling reason why we should stick with a traditional tank unit, I'd definitely welcome those comments too.

Thanks!

 

[DougA]

The best advice I heard was from a plumber who sold tankless units. He put one in his own house but also installed a small tank with heater on the house side of the plumbing. I've owned tankless and it does take a few moments of running the water before you get hot water. That bothers most people, so a small tank stores enough water to make up that difference. Newer washers and dishwashers use much less hot water and you may find that by the time hot water reaches them, they stop drawing water. Even with a tank, we are getting that with our new dishwasher due to the 20' run between the tank and the dishwasher.
Also, don't assume your existing tank needs replacing without checking it carefully. I've got a 40 gal. electric (no gas or propane available) that is 33 yrs. old and no signs of problems at all. I do have a moisture alarm at the base, just in case.

 

[KD0AXS]

Thanks for the info. I'm aware of having to wait for hot water with a tankless heater. We're used to waiting already, so that's no big deal. Seems our house was built to make the plumbing runs as long as possible. Bathrooms are all at the north end of the house, and the kitchen sink, dishwasher, and laundry are all along the south wall of the house. Usually I make sure I have hot water at the sink before starting the dishwasher.

Our current water heater definitely needs to be replaced. It's so rusty that pieces of rust are falling on the burner. These pieces of rust interfere with the flame, and that causes it to shut down.

 

[Warm_in_NH]

Rinnai is a very popular brand around here. As a contractor I see a lot of my customers putting them in during remodels.
Can't offer up much more than that but for some reason they're definitely the most popular by far around here. May be worth looking into...

 

[gzecc]

I installed a Bosch many years ago with gas. It worked well.

 

[Dr.Faustus]

I always wanted to try one of those tankless style heaters. unfortunately after a bit of research I decided it wouldn't be a good idea. I have well water and it has an abundance of iron in it. so much that even our extra high capacity softener cant get it below a moderate level. after our softener, we use an RO unit for our drinking water which then reduces it to 0.

Water like this clogs up these tankless heaters in a hurry and it would be a constant battle. With the tank kind, all I have to do is once in a while pull and clean the elements, flush out the bottom of the tank and good to go again. make sure your water isn't like this before you try tankless.

 

[mithesaint]

Do you need limitless hot water? If not, look into a heat pump water heater. I have the GE Geospring, and it's been great. When I was able to track the electric bill, the increase was minimal to non-existant, even when taking into account I went from propane to electric. I have a very humid basement, and it helps to not have to run the dehumidifier 24/7 because of the geospring.

I did have to have a electric line ran to the heater, so that slows down the payback, but it should still pay for itself in 2-3 years, and then it's free money after that.

 

[KD0AXS]

We don't necessarily need unlimited hot water, but we do have a 2 person Jacuzzi in the master bath which is too much for our current 50 gallon water heater. If we stick with a tank type unit, we'd have to get a bigger one. A 75 gallon power vent water heater runs around $1200, about the same as larger tankless units I've been looking at. A 50 gallon power vent unit is around $1000.

I'll do some more looking into the Geospring units. Looks like Lowes has an 80 gallon Geospring for $1600. I would also have to run a 240V circuit for it, but a tankless unit would require some minor re-routing of plumbing and probably a larger gas line as well.


I did find this Rinnai tankless unit. If I go tankless, this would probably be the one I'd go with. In the research I've been doing, Rinnai does seem to be the most recommended brand.

https://libertywholesalesupply.com/...propane-condensing-tankless-water-heater.html

 

[HitzerHillbilly]

Our geothermal heating + A/C unit keep our hot water heater at 120° anytime it is running. Now in the winter it doesn't run much so it's run on electric then.

 

[Highbeam]

I have well water and it has an abundance of iron in it. so much that even our extra high capacity softener cant get it below a moderate level. after our softener, we use an RO unit for our drinking water which then reduces it to 0.

Why would you use a softener to remove iron? They make actual iron removal systems that are very effective. I have one. I do not have a hard water problem so no need to soften the water. I realize that softeners can also remove a small amount of iron since the softener sees iron as a hardness ion but there are certainly better ways like with manganese oxide. Mangox removes iron, manganese, and sulfur without wasting money on salt.

