Furnace Issue continued from Spring

[The Weekenders]

This past spring, my furnace had issues where the blower would come on but no igniter. Back then, I would pull the outside cover off and wiggle the wires and ignited kicked in. Would work for awhile then same old problem. Tested reset switch and that was fine. Replaced wire for igniter and still hit and miss. By then the spring warmed up and I forgot about it. Well fast forward to our first Freeze warning of the season and same old problems. I own a radio station and my midday guy is an engineer who loves to solve techie problems. He traced it to two quick connect connecters that apparently were not making good contact. A few snips and some wire nuts and it seems to be working good. Of course I have been down this road before but time will tell. We are dry camping this weekend at our old farmstead and we'll see if it's entirely fixed. Luckily temps in NoDak will be back to low 70s this weekend and low 50's for lows so no big deal if we go back to square one. I also had the issue with the kitchen sink facuet with no pressure and fixed that thanks to you the great members with the suggestions given. Also this evening, my toilet was letting water seep from the bowl back into the tank (something ongoing all summer). The lid was not closing properly. Ended up pulling off the ceramic bowl and lubing it. Reattached and its holding water perfectly. 3 years old and all these little things. But then again we pretty much live in it from April-October 5-6 days a week with a nite at sticks and brick for the DW to do the laundry. Rant over!

[wingerphil]

Several of us have had the same issue with the little "button" type connectors on the furnace. I replaced mine about 2 years ago with some decent crimp type 12v connectors and no problems since. Sounds like you have gotten your issue resolved as well.

[The Weekenders]

No such luck this morning, back to the old blower kicks on and no igniter. Opened the cover, wiggled some wires and away it goes. Another challenge for my engineer.

[wingerphil]

one other issue I had with mine.
When it does this again tap on the blower case with the handle of screw driver (or similier). My sail switch was bad, it's mounted on the inside of the blower casing, and tapping it would close the switch and the furnace would lite up. The sail switch has a "paddle" on it and senses the fan is blowing enough air to allow for ignition. The fan will start and you can hear the igniter click on and try to light 3 times before the furnace goes into "lock out" mode. There should be a flashing red light on the circuit board that will flash a code to help the technician diagnose the problem when it locks out. To reset the the furnace just cycle the switch mounted near the blower casing and it will go through the process again.
The sail switch cost under $10.00 at the RV dealer and I changed it myself, wasn't too hard once I figured out the problem.
Good luck

Phil

[Ozz]

My money is on the sail switch, if it doesn't prove, it won't try ignition. Very hard to troubleshoot remotely, could be tons of things, but I would start there. Phil's problem with the sail switch is close to yours isn't it?

[The Weekenders]

Difference between mine and Phils is that he heard the igniter click on 3 times before shutting down whereas I dont hear the igntiter click on at all. Good point on the sail switch. My engineer wants to replace all the wires.

[Ozz]

Have him jump the sail switch first...if the blower is blowing good... and if that does it, you have your culprit.
Many times when I repaired heat on rooftop units especially, just un-plugging and plugging in the wires cleaned the contacts enough to get power going. All these control systems are 12 volts, it doesn't take much to halt current flow.
Good luck with it.

[pappy65]

I had trouble with mine all summer in Colorado. It was easy to prove sail switch was OK by reading 12V on output lead (red) to gas valve. I could also hear ignitor trying to light burner 3 times then lockout furnace. Mine is either a wire connection at the gas valve, either the ground or 12V lead. Could also be the gas valve solenoid not operating. Mine has one month left on warranty, so I will probably take it in just to get documented. I could pull on leads at gas valve or tap on solenoid at gas valve and it would start working. I could read 12V to housing ground when it was in failed state. I suspect either the ground leads at valve or bad solenoid. Gas valve has 2 solenoids.

[Ozz]

Yep, one is pilot, one main burner

[The Weekenders]

My engineer took the circuit board off and resoldered all the ends on it and ran it on the meter (which showed everything on the board is fine) but still same old problems. Per a suggestion here, I tapped on the blower casing to see if it was the sail switch and the igniter did not kick in. Wiggled on the wires and igniter kicks in. Overnite, it would not kick on, blower then it shuts off. About 2 am it worked normally for several hours. Around 6 am, same crap again. When it the igniter does not kick in, the red light blinks once. But a simple wiggle of the wires and it works fine. Next week, me and my engineer plan replacing all the wires and see where that gets us. I have previously pulled every wire off, inspected the connectors and sprayed with contact cleaner. Very frustrating.

