TrailManor Owner's Forum  

Go Back   TrailManor Owner's Forum > TrailManor Technical Discussions > Appliances
Register FAQ Members List Calendar Mark Forums Read

Reply
 
Thread Tools Display Modes
Old Today, 05:13 PM   #41
Bill
Site Team
 
Bill's Avatar
 
Join Date: Feb 2003
Location: The mountains of Scottsdale, AZ, and the beaches of Maine
Posts: 10,252
Default

The limit switch (Item 17 in the diagram referenced in post #29 above) is supposed to be closed normally, and opens only in an overheat situation. A quick check is to remove both wires from it, and measure its resistance. The resistance should be very close to zero. If it is very high, it is stuck opened. In this case, give it a couple short sharp bops with a screwdriver handle and see if it closes. That is known as BILL'S UNIVERSAL FIX.

If shorting across it didn't work, that means there are multiple failures. While possible, this seems unlikely, so while you have it shorted, re-check everything carefully, using all the advice about wait-timing above.

I see the empty red connector you mentioned - good eye. I think I see a blue wire, but a better photo of it would help. Are you thinking that the blue wire should be coming out of the empty red connector? Is the end of the blue wire actually not connected to anything, as if it were broken off? Is the end of it stripped, leaving a half inch of bare copper showing, as if it had pulled out of the red connector? Is it long enough to reach the red connector? Bear on mind that an empty crimp connector may be what is intended by the mfr, and does not necessarily indicate a problem. In this case, it could be part of the thermistor circuit that is not used in this furnace.

Bill
__________________
2020 2720QS (aka 2720SL)
2014 Ford F-150 4WD 5.0L
Bill's Tech Stuff album
Bill is offline   Reply With Quote
Old Today, 06:00 PM   #42
Rob Culver
Senior Member
 
Join Date: Nov 2023
Posts: 106
Default

Quote:
Originally Posted by Bill View Post
I think this is normal. If I am reading the manual and your comment correctly, the wire you checked "at the ignitor" is the brown wire that goes to the gas valve. Gas valves operate on very low voltage - they don't want anything high enough to create a spark inside the valve. On a heater with a pilot light (which this one does not have), there is a thermistor that sits in the pilot flame, and generates about 0.25 VDC when the pilot flame is good. This low voltage is what opens the gas valve. DO NOT apply 12 VDC here, or you will burn out the valve and quite possibly the module board.

Bill
Hi Bill,
Here's a picture of the spot where I measured .25 volts, Where the brown/red wire connects to the terminal. Are you saying that this is the spot which should only have .25 volts? I thought this spot is what supplies the igniter and it needs over 12 volts.
Attached Thumbnails
Click image for larger version

Name:	20250209_154918.jpg
Views:	3
Size:	1.45 MB
ID:	23801  
__________________
2023 2720QS
2022 Nissan Frontier SV
Rob Culver is online now   Reply With Quote
Old Today, 07:45 PM   #43
Rob Culver
Senior Member
 
Join Date: Nov 2023
Posts: 106
Default

Quote:
Originally Posted by Rob Culver View Post
Hi Bill,
Here's a picture of the spot where I measured .25 volts, Where the brown/red wire connects to the terminal. Are you saying that this is the spot which should only have .25 volts? I thought this spot is what supplies the igniter and it needs over 12 volts.
Upon further research, I'm pretty sure this is the wire that connects to the igniter. I'm reading now that this spot can go to 1,000's of volts in order to generate a spark, so it probably wasn't even prudent to try and measure it with my multimeter.
__________________
2023 2720QS
2022 Nissan Frontier SV
Rob Culver is online now   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 11 (3 members and 8 guests)
Rob Culver, rtcassel, Wavery
Thread Tools
Display Modes

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Issue with furnace - smell un-burnt propane tentcamper Appliances 9 10-22-2014 02:11 PM
Can't ignite water heater using propane rbauer Plumbing 12 09-09-2012 09:04 PM
Improper furnace install in 2720sd. Throttled. kokilo Feedback to TrailManor 4 02-09-2012 11:23 AM
Propane furnace, new consumption record set, maybe PopBeavers Appliances 4 04-16-2006 02:51 PM


All times are GMT -6. The time now is 11:58 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
Copyright 2022 Trailmanor Owners Page.