 

[velvetfoot]

I add a little iron out to the softener brine tank.

 

[KD0AXS]

Well, it looks like the tankless idea is out. Turns out that I'd have to replace the supply lines all the way from the tank in order to support the BTUs.

The Geospring is now looking like the best option I think. The wife can get a discount from Sears through her work, and our electric company has a $200 rebate so we should be able to get one for a pretty good price. I'll have to run a 220V circuit for it, but that's no big deal.

Also considering a direct replacement of what we have now, but I think we can get the Geospring for about the same price as a power vent propane water heater, plus it's probably cheaper to run and has a 10 year warranty vs 6.

 

[RustyShackleford]

Tankless water heaters are a scam. The idea is that you save the waste from keeping a tank of water hot all the time. But do the computation of how much energy is wasted - quite simple, just the tank's surface area, times the temperature differential (between the hot water and the outside air), divided by the R-value of the tank insulation (16 for a good modern high-efficiency unit). You get a pretty small number. This waste is dwarfed by the losses from the hot water that is left in the pipes after you turn on the hot-water faucet, use it, and then turn it off. Perhaps if you have a tankless unit in every bathroom and in the kitchen, you'd reduce those losses. But that would cost so much money that it'd be better spent on a photovoltaic solar installation. Also, tankless units are much more failure prone, and parts are expensive and hard to get (the guy who helps me with this stuff says that some companies won't even sell him parts, because he hasn't been to their factory school).

 

[DougA]

Why would you use a softener to remove iron?

We use a softener to reduce our iron and sulfur content which is moderate but not high. We looked at other options and the softener removes enough to eliminate most of the problems. We also use Iron Out a few times a month and it's kept things working for 30 yrs. of use.

 

[fbelec]

i wired a 50 gallon geospring and it had a small jacuzzi in it's run the geospring did not give enough hot water to fill the tub. if you are going to use that tub you will need a tankless style or a 120 gallon tank style. because of the heater not giving enough hot water the geospring was raise up to 140 degrees and still didn't work. the home owner had me wire in a separate 1500 watt in line at the tub heater and that raised the temp 5 degrees after twenty minutes of run time.

 

[DickRussell]

Here is a blog from GBA that discusses the economics of tankless water heaters.
http://www.greenbuildingadvisor.com/blogs/dept/musings/are-tankless-water-heaters-waste-money

 

[drz1050]

Has GE fixed the Geospring issues? Amazon reviews are quite horrid:

http://www.amazon.com/gp/aw/reviews/B006UA7930

 

[begreen]

Allegedly yes, but I'm waiting for a few years.

 

[KD0AXS]

I guess we'll find out. I installed the Geospring last weekend. So far it's working great, although we haven't used the Jacuzzi yet.

 

[fbelec]

good luck filling the jac. it is a amazing thing watching that work. the standard electric water heater take about 18 amps. i put my amprobe on the last 2 i wired and it only pulled 7 to 7.5 amps. nice.

 

[semipro]

Has GE fixed the Geospring issues? Amazon reviews are quite horrid:

http://www.amazon.com/gp/aw/reviews/B006UA7930

The link on that page took me to their older, blue-topped, Chinese-made model which did suffer from quality issues. Production has apparently been moved stateside to produce the newer red top models which have a much better reputation.

 

[semipro]

OP, one thing you could do to get some extra "apparent" capacity from a standard 50 Gal unit is to run it at a higher temp and then use an external tempering valve to mix cold water with the WH output to get it to usable temps.
This will result in some loss of overall efficiency due to heat loss with from a higher temp differential between in tank and outside the tank.

 

[fbelec]

tried that on the job worked great for back to back showers but not the jacuzzi

 

[drz1050]

The link on that page took me to their older, blue-topped, Chinese-made model which did suffer from quality issues. Production has apparently been moved stateside to produce the newer red top models which have a much better reputation.

Glad to hear this.. hopefully they keep it up!

 

[Don2222]

Hello

Here are pics of the ECO Smart install that I like.

https://www.hearth.com/talk/threads...tion-pics-good-efficient.143673/#post-1939310