Gas Furnace issue, slightly chewed wire

Reply

  #1  
Old 12-18-12, 09:05 AM
Member
Thread Starter
Join Date: Dec 2012
Location: usa
Posts: 5
Exclamation Gas Furnace issue, slightly chewed wire

Hello and thank you in advance for any help.

I have a Amana Air Command 80 sse gas furnace and it has been working great up to now. There is an internal wire that comes out of the metal housing on its left side along with the power cable. This wire bundle goes into the thermostat and has 4 separate small red, blue, white, green wires inside of it.

A mouse partially chewed through and exposed the copper wiring on the red and green wires. They are all still joined and seemingly intact, but I suspect a small part of the twisted coil was chewed through.

The furnace stopped blowing hot air and the thermostat displays a permanent -AC sign to the right of the clock display on the LED, but the furnace fan is working and its blowing cold air out at the same volume just fine. I've had to unplug the furnace because the thermostat no longer responds to it or turns it off. When I attempt to replug in the power cable, the heating unit automatically turns on and works, blowing out hot air for 10 seconds, then the heat turns off and continues to blow cold air from the fan. I have to unplug it from the wall at this point.

The red light on the lower panel blinks 5 times quickly, then pauses and blinks 5 times again repeating itself until I unplug it.

I have opened the panels and thoroughly checked out all of the wiring, nothing else has been chewed or accessed, just that wire described above that is exposed on the outside.

I seperated the exposed wires and taped them individually in that section and i also replaced the batteries in the thermostat. When I plug the unit back in the wall, same results. Would resetting the unit via a reset switch or resetting the thermostat in some other fashion fix the issue?

If this is something I can fix I would greatly appreciate your help, I do not have any wiring experience. I would like to save money and do it myself.
 

Last edited by Frozenpopsicle; 12-18-12 at 10:17 AM.
Sponsored Links
  #2  
Old 12-18-12, 10:03 AM
Trying2Help's Avatar
Member
Join Date: May 2001
Location: USA
Posts: 715
Sounds like you already know what the problem is, you just need to correct it. The four wires coming out of the unit and going to the t-stat are control wires. If a mouse chewed through the insulation, they are most likely touching each other in that area.
Unplug the heater, inspect these wires and seperate them, so they do not touch each other or any thing else.
Turn the system back on and see if it works properly. If it does, that was the problem and you just neet to repair the affected area, either replace the wiring or tape the indiviual wires so they do not touch.
If it doesn't work, I would suspect you have some more wires chewed up somewhere...look again. Or you could just replace the entire length of wire going from the t-stat to the heater, just connect them the same way they are presently connected (color wise).
 
  #3  
Old 12-18-12, 10:20 AM
Member
Thread Starter
Join Date: Dec 2012
Location: usa
Posts: 5
Thanks, I separated them in that exposed section and taped them so they do not make contact with each other. The t-stat still displays "-AC" and produces the same issue. If the mouse partially chewed through the coil and its somehow been "weakened" would it help if i cut the wires and re-twisted them together? Is that a safe alternative
 
  #4  
Old 12-18-12, 11:01 AM
Trying2Help's Avatar
Member
Join Date: May 2001
Location: USA
Posts: 715
Check this manual: http://johnstonesupply9.com/TechDocs...E%20MANUAL.pdf

Look at page 82 for your 5 flash error, page 84 for the sequence of events on heating. I will assume your unit is stopping at step 3.
Been awhile since I messed with these units, but in order for the pilot to lite, step three has to occur.
Inside your unit, there will be a diaphram with a rubber tube connected to it. Make sure this tube didn't also get chewed. You should be able to blow/suck on it and hear the switch click.
 
  #5  
Old 12-18-12, 12:30 PM
Member
Thread Starter
Join Date: Dec 2012
Location: usa
Posts: 5
Thanks for the manual, i'll look into that. However is the Thermostat "-AC" code a problem in itself? I do recall i pulled the face plate off in frustration when I first realized it was blowing cold air. I had set the switch to off and the fan was still runinng after what seemed to be several minutes. I yanked it out and since then it has been reading -AC. Took out batteries, no change when plugged back in. Here is a picture of it below. Is there a button sequence I can press to reset this?



 

Last edited by Frozenpopsicle; 12-18-12 at 12:57 PM.
  #6  
Old 12-18-12, 02:59 PM
Member
Thread Starter
Join Date: Dec 2012
Location: usa
Posts: 5
Ok heres an update and where I am stuck so far. My issue is the Rollout limit circuit is remaining open.

Checked the tube to the diaphram, it was in perfect condition, clicked when suction applied.

I opened the burner compartment and there was mouse droppings in there with pieces of insulation forming a makeshift bedding on the top layer of the compartment. Cleaned out all that junk and checked all internal wires, nothing chewed. I thought I smelled bbq the last time it was working, I'm lucky there was no fire.

On page 130-131 linked above section s-7 checking flame roll out and resetting control it states:

"The servicer should reset the ignition control by opening and
closing the thermostat circuit. Then look for the ignitor glowing
which indicates there is power to the ignition control.
Measure the voltage between each side of the rollout control
and ground while the ignition control tries to power the gas
valve.
"

What does opening and closing the t-stat circuit exactly mean, do i have to unscrew the wires from the thermostat, or just turn the switch on and off while the unit is plugged in the wall? Ive been poking around with it unplugged so far.
 
  #7  
Old 12-18-12, 07:09 PM
Member
Thread Starter
Join Date: Dec 2012
Location: usa
Posts: 5
Final update. I fixed it.

After cleaning out the flame compartment, located every small red button and depressed it. One of them clicked. The -AC code on the t-stat immediately went away after replugging it in and everything is working.

Thank you, the manual was very helpful.
 
  #8  
Old 12-19-12, 10:35 AM
Trying2Help's Avatar
Member
Join Date: May 2001
Location: USA
Posts: 715
Good deal!!!! I got side tracked with my own life issues, so was unable to respond to you in a timely manner. Plus it was getting difficult for me to understand all the issues without actually be able to "see" the furnace and t-stat. Was afraid it was going to be something simple that "we" would over look, because of internet troubleshooting.

Anyhow, glad you were able to get it going and all is well. Save the manual!!! Have a very Merry and warm Christmas!!!
 
  #9  
Old 12-19-12, 02:32 PM
SeattlePioneer's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jul 2007
Location: Seattle, Wa
Posts: 5,503
You probably did not fix the problem. You reset a safety limit switch, but the problem that caused it to trip is probably still there, will likely recur and can be a safety issue.


Do you know WHICH safety you reset? If so, describe where it is located.
 
  #10  
Old 12-19-12, 10:30 PM
Trying2Help's Avatar
Member
Join Date: May 2001
Location: USA
Posts: 715
Looking up the part number on your t-stat, found this:
https://customer.honeywell.com/resou...0s/68-0056.pdf

Look at page 32. -AC displayed in the room temp location is an indication t-stat is not receiving AC power.

I will assume the red button was a circuit breaker that you reset when you pushed it and allowed the 24V to be applied back to the t-stat.
However, like SeattlePioneer said, you may want to double check what you reset and determine if other actions need to be taken.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes