I just started thinking about getting an electric water heater timer for my
3 year old 30 gallon water heater. I checked some of the reviews for the
Intermatic timers and it looks like everybody loves them and they say they
practically get their $40 bucks back each month.
Are timers all they seem to be cracked up to be and will turning off the
water heater from 10 PM to 8 AM really save a family of 4 a big chunk of
change each month?
I've turned off the electricity to my water heater and it stays pretty
hot for 3 days iirc. And it would stay hot a lot longer if I weren't
using the hot water. The major thing cooling off the water is the
cold water going in when I use hot water.
Usage is very strange. I went away for November and December (and my
billing periods were from the 15th to the 14th, and my bill was almost
the same as the previous year when I was here the whole time.
The water heater was off, and empty. The furnaace was down to about 45
and it's oil so it only used electricity to run the ignition and
blower, and the furance fan.
About 4 lights were on timers, but I leave 3 of them on timers even
when I'm home.
It was not an estimated reading.
I still haven't figured it out.
A very clever timer and a well-programmed family might save significant
energy if it turned on a half-hour before the first use of the day and
turned off before the last use, an hour later, leaving itself entirely
filled with cold water for 23 hours per day.
What about me?
My WH is on for one hour daily (manually, when I get up in the AM). I take
my shower and wash dishes, then shut it off . There's still enough residual
hot water during the day for hand washing, etc. My clothes washer is only
used with cold water.
And there you go again, with another silly statement that defies
physics. You yourself gave an example where you stated:
"Let's say your HW is at 130 degrees, and it cools to 110 overnight in
And now you say the temperature doesn't change at all? Or that it
matters if the water is used or not? You are totally confused. By
keeping the water heater from coming on during the night and reheating
itself, energy is saved. Period.
The heat loss from both the house cooling slighltly over night and the
water heater cooling slightly over night are both unintentional. Not
that it makes any difference, as if the physics depend on what is
intentional or not. It's this simple: The rate of heat loss is
proportional to the temp difference and applies in both cases.
Well, duh! That's like saying you won't save any heat in a house by
setting back the temp at night and then following it up with the
disclaimer that you're intentionally ignoring the heat loss curve
because it's not significant to the question. In fact, it's the
As I estimated yesterday, he could save about eight cents,
Number pulled wildly from the air, while you completely ignore the DOE
that had an estimate of 5% at the low end. You think mabye the DOE
knows and has tested things more than you?
Sure it stops at equilibrium. So what? That doesn't mean you aren't
saving energy at a lower than normal temp. Or that you aren't saving
as the temp drops to it's final temp. Gheez, if that were true, with
it 20 deg outside, the only way you'd save any energy would be to have
the jacuzzi drop to 20 deg and freeze solid. Or that to save energy
with a setback thermostat in a house, you'd have to let it go down to
20 deg inside. Yet, we know that in both those cases, going to a
lower temp does save energy. Exact same thing with the water heater.
Now, I'm actually starting to get annoyed. You asked for references
that said using a timer on a water heater works to save energy. I
gave you 3. The DOE, the state of California and Popular Mechanics,
which seem reasonable and credible. All 3 state that installing a
timer on a water heater does save energy and recommend doing it.
And your response? You just ignore it.
Where are your references that back up any of the silly nonsense
you've stated? I'd especially like to see one that talks about air
being "used" as essential to saving heat in a home by setting back the
thermostat at night. Or one that says you only save energy when the
heated object coolst to it's final temp. Or one that talks about the
heat loss having to be intentional vs unintentional. Do a google on
any of these topics and show us where we can find it.
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