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Installing a new furnace and the unit came up with anA12…

Customer Question
Hi, installing a new...

Hi, installing a new furnace and the unit came up with anA12 code. Any idea what that means?

Contractor's Assistant: Did you check the furnace's filters?

Yup

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

Have acontracterhere that is struggling with the install

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

It's a 4 wire install for a 2 stage furnace.

Submitted: 10 months ago.Category: HVAC
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Answered in 6 minutes by:
9/24/2017
HVAC Technician: Phil, Mechanical Engineer replied 10 months ago
Phil
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 7,426
Experience: Retired HVAC/ Electrical & Boiler contractor. Industrial
Verified

Hello, I need the brand and model number of the furnace to pull the manual on it.

Meantime tell me what numbers or letters are on the thermostat terminal strip inside the furnace that you used, and the same information on the wall thermostat,

We can go from there

.

OPENING STATEMENTS

Important note about RATING my work:

I am a retired mechanical engineer and HVAC/electrical/ refrigeration and boiler contractor ... with 56 years in this business. The last 20 of those years consulting for major firms nationally.. and with over 8,000 questions answered here since 2009, with a 98.5% satisfaction rating.

.

All I ask is please respect me and my input by selecting the***RATING LINK***at the top of your page, that is the only way I am credited through the site. Rating does not affect your charges nor ability to refund if not satisfied.

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If you need to be coached through a full diagnosis/repair,and wiring etc. for up to two days, and wish to be trained to use test instruments...... that goes well beyond' Just a simple Answer' of course, and goes beyond what most other experts here offer.....rate my answer so far positively.. . and I will deliver that training and coaching to you All on the same dime so to speak.

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Lacking a positive rating I can spend days helping a person at my own expense and loose my shirt, shorts and socks on the deal.

.

Attach a close up photo of the wiring diagram glued to the inside of the blower access door and I will mark it up with trouble shooting instructions then follow up with step by step training and coaching until you have a solution.

.

Photo must be exceedingly well focused. Use the 'add files' link next to your send button to get the photo to me.

.

Phone call offers:

If you wish to accept the companies $25 phone call offer, if indeed they send you one, this will go a *lot faster, but it IS 100% optional... or we can continue here in this dialog box at no additional charge.

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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 7,426
7,426 Satisfied Customers
Experience: Retired HVAC/ Electrical & Boiler contractor. Industrial

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