Presidential II

[Minnesota]

Model 7680B856
The pilot light is on, but burners wont kick on and blower motor wont kick in. Is there just a simple reset button? Seems to me I recall one in my previous mobile home.

[Lifted79chevy350]

yes I have the same unit. Pull the upper cover off. Turn the black switch on top of the electrical box on the left. The reset button is on the left side of the blower motor. its kinda on the side in the back there are 2 black wires running to it in the center is a red reset button thats the upper limit switch only one i know of.

[Robert]

Are you getting 24vac to the gas valve ?



Thanks,
Robert

[Minnesota]

Thanks for the replies fellas. I just went in there after reading your posts. 1st thing I did was pulled off the panel underneath the on/off switch and made certain all wire nuts were snug. Then I did locate the upper limit switch exactly where you said it was. Except it did not have a reset button. Discouraged, but not defeated, I just took screwdriver with a rubber handle, and stuck the handle end in 1st, gave it a couple taps, still nothing. Then I used a little force and bent each of the two wire connections back and forth just a little bit and woof, those burners lit up like they were saying its about time. And as a thank you, in just a few short minutes it was blowing out nice warm air again.

Now, I think I know what the problem was. Last winter I had pretty much taped shut all but 3 of the 9 heat registers in the house. 1 on the far end of the house was open in the living room, the other 2 were open in the other end of the house in the master bed. I had done this as a quick fix because the ducting was so poor that we couldnt get air to those areas of the house no other way. Well about a month ago, I had hired someone to come in and make my house more efficient. New windows, cleaned out furnace and new filters, and fixed all the ducting. I had totally forgotten about my duct tape job. So the hot air had hardly any where to go. The 3 vents that were open, I could fly a kite over them they were blowing so hard. In fact I had big nasty spiderwebs come up out of these registers. I have since gone through and removed any duct tape I had on. So with that said, Im wondering if that back pressure was too much and caused the furnace to get too warm. Not sure how I got it to work by bending the contacts back and forth unless it got hot to the point where it may have melted? I didnt slide out the blower motor, but there didnt appear to be any type of corrosion. So I think I will just be safe and go purchase a new switch and have it on standby if it happens again.

Also, the lower limit switch had a reset button, but it was not in need of resetting.
I also did not check to see if there was 24V Robert. I left my tools in my truck, and my truck is currently in Wis, and its abouts a 2 hr drive for me.

Thanks again guys, but rest assured, if I have other issues I will be back, if anything just to give an update.

[Minnesota]

i have an older coleman furnace in my home model # DGRT056AUA. I want to be able to control the blower with the thermostat without using the furnace itself to circulate air through the house and would like any help on how to do this. thanks

I wont hijack his thread, but I also would like to do this as well. I had the service guy get rid of the original coleman thermostat and put in a digital one. I only have 2 wires for it, a red and white. I have the option on the t-stat to have fan on constant, circulate, or auto. Id really like to be able to have these options.

[Robert]

Hi,

Can you look at your upper limit and lower limit and give me the numbers on both.

You'll need to run 5 wire t-stat wire from furnace to wall t-stat first.


Then do some disconnecting, rewiring and adding of parts OR buy a 4 wire a/c control box and replace the current 2 wire one you have now.



Thanks,
Robert

[Minnesota]

Cheapest possible route is always the best in my book. When my wife gets home from work this evening, I will take her camera and take a snapshot of what I got under the hood...lol

I wasnt sure which numbers were which so I wrote all of them down.

Upper Limit
L140-2
7680-379
20601L9-46
D9V

Lower Limit
L180F
60T14
9236
206089
2840A319

Cosmetic difference between the 2 were that the lower one has the red reset button, and the numbers were on the mounting side so that I had to take it out and flip it over to read it.

And the top one I inspected closer as I pulled the blower out to get at it anyways. It is in perfect shape. The actual issue was the wire connector being spread apart so it was real lose. I unplugged it and used a pliers and just squeezed them together to make a tight connection. Put it all back together and ran it through another cycle with no issues.

[Robert]

Upper Limit Switch is correct one.

Lower Limit should be #7680-3591 which can be seen and ordered here by paging down:

http://www.mobilehomerepair.com/Order4b.html



Cheapest would be the rewiring and changing parts around. Go here to pay $20 troubleshooting fee:

http://www.mobilehomerepair.com/Order4b.html




Thanks,
Robert