Tankless Water Heaters

[Dan Mages]

Hi again.

I have a Bosch Aquastar 125hx tankless water heater on order and I am wondering if anyone has one or a similar unit. What do you think of it? How much do you save in gas with it??

thanks!

Dan

Now to go by my neighbor a case of quality beer for helping me install it. It's a tankless job, but he's willing to do it...

[Joe Mioux]

I have a e.l.m Aquastar instant water heater. I have had it out in one of the greenhouses for 15 years. It works great. I don't keep the pilot light lit all the time though. We only use it during the cold months.

It has worked just fine and I have no idea how much money this thing saves.

JOe

[Steve Clardy]

I wanted to put a tankless in our bathroom addition in the bedroom, but our local plumbing supplier that handles those, discouraged me from them. Due to the lime buildup in the heater itself. He said they had a lot of trouble in this area.
So I went with a small 30 gallon electric. Just a shower and vanity in there.

[Hal Flynt]

I have a Takagi big enough for 2 showers. I know I am saving gas, but not sure how much yet as we are on a fixed amount billing which will up for review soon. We are empty nesters and I like not paying for hot water when away.

The real reason I got it , was that it made room to put my thickness planer where the tank had been.

[Dan Mages]

I wanted to put a tankless in our bathroom addition in the bedroom, but our local plumbing supplier that handles those, discouraged me from them. Due to the lime buildup in the heater itself. He said they had a lot of trouble in this area.
So I went with a small 30 gallon electric. Just a shower and vanity in there.

Lime build up is a concern, so I am throwing in a GE whole household water filter. It will filter "silt, sand, sediment, and rust" and should hopefully take care of the lime problem. It is only $35 at the Orange Borg.

Dan

[Tom Mullane]

I have considered a tankless heater sometime in the future when the one I have finally goes south... but do they make them in electric... danged house is all electric.. I hate it... already got a good water softener system to take care of lime and minerals..

[Jim Becker]

The 125 is a "one thing at a time" unit, but has a good reputation from what I can see. The larger 240 (made by Tagaki) would be my choice if you need to service more than one location simultaniously. The only reason I don't have one in the house now is that I couldn't satisfy the venting requirements due to the nature of our house. (Had to use a high-efficiency tank unit to deal with it) But I'll have one in place for the addition we have planned.

[Frank Hagan]

Lime build up is a concern, so I am throwing in a GE whole household water filter. It will filter "silt, sand, sediment, and rust" and should hopefully take care of the lime problem. It is only $35 at the Orange Borg.

Dan

Well, maybe. The problem may be the hardness of the water in your area. If you are on a municipal supply, and not a well, your local water company should be able to tell you what the water hardness is ... usually expressed in "grains per gallon" or "parts per million". Or, you can buy a water testing kit to find the calcium hardness. There are occasionally other factors ... total dissolved solids in the water, or things like collodial clay, but usually problems are due to hard water. Anything above 9 or 10 is usually too severe for the tankless appliances, and they may lime up (check with the manufacturer; my company doesn't recommend installation of appliances with small heat exchanger tubes in water over 10 grains per gallon). Very soft water can also be tough on copper waterways in the heat exchanger, so if your water hardness is low ... under 5 grains per gallon ... make sure you have a stainless heat exchanger. Many of the tankless appliances have them.

You won't save a ton of money with these. My 50 gallon tank-type water heater will use an average of 278 therms each year, and at .90 a therm, that's under $300. Most of these tank-type units are advertised at 82% efficiency, but in reality they quickly fall to under 80%, and toward the end of their life might be down to 76%. The tankless water heaters may be as high as 96% efficient, and should remain that efficient throughout their life span. The most you will save is about 20%, or $60 per year.

There are exceptions ... if you have a long run from the tank-type heater, and you install the tankless near the demand, you can save more. And you might be able to save on installation in new or retrofit situations where the side wall venting of the tankless models makes them very handy. But otherwise you have to decide if the $60 per year savings is worth the difference in cost (and for those who care, buying foreign rather than north American made products).

[Frank Hagan]

I have considered a tankless heater sometime in the future when the one I have finally goes south... but do they make them in electric... danged house is all electric.. I hate it... already got a good water softener system to take care of lime and minerals..

Your electric water heater has an even higher efficiency rating than the tankless type. The energy may cost more right now, but that could change.

[Bill Lewis]

Well, maybe. The problem may be the hardness of the water in your area. If you are on a municipal supply, and not a well, your local water company should be able to tell you what the water hardness is ... usually expressed in "grains per gallon" or "parts per million". Or, you can buy a water testing kit to find the calcium hardness. There are occasionally other factors ... total dissolved solids in the water, or things like collodial clay, but usually problems are due to hard water.

In other words, a filter will not and can not remove disolved solids from your water. This can only be done by distallation (which a water heater is), chemically, or through reverse osmosis.

[Frank Hagan]

In other words, a filter will not and can not remove disolved solids from your water. This can only be done by distallation (which a water heater is), chemically, or through reverse osmosis.

There are also chemical treatments that sometimes work to protect the tubes regardless of the water hardness or TDS levels. But for the most part, I think you're right ... if you are over 10 grains per gallon hardness (or whatever the manufacturer says), you should probably not install the tankless water heater.

[Stu Ablett in Tokyo Japan]

Here in Japan it is rare to find a Tank water heater, we all use the Tankless water heaters.

The unit we have is a natural gas fired one, and it puts out tons of hot water on demand. It is about 2' from the shower/bath and about 10' from the kitchen sink and maybe 6' from the bathroom sink. It works a treat, I don't know how much money we save over a tank unit, but because it is gas and not electric it is cheaper. The only tank water heaters I've seen hear, of any size, are all electric.

The unit we have also does our radiant flooring, this uses a fluid like antifreeze.

Not to change the subject, but the radiant flooring is just so great, we seldom use the heatpump AC in the winter with the radiant flooring, and as it is on a 24h timer we find it very easy to live with.

Cheers!