[exav8tr]

Unless you are having an intermittent electrical problem with the gas valve solenoids, I doubt it is the valve. Mine quit completely several years ago and a tech said it was the valve. He replaced it and no problems since. I'm suspecting you may have an intermittent problem in the mother board. If you have replaced all the wires and you can get it to work by tugging on the wires, perhaps you have a broken wire inside the insulation or the MB is going bad. The problem with electrical issues is they never seem to show up when it is at the dealer. On my '05 Chevy TV the drivers side ac vent would start blowing hot air, when it should have been cold. Dearler tried three seperate times to duplicate the problem and never could. The last time I picked it up I drove about ten minutes and it started doing it again, I turned around and drove directly back to the dealer and had him place his hand over the vents to prove something was wrong. GM ended up replacing the entire AC module and that cured the problem.

[Ozz]

FYI, when a guy 'jiggles' the wire, it breaks contact, then makes contact, it resets the control system.
Jump the sail switch and see if that makes it fire.

[The Weekenders]

For those of keeping score on my furnace misadventures, early last evening I give one last "tug" on the wires and it worked perfectly the entire evening and through the nite. To me it is a wiring issue not a sail switch. What do you think?

[Ozz]

Sounds like it. Like i said, it is very hard to troubleshoot over the internet.
I hope that solves the riddle for you, a guy has to have heat

[08UltraRider]

Intermittent electrical issues have driven many to drinking.

If this helps… The day after I brought my new 2012 Montana home the furnace did pretty much the same thing… Keystone put me through to Atwood who had me wiggle a couple of wires on the circuit board and it started working again… sometimes!

Keystone authorized a mobile repairman to check the circuit board where he tested and it worked for him…. Twice…. Replaced the circuit board and it’s worked flawlessly since… He said a he's seen a defective board work intermittently before... Often enough he had a new one with him.

I hope this helps.

[The Weekenders]

Thanks Tim!! A very frustrating situation. Glad you got yours resolved! My furnace has worked properly the past 2 nites (A real record for mine). We are going to replace all the wires this week.

[pappy65]

Please keep us posted. I still plan to get with the dealer on mine, but being intermittent problem, I don't have much confidence it will get fixed on first try. I have a good schematic I downloaded and have proved when mine fails the sail switch is OK. I get 12V at the gas valve, and I hear ignitor attempting to light. The dual solenoid valve operates both solenoids on one red 12V lead,goes from circuit board to one solenoid and jumpers to the other, so I don't think it is the valve. I suspect the ground to the valve. It is run to the valve body and jumpered to each solenoid winding.After reading Tim's, could be a flaky circuit board.

[Ozz]

quote:Originally posted by pappy65

Please keep us posted. I still plan to get with the dealer on mine, but being intermittent problem, I don't have much confidence it will get fixed on first try. I have a good schematic I downloaded and have proved when mine fails the sail switch is OK. I get 12V at the gas valve, and I hear ignitor attempting to light. The dual solenoid valve operates both solenoids on one red 12V lead,goes from circuit board to one solenoid and jumpers to the other, so I don't think it is the valve. I suspect the ground to the valve. It is run to the valve body and jumpered to each solenoid winding.After reading Tim's, could be a flaky circuit board.

Could easily be a dirty flame rod, clean it and try it then.

[The Weekenders]

We finally got around to look at the furnace after a few days of el-crapo weather and my engineer ran the meter on the sail switch and sure enought that's what it is. How hard is it to get at? What way did you folks do it?

[wingerphil]

take off the outer metal access panel, the blower case is a large oval shaped black plastic container. There are 4 screws that hold the case together, 2 at top, 2 at the bottom. Remove the screws and seperate the case, The sail switch is mounted inside the 1/2 of the case you just removed. Replace the sail switch with new and reverse the process and your done.

I remember the hardest part being lining up the 2 parts of the case again, make sure all is lined up properly or the fan will hit, it is a little tricky but if I can do it, anyone can!

Good Luck and glad you found the problem

Phil