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I've got a Honeywell Chromotherm iii thermostate that has a…

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I've got a Honeywell...

I've got a Honeywell Chromotherm iii thermostate that has a -AC code showing up. I've flipped the furnace breaker , turned fan on manual but no juice to furnace. I have a Rheen Corsaire furnace.

Contractor's Assistant: Just to clarify, do you think this is a larger HVAC problem, or something specific to the thermostat?

Not thermostat. No power to furnace. Is there a fuse on the furnace?

Contractor's Assistant: Do you plan on doing the work yourself?

Yes

Contractor's Assistant: Anything else we should know to help you best?

I don't think so

Submitted: 7 months ago.Category: HVAC
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Answered in 5 minutes by:
12/14/2017
HVAC Technician: HVAC Guru, HVAC TECH replied 7 months ago
HVAC Guru
HVAC Guru, HVAC TECH
Category: HVAC
Satisfied Customers: 18,712
Experience: 20yrs in the HVAC industry with certificates and degrees.
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One moment please..Note it takes time to type and add links so please be patient. Also the site will send you a phone call offer, that is not me.

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HVAC Technician: HVAC Guru, HVAC TECH replied 7 months ago

What likely happened is the low voltage fuse in the furnace or airhandler blew. There typically is a SLOT STYLE 3-5AMP FUSE on the board itself inside the furnace/airhandler like this.

CLICK HERE

If that is burned out all power to the thermostat will be lost. 95% of all units use some sort of SLOT FUSE or inline BUS STYLE FUSE to protect the low voltage circuit. You need to find that and change it out. If you just bump two wires together you could have just popped it without even knowing it. Now if for some reason your unit does not use a fuse often the board will be damaged due to the short. You would need to confirm you have 24 volts to the board inside the furnace/airhandler with a volt meter to make sure though.

Note if you have a condensate pump check the float and make sure the pump is not full of water...as that could cut low voltage power to the unit as well if the pump is not working and full of water.

All I ask is please use the....FINISH BY RATING link at the top your page to select a 5 STAR RATING before leaving today....this is important for my status on the site plus without a rating I will receive ZERO credit(NO PAY) from the site for assisting you. Also rating now does not close the question out and you can come back anytime for FREE right here to me......Happy Holidays!

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Customer reply replied 7 months ago
does the rheem corsaire have a fuse? i dont see one
Customer reply replied 7 months ago
That's it one? one answer, this stinks
HVAC Technician: HVAC Guru, HVAC TECH replied 7 months ago

No what else did you need?

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HVAC Technician: HVAC Guru, HVAC TECH replied 7 months ago

Take a pic of the board and upload it here please

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Customer reply replied 7 months ago
I asked if my furnace had a fuse or not. I do not see one
HVAC Technician: HVAC Guru, HVAC TECH replied 7 months ago

Do you have the complete model off the tag on the furnace

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Customer reply replied 7 months ago
It's a Rheem corsaire
HVAC Technician: HVAC Guru, HVAC TECH replied 7 months ago

Do you see the board and the LEDs on the board, if so are any lit up?

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Customer reply replied 7 months ago
there's no leds on the board
HVAC Technician: HVAC Guru, HVAC TECH replied 7 months ago

OK most Corsaire units have them if yours does not do you have a volt meter?

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Customer reply replied 7 months ago
no
HVAC Technician: HVAC Guru, HVAC TECH replied 7 months ago

Can you see the low voltage transformer?

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Customer reply replied 7 months ago
Nevere mind
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