# Tie-in of a Coleman electric furnace



## trollmastergeneral (Dec 19, 2006)

how old is this unit?is this a mobile home unit? The reason I ask is because coleman used to make a residentual unit but I beleive they only make mobile home units know. The info you are looking for is not on the inside of the service doors by chance? If you cant find the schematic and post the model and serial number I should be able to get you a copy of the schematic.


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## nilo (Dec 30, 2006)

*Re(2):Wiring Diagram for Coleman add on Heat*

Reply to TROLLMASTERGENERAL's response:

There is a diagram on the inside of the electrical cover panel on the furnace -- the diagram is almost impossible to read because of deterioration on the drawing. The outside unit drawing on the inside of the electrical panel cover has been destroyed -- only a very small portion of it is readable.

I will have to check on the nameplate for an age on the furnace. I think it is about 20 years old, but not sure. This Heat Pump was added on later (see first post for model numbers). 

I went to a Mobile Home parts shop, and what they gave me does not tell me how to tie this furnace thermostat wiring into the thermostat and outside unit 24v. wiring. They don't have a serviceman -- they just sell parts and new units.

This reply is probably not much help, is it? But thanks for replying.


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## trollmastergeneral (Dec 19, 2006)

hey nilo did you guys replace the thermostat and it didnt work or why did someone tell you wire in 24 volts.


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## nilo (Dec 30, 2006)

*Re(2):Wiring Diagram for Coleman add on Heat*

Trollmastergeneral-

The Thermostat will turn the furnace on when it is switched to heat and the temp is turned up. The wiring is low voltage wiring @ 24.v, I checked with a meter. And I understand enough about the system to know that the system is controlled by the low voltage throught the thermostat. I have been trying to get the outside unit running instead of the heaters on the furnace when the thermostat is turned up. 

The guy (and it wasn't me) that took all of the wires apart at the furnace told my friend just to tie them back together color for color. We did that but the outside unit will not come one. I jumpered two low voltage furnace wires to the outside unit and it would run, but the outside unit will not run when the wiring is tied in on a wire for wire color basis as the man said to do. This fellow SEEMS to be impossible to get hold of now. It would have been relatively simple if he had left a drawing or had marked where each wire from the furnace was connected to the 24v. wires. 

Do you think that the thermostat is the problem? Or do you think that I am not explaining myself well enough? Thanks for responding.


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## trollmastergeneral (Dec 19, 2006)

I was trying to determine why the wires were ever taken apart.Was the unit not working and a service person came out or did he just notice one day the heat pump did not work? Is this a heat pump with electric back up heat. how many and what colors are comming from the thermostat


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## nilo (Dec 30, 2006)

*Re(2):Wiring Diagram for Coleman add on Heat*

Trollmastergeneral-

I don't know why the wiring was taken apart. All I know is that they weren't getting heat. This guy came in and took all the low voltage wiring apart and then hooked the furnace up to the thermostat wires and got the furnace heaters running so that they could have heat. 

My friend just knew he didn't have heat, and now he does. But this heat he is getting is from the heaters on the furnace, not from the heat pump outside. So here am I in the middle of trying to get the heat pump to run through the thermostat wiring. I know that the furnace heaters are to be on when the outside defrosts -- thats only common sense that you have a heat supply while the outside is defrosting and the air coming inside is AC air not heated air.

And there is a emergency heat switch on the thermostat, obviously for those heaters when the outside unit cant keep up. I do know that much, at least it makes sense to me. But every thermostat wiring combination I have tried doesn't get the outside unit to come on when it is tied into the thermostat wiring. There may be something else wrong, but for now, I am just trying to get the wiring straightened out.

If there were something wrong outside, wouldn't the furnace blower come on and run even if the outside unit would not start up? And the inside heaters would come on if the thermostat were switched to emergency heat....right?

If you have any diagram to offer, please do that. I know I'm imposing on you about this. And I appreciate your interest. 

