On Fri, 27 Jan 2006 04:45:10 GMT, "Craig Robison"
:> Craig Robison wrote:
:>> I have a perfectly good 40 gallon Natural Gas water heater (in the attic)
:>> it sometimes proved to be insufficient with company in town so I did what
:>> you should not do and cranked up the temp to about 145-150 and it seemed
:>> to help although we still ran out during times of heavy use. Now we have
:>> a kid on the way, water is SCALDING HOT and we are going to need more of
:>> it anyway. Long story short I found that it was cheaper to add a second
:>> 40 gallon water heater (plenty of room) than to replace the existing one
:>> (I hated the idea of removing a good water heater, it is only 5 years
:>> old). Also, I went electric instead of gas, mostly because I did not
:>> want to cut a hole in the roof for the vent AND the electric model was
:>> cheaper AND I just happened to have a no-longer-used 10 gauge wire
:>> running right to it. Natural gas prices are sky-rocketing but I still
:>> think that a gas water heater is cheaper to operate than an electric
:>> model SO, I plumbed them in series rather than parallel. That is to say
:>> the hot water leaves the gas water heater and goes into the electric
:>> water heater then into the house. In this manner I figure that the gas
:>> heater is still doing most of the heating and the electric one is more
:>> like a storage tank. I have set them both to 125 degrees, the minimum
:>> temperature that the dishwasher manual recommends (to do this I filled a
:>> bucket full from the T&P valve and took the temp right there). My
:>> question, is there anything wrong with having the water flow from one to
:>> the other in this manner? I cannot see why the electric water heater
:>> cares what temperature the inlet water is. For what it is worth the guy
:>> at Home Depot thought it was brilliant, but he aint a plumber, and
:>> neither am I...
:>> Any Thoughts?
:> I always had two gas heater in series. But have no experience with
:> gas-electric combo. I'd think they'll have different recovery rate.
:I agree, I suspect that the 3800 watt, single element, el-cheapo electric
:water heater recovers pretty slow. Compared to the 30K BTU NG heater...
:another reason I put them in series.
What I don't understand is setting them at the same temperature. If you
are going to do that I'd think you'd have the gas one before the
electric one and set the electric one's thermostat a little higher than
the gas. Then the gas one will do most of the work (which is what you
want). IOW, if you want 125 degree water, set the gas one to 110 or 115
and the electric to 125.