I recently bought a new thermostat for my Heat Pump system and I want
to install it. Problem is, that I've turned off EVERY breaker in my
circuit box and I still get numbers on my thermostat. I turned off the
"HEAT" breaker, and the system doesn't come on if you mess with the
thermostat, but I don't want to pull at any wires if there's still
power to it.
Is there another breaker outside? (its a heat pump system with
Is it safe to change the thermostat, even if I still have numbers on
the LCD? is it REALLY that much electricity?
The new "setback" thermostats have an internal battery. Check the
instructions. My heat pumps (code issue, I believe) have disconnects
outside, as well as going through a breaker on the inside, which is
The original thermostat doesn't have room for a battery, so its running
straight from AC, unless its BEHIND the circuit board and I have to
unscrew it from the wall first (doubtful)
The thermostat I'm replacing is a White Rodgers Model. Looks to be
original, thought the furnace is new.
WAIT! I just discovered another breaker in the furnace closet. Will
THIS turn off the thermostat even though it appears to be for the
furnace only? I don't want to just switch it off and on a bunch of
Well, did turning that breaker off, kill the LCD display? Since you
said you had a heat pump, I assume by furnace you mean the
Air Handler? Many thermostats are powered by a stepdown
transformer in or near the air handler. I recommend that
you open the thermostat panel and measure the voltage on
the wires. your new Thermostat MUST match this voltage.
On 27 Jul 2006 16:24:46 -0700, email@example.com wrote:
So did the setback thermostat I bought 23 years ago. IIRC, I've only
replaced it once, because if the AC power is on, the battery isn't
needed. And my thermostat has mechanical switches for the times of
day, the day and night temps, and the days that there should be 2
setbacks instead of 1. So all the battery does is keep the time, when
the AC is off.
I wish I could help you more, but I do want to ask, If you are willing
to turn the power off altogether, why do you not want to turn it off
and on a few times for the sake of testing?
Or better yet, call the power company and tell them there is a
terrorist living next door and he has a large bomb hooked to the the
electrical system, and would they please shut down the power to the
entire city...... They will shut it down quickly, and when the police
arrive they ought to be happy to commit you to the psycho ward. But
before the cops arrive, you can safely install your thermostat without
getting a shock off that AA battery.
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