It appears that I am going to have to just sit down with this unit and trace every wire to where it has been, and where it goes and determine its function. I am learning from other research what each wire color is supposed to control from the thermostat. But I just haven't found where I am missing on something. I have found in the meantime a diagram of the outside furnace that shows that low voltage wiring going to a furnace board, which this furnace doesn't have. Maybe I will work through it anyhow. 

If you decide that you can't help, I want you to know I do appreciate very much your effort. Respectfully, nilo


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## trollmastergeneral (Dec 19, 2006)

on your thermostat how many wires are connected . what are they connected too. If you could tell me what you have at your tstat outside unit and air handler I am pretty sure we could walk you thru it.


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## nilo (Dec 30, 2006)

*Re(2):Wiring Diagram for Coleman add on Heat*

I won't be able to get that info for a couple of days. The heat pump is several miles from where I live. I will go there Tuesday or Wednesday. After I get there and write down all the info and bring it home with me, I will send a reply then. 

I am going to make another effort on this thing when I get there. Who knows, I may work throught it, but I haven't so far.

Thanks, nilo


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## nilo (Dec 30, 2006)

trollmastergeneral said:


> I was trying to determine why the wires were ever taken apart.Was the unit not working and a service person came out or did he just notice one day the heat pump did not work? Is this a heat pump with electric back up heat. how many and what colors are comming from the thermostat


*Response from Nilo :* (1)I don't know why the other guy took the thermostat wires off. He was not a service person that I know of, just someone who got the heaters on the furnace to run when he did whatever he did. (2)Yes this is an electic furnace with as heat pump that was added on later. (3)The furnace has 4 low voltage wires coming out of it. Red(from transformer), Yellow(to the other side of the transformer), White (to the sequencers), and Green (to the blower relay). These I have traced to their connections on the furnace.

I don't know why he took the wires apart. when he could have run the funace on Emergency heat, right? Below is some info about what I have learned after going back today. 

*That information begins here. *

*Here is what I think: *I believe that the control board on the outside unit is bad. I can get the system to run by jumping the red and orange that come to the outside unit, where I jumped them to the contactor on the outside unit. I know the Orange wire goes to the reversing valve, but It read 24v. when checked against the Red wire coming out to the unit outside. 

The heap pump will run on heating with these jumpers on. These jumpers by-pass the control board. The outside unit will not run through the control board.

NOTE: I think I have some of the functions of the wires on the thermostat figured out. 

*(R) *Red= 24v.
*(G)* Green bower relay
*(O) *Oange=the reversing valve 
*(Y) *Yellow = contactor
*(X) *Black=?? (could this be the common wire?) 
*(W2)* White=??
*(B)*Brown - (Emergency heat?)
*(E) *no wire

*Here is what I did with the thermostat wiring:*
I connected the thermostat wires color for color to the wires going to the outside unit. Then I hooked the RED wire form the thermostat to the RED wire from the furnace transformer (to get 24v. to the thermostat). I hooked the Brown wire from the thermostat to the WHite wire on the furnace (this white wire traced to the sequencers. The Brown wire must operate through the lower mercury switch on the thermostat). The GREEN wire on the thermostat I connected to the Green wire to the furnace (blower relay), and hooked those two Green wires to the GREEN wire to the outside unit. The YELLOW frunace low voltage wire (the transformer common wire) I hooked to the RED wire going outside. All this came about after a lot of trial and error. 

When I turned the heating on, the outside unit came on, but when I removed one of the jumpers outside from the thermostat wires that I had jumped to the contactor, the outside unit stopped. So I left the jumpers on and it would run through the thermostat. By doing this jumpering, I by-passed the circuit board on the outside unit. Thats why I think this board is bad.

*Here are the furnace and outside unit and thermostat model numbers: [COLEMAN *ELECTRIC FURNACE model - EB17B], [OUTSIDE UNIT model - *COLEMAN *BRHQ0301BB], [THERMOSTAT model - *EVCON *3600-367A]. 

This heat pump was added on to this furnace, it did not come with the furnace originally. 

If you can't use this info, just email me [email protected] , and I will send send back the diagrams that I have obtained since you last reply. Thanks for all your trouble.........nilo


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