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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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Question furnace house. Heat cool switch on furnace and put

Customer Question

Question Coleman furnace house. Heat cool switch on furnace and put a thermostat on and has heat cool and the AC runs whether there's a thermostat on the wall up the ball and someone got two wires from thermostat the other two wires go down to the condenser is there anyway to bypass all that crap
JA: Did you check the furnace's filters?
Customer: It runs all the time with no thermostat hooked up on the wall on cool
JA: Do you plan on doing the work yourself?
Customer: Yes I am HVAC certified haven't had one do this before
JA: Anything else we should know to help you best?
Customer: Like I said it has two wires red and white going to the stat I put a bobo thermostat on it and is he cool on off no matter from starts on the wall off the wall ac constantly runs because it has that switch on is for heat and cool on calming is there anyway I can bypass all that and then you start wire
Submitted: 1 month ago.
Category: HVAC
Expert:  airheatman replied 1 month ago.

Give me a few more details/

1.Is this in a mobile home?

2.Did you just move here?

3Can you attach photos of this setup? (thermostat,swicth and furnace?)

Customer: replied 1 month ago.
it's mobile home no I don't live there that's my sister's place it's been doing it for a while when it's on cool if Rhymes Rhymes runs at very don't shut off it has a red and white wire coming from the lower one that's an older Coleman it has a switch for cold heat on furnace not put a Braeburn thermostat on it that has heat cool off and the AC will not shut off when it gets to room temp I'm wondering can I bypass that switch on the furnace to run a new start wire to make it like a regular furnace would work
Expert:  airheatman replied 1 month ago.

OK now here is the reason I ask.Normally in an older mobile home installation, there will be two thermostats mounted on wall.One for heat with only two wires fed from a transformer in furnace and then a second thermostat for ac with at least 3 wires fed from a transformer in the outdoor unit.Are you there now?

Customer: replied 1 month ago.
Now she's in bed
Expert:  airheatman replied 1 month ago.

We can definitely convert whatever is there to work with a single heat cool thermostat if you have the patience and can follow my lead.

Customer: replied 1 month ago.
You can send me what to do I will do it tomorrow afternoon when I get off I can follow your instructions step by step
Customer: replied 1 month ago.
I do have the model number I can send you
Expert:  airheatman replied 1 month ago.

Pictures speak volumes so if you can take pics at attach here using the attach files button would be a great help.

Here is what I need.

1Pictures of thermostat and wiring

2.Picture of the heat cool switch on furnace

3.Model on furnace and outdoor unit

4. A picture of the components in outdoor unit with cover removed.

From there I can easily guide you.Go ahead and give me furnace model since you have it

Customer: replied 1 month ago.
Model number is *****
Expert:  airheatman replied 1 month ago.

A picture of the furnace wiring diagram will help if you can get that.I have the DGAT wiring diagram but not the rt(not sure how much difference there is)

Customer: replied 1 month ago.
Ok can I text you when I get over there tomorrow afternoon
Expert:  airheatman replied 1 month ago.

Do you know if furnace has a control board like this?

Customer: replied 1 month ago.
Not that one
Expert:  airheatman replied 1 month ago.

If it has a control board this would be how to wire.

As much of the info you can get and pics will be a great help

Customer: replied 1 month ago.
No It Dont have a board
Expert:  airheatman replied 1 month ago.

OK, we should be able to make it work anyway I just need to see wiring and components.It will be same principle.

Customer: replied 1 month ago.
Tomorrow afternoon be fine
Expert:  airheatman replied 1 month ago.

Sounds good. Meanwhile take a look at this link and it may be helpful.Look forward to helping you

Scroll down to the section that discusses connecting thermostat