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Tony Hwang Tony Hwang is offline
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Default How to test a wall thermostat to see if it's actually working?

Danny D'Amico wrote:
On Tue, 10 Dec 2013 18:10:46 -0600, philo wrote:

If the blower is working that means the furnace is getting power.
Unless you know /exactly/ what you are doing, a furnace is one thing
you should not fool with.


The fact that I assume 120 volts (and whatever the high-tension leads
have in them) is there, is the key reason why I'm not just jumping
leads just yet.

I want to *measure* first. That's not dangerous. Jumping things is
much more dangerous (if I make a mistake).

So, at the moment, I concentrated first on identifying all the parts
of the furnace (which I snapped a picture of and posted separately).

Then, I am concentrating on figuring out how those parts play together.

After that, I'll do the measuring.

And then the jumping.

I'm sorry I'm probably way slower than you guys would like, but, I'm
trying to actually understand the darn thing first ... Thanks for
your patience. I've still got to read that Carrier manual ...

Hi,
Jumping is involved with 24V AC control voltage. Not dangerous.
Let me ask you, can you read schematics? Can you id. parts in the
furnace like piezo ignitor, limit switches(some are NO, some are NC),
do you understand relay logic? First thing I suggested you was to reset
the furnace by powering it off/on. Gently tap all the relays you can
see. Am\nother issue may be you may have messed up the 'stat when you
open it and reassembled. We're going around same routine when you had
alarm trouble wating lot of time.