Electric water heater for space heating

[Christoph]

I have recently come across a couple of radiant heat systems that are being heated using a 50 gallon electric water heater. Is this legal? Is this ok to do according to code? The systems I have seen have been working fine for years, I was just wondering if this as ok to do or not.

 

[johnjh2o]

As long as the demand for heat is low enough that the heater can supply it, it should be fine. It may be a little costly to run. You would be better off if it was a gas heater.

 

[Christoph]

Thanks for the quick reply! Actually electric is one of the cheaper ways to heat our homes in my area, as we run off of hydro power and don't have natural gas. I know that they work in the examples I have seen, but my biggest question was whether or not it was code. My local inspector wasn't sure if it was ok to use an appliance that is listed for potable water heating for a closed loop heating system. Thoughts?

 

[chukar]

As long as it has a double wall heat exchanger inside of it, then yes I would be legal, if its a regular electric with no separate heat exchanger then probably not. Attached is the Laars with a picture of what I mean

http://www.laars.com/LinkClick.aspx?fileticket=C3JL-acRwm8=&...

There is always the possibility that someone could come put chemicals into the system, also the reason they prefer a proper back flow device on the feed for it.

 

[Caduceus]

I'm not promoting this specific manufacturer, just using the images on the site as an example that there are electric indirect water heaters for hydronic systems on the market, since you don't have natural gas as an option.
http://www.heat-flo.com/prod_indirectWaterHeater.html