Point of use/on demand hot water heaters

[ultrarunner]

One caution as someone that has whole house on demand electric water heaters...

If you are anywhere subject to freezing temps a small tank type heater will prevent damage from freezing.

I've lost two on demand electric water heaters in the cabin since 1982.

 

[cat fever]

If your need for hot water in not "alot", I would go with a 6 gallon electric water heater. It will provide all you need and no freezing issues.

 

[downsizingnow48]

In our Virginia house I replaced an electric hot water heater with an on demand unit. It requires heavy wiring and copper pipe as mentioned. It worked perfect.

 

[Sodo]

If a tank water heater is within the heated envelope of the house, all the heat that "leaks" while you are "maintaining unused hot water" simply goes to heat the house, and your other heat source "runs an equivalent amount less". For example if the heater is in a closet, inside the house. If the tank-heater is in the garage, or in a crawlspace, the heat that leaks can be "wasted". However you might find some value in partially heating a garage with waste water heat, for a common example.

There can be substantial energy savings if your water heater is outside the home's insulated envelope. This would be an example where it might make sense to have an on-demand heater.

A relatives house was destroyed by a tank type water heater that failed while the house was unattended. The entire floor puffed up about 2 inches and its a mold hazard. Pretty sure it will be razed and the land sold. This would be a good example for the heater outside. And not leaving a house unattended with the water "on".

 

[dstig1]

Try Supplyhouse.com. They are awesome to deal with. Prices are really good, shipping is super fast (even ground), and great service if you need it. They have a few small on-demand heaters just for this purpose. I am planning to put one in for my shop similar to yours, one of these days. Use would be very intermittent so heating a tank of water all the time is silly. It sure isn't going to run a shower, but perfect for a single sink, IMO. For our house I put in on demand water heater for DHW and it is awesome. Mind you, it runs off nat gas, not elec, but it is great, even in this cold climate. Well water in the winter can get down below 50 here but 200k BTUs will heat that right up. It also is softened water, which probably will help a lot in longevity. Electric on-demand is a dicey proposal in many situations, but this single sink deal is tailor made for them, IMO.

 

[cat fever]

Sodo, many times when I am out of town for several days I will shut off the water for the reason you mentioned.

 

[Sodo]

I know its off-topic but I've been using this on-demand propane heater at my cabin for 2 years. It's perfect for a shop too. Its 75,000 BTU and has no problem with my incoming water temp 40*F. 75,000 is enough for a shower, we don't mix with the cold (single pipe), and don't run it full blast, its too hot for that. $210, uses gas from a 20lb tank, and no electricity. A wild guess is a 20 lb tank will give 20 good long showers. It uses two Dcells for ignition and its had the same batteries for 2 years. .

Eccotemp L10 Portable Outdoor Tankless Water Heater Eccotemp L1 Portable Outdoor Tankless Water Heater - - Amazon.com

Its pressure activated. You just open the water valve and the flame starts. And you will be a hero if you bring it to Hunting camp.

 

[Aquamoose]

I bought the cheapest 120v under sink hot water heater from HD, plumbed it, plugged it in and left it alone. It ALWAYS delivered hot water to wash my hands and can fill a small bucket with hot water if I needed to.

It's that simple, really. If you want more, there's a 30a 220v type that continuously delivers scalding hot water available. It's the size of a shoebox. I use it for my radiant floor system in my shop (36x48). Both of them lets you dial in the heat setting.

 

[Budweiser John]

Thanks for all the intel. I'm leaning towards a 220V on demand rather than keeping a tank type heater going all the time as there will be days, weeks, or even a month or so subject sink would go unused.
No need for scalding hot water just want to raise the temp to something more comfortable than 47 degree well water. We are fortunate in that our water is not super hard.

 

[EddieWalker]

When I was in South Africa, one of the camps we stayed at had a propane on demand water heater that was awesome. They had a fairly large tank sitting right out side the bathroom that the hauled off to fill when needed. I'm going to guess that it was close to ten gallons, but I don't really know. It was a lot bigger then the ones on Bar B Q's.