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I'm replacing board on Lennox 80uhg4-75a-3 and can't find…

Customer Question
I'm replacing board on...

I'm replacing board on Lennox 80uhg4-75a-3 and can't find e20 on new board (hum-h)

Contractor's Assistant: I'll do all I can to help. How long have you been dealing with this?

20 min

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

Yes

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

Can't think of anything

Submitted: 8 months ago.Category: HVAC
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Customer reply replied 8 months ago
Hello?
Customer reply replied 8 months ago
Also there is another box on the current mounting bracket that I'm not sure about, and the new board has a circuit breaker that I don't know where it goes
Customer reply replied 8 months ago
Is this question still active?
Answered in 1 hour by:
11/10/2017
HVAC Technician: gotoman for ac, HVAC Technician replied 8 months ago
gotoman for ac
gotoman for ac, HVAC Technician
Category: HVAC
Satisfied Customers: 5,349
Experience: 51 years of experience install design and repair of all makes and models of AC
Verified

Russ here. What is the part number of new board. Russ

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Customer reply replied 8 months ago
83m00
HVAC Technician: gotoman for ac, HVAC Technician replied 8 months ago

The circuit breaker goes in the 24 volt power line from transformer. What part are you not sure of besides breaker. Russ

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Customer reply replied 8 months ago
Is that the blue wire coming from transformer? The connector is too small to connect to circuit breaker
HVAC Technician: gotoman for ac, HVAC Technician replied 8 months ago

Let me pull wiring for the 80. Russ

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HVAC Technician: gotoman for ac, HVAC Technician replied 8 months ago

Checked wiring. Id connector is to small for circuit breaker just use on of the extra wires with a larger spade. Blue is the correct wire to install circuit breaker. Russ

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Customer reply replied 8 months ago
Sorry Russ not sure what you mean. They did include extra blue wire but the connectors are too large to fit on transformer. Do I need to clip and install the bigger connectors?
Customer reply replied 8 months ago
Sorry I meant install smaller connectors
Customer reply replied 8 months ago
Also I'm really not sure if I wired this correctly, it is a different board and I just used the E designations (E8 etc). Would they be the same on the new board? Old board had e20 which I could not find on new board. It is the HUM.
Customer reply replied 8 months ago
Lastly, the new bracket they included with the board doesn't have enough room. For the transformer, is there any harm in just sticking the new board on the old bracket (only one stand off connector lines up though so board is uneven and back is touching the bracket
HVAC Technician: gotoman for ac, HVAC Technician replied 8 months ago

Let me check connections

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HVAC Technician: gotoman for ac, HVAC Technician replied 8 months ago

No harm as long as the board is secure. The hum is humidifier connection actually an accessory connection. What color wire went to the E 20 connection

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Customer reply replied 8 months ago
Black
Customer reply replied 8 months ago
I plugged it into the HUM marked port on the new board. I didn't do something right because I tried to fire up the furnace and it never turned on. Thermostat powered up but the fan or gas never came on. I took a picture of the colored wiring but forgot that there are two red wires, one went to R and the other went into same port as yellow. I might have gotten the two reds mixed up.
Customer reply replied 8 months ago
One of the reds was bundled with a white wire. Is that the one that goes into Y along with the yellow wire?
HVAC Technician: gotoman for ac, HVAC Technician replied 8 months ago

See if the red goes to outside unit. It will be a separate thermostat wire with one wire going to Y and the other going to C terminal. Russ

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HVAC Technician: gotoman for ac, HVAC Technician replied 8 months ago

If you can take photo of board and attach. Russ

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HVAC Technician: gotoman for ac, HVAC Technician replied 8 months ago

Black on heat goes to cool. Brown on Park goes to Heat. Russ

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Customer reply replied 8 months ago
Ok I'll try that. Any harm in testing it without the circuit breaker? I need to get connectors tomorrow but want to switch wires and try tonight
HVAC Technician: gotoman for ac, HVAC Technician replied 8 months ago

Really need that circuit breaker inline to protect transformer. Russ

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Customer reply replied 8 months ago
Ok I'll need to pick it up in the am then, need a Home Depot run
HVAC Technician: gotoman for ac, HVAC Technician replied 8 months ago

OK let me know. I will be here. Russ

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Customer reply replied 8 months ago
Hi Russ. Switched the black and brown and installed the breaker. Turned on the furnace and it looks like the thermostat is calling for heat but the furnace isn't kicking on, no fan or gas
Customer reply replied 8 months ago
Think I found the problem...nothing hooked up to FAN. On YouTube they guy hooks up a red wire. I found a red wire but I don't think it was hooked up on the old board. Here is a pic
Customer reply replied 8 months ago
I have blue going to EAC, but I don't have an air cleaner so I'm guessing this is the one that goes to FAN?
HVAC Technician: gotoman for ac, HVAC Technician replied 8 months ago

Yes you can connect blue to fan. That is for continuous operation.

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Customer reply replied 8 months ago
Just checked the other furnace board (we have two). Black goes to cool, yellow goes to heat. Red and brown go to park. Can't find a blue wire on the other board. Should I try yellow to heat?
HVAC Technician: gotoman for ac, HVAC Technician replied 8 months ago

The brown is a speed on fan . Blue on most motors. Is furnace working. Russ

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Customer reply replied 8 months ago
No i tried but it's freezing here in philly so I had to call someone in. They are here now
HVAC Technician: gotoman for ac, HVAC Technician replied 8 months ago

Most likely a jumper wire was not installed. Russ. Please let me know.

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