When to go tankless?

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Old 02-05-14, 12:25 PM
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When to go tankless?

I've done some looking around and am having a hard time understanding when a tankless boiler is a good idea (for a hot water baseboard house). As far as I can tell, the only reason people do tankless is to have unlimited hot showers. But it seems to me that the boiler will run the same amount of time whether you have an indirect tank or tankless, thereby not really saving money either way. What am I missing?
 
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Old 02-05-14, 01:53 PM
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Don't confuse those wall-hung modern 'tankless' water heaters with a " THANKLESS coil " water heater installed inside a boiler.

In my (and most everyone else's opinion) there is NEVER a good reason to heat domestic water with a 'thankless coil' in a boiler.

Our Friend Furd is Fond of saying that the only thing worse is heating water in a kettle on a wood stove.

As far as I can tell, the only reason people do tankless is to have unlimited hot showers
Maybe with a brand new coil, and a low flow rate... you MIGHT be lucky to have unlimited hot shower... but after a little bit of lime builds up inside the coil (which almost always happens), there will be NO 'unlimited' hot water.

No, there is no good reason to consider it.

FAR more fuel will be burned keeping a boiler at 140-150 degrees 24/7/365 for a few gallons of hot water use a day than you would by heating a 40 gallon tank of water and then the boiler shutting down for hours on end before it needs to reheat the tank.
 
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Old 02-05-14, 02:55 PM
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OK, that makes sense. I didn't know there were two different items that used the word 'tankless'.
 
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Old 02-05-14, 04:21 PM
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With the price of my only fuel choice (oil) these days, it makes sense to go with electric water heater (for me). If I had natgas available I would definitely choose an indirect.
 
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Old 02-05-14, 04:23 PM
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OK, that makes sense. I didn't know there were two different items that used the word 'tankless'.
Actually there are wall hung units that are boilers to heat the home that look just like the tankless models for hot water...

Additionally there are como units that heat the home and produce hot water for the faucets...

These units are far superior of the cast iron boilers with a tankless coil installed...

Hope this makes more sense....
 
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Old 02-05-14, 05:22 PM
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I believe you are talking about the high efficiency wall hung tankless water heaters. If so there are two basic types. The tankless water heaters made by water heater companies and combi units made by boiler companies. The main difference is the combies will supply more heating btu's and less dhw gpm. The tanless will supply more gpm flow and less btu's of heat.
I feel the taklless high efficiency water heaters are good when you are limited on space, don't have a boiler, your not on a well unless you treat your water and can do your own service and cleaning.
You can't beat an indirect water heater tank with superior insulation giving you 1/2f per hour standny loss. Heating still water is much easier than heating moving water. Life cycle cost is much less.
If you did mean a tankless coil in a boiler there is never a good time to use them.
 
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Old 02-05-14, 06:08 PM
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I believe you are talking about the high efficiency wall hung tankless water heaters...
I actually was referring to a tankless coil inside a boiler.

My parents have a tankless coil boiler (oil), and I was trying to figure out if going to an indirect tank setup or keeping the tankless coil type when this one dies makes sense. Natural gas is not available in the area, otherwise I'd push the mod/con boiler and indirect setup like I have.
 
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Old 02-05-14, 06:47 PM
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Go indirect you will not be sorry.
 
 

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