Age of equipment: 2001 is the model year as best as I can tell
Brand: Bryant
Efficiency: Plus 80
Natural gas
Split system, (furnace inside A/C outside)

Thermostat set to heat, inducer runs, no Ignitor glow, I can hear the gas being run then stopped after a few seconds when there is no ignition and it repeats until the furnace locks out. Error code 34 at first and then 14 after lockout.

I replaced the ignitor and the system ran for a day or two and then same thing. Old one looked a bit worn, but no cracks (until I dropped it anyway). It did work for a few days after it was replaced but back to its old tricks soon enough.

I checked the filter, thermostat batteries, vacuumed the furnace a bit to clean out any debris that could be causing an issue, used some steel wool to clean a relatively clean flame sensor, checked board connections to ignitor. Nothing. It does randomly work after being reset a time or two, but eventually will fail.

Put a voltmeter on the board to see what kind of juice I was getting from the ignition connection and see only 40v randomly after cycling the system and holding the door switch. I assume this should be higher around 120v to be correct or am I out of line? I took the board off to see if anything was loose or burnt on the back, but nothing out of the ordinary. Any ideas anyone?

Bryant Plus 80 furnace Model # 395cav024045fjja
Serial # 1701a71294
on the board I see 1012-940-m hk42fz016

buddy of mine who does HVAC told me it was the board, but I'd like a some insight before I make the purchase. Anyone recommend a place I can buy this thing too if it turns out to be this?

Use a volt meter to confirm 120 volts is being applied to the ignitor. If it is, make sure the pins on both sides of the plug are in good shape & tight in the plastic holder.

If you are only getting a reading of 40v, then the board is bad. Do as Grady suggest and make sure all connections when testing for proper voltage (roughly 120v) are good. If all connections check out, your board is indeed in need of replacement. I would check for 120v directly at the board before replacing the board. If you get 120v at the board, the problem lies in the wiring between the board and the glow plug.

Checked the connection on the board directly and its only putting out 40v, but nothing looked physically out the ordinary. If the connection pins are loose or bad can it be replaced, fixed, or jerryrigged somehow? Or is the whole board to blame and if so what part do I order?

No. sorry, there is no repairing a control board. Even when you can't see any physical damage, they still can be bad, and sure sounds like yours is. The fact that you are getting 40v tells me that the board is telling power to go to the igniter like it should, but the board is bad so it isn't giving correct voltage. Check for proper 120v coming into the control board, and if you have that, you most certainly need a complete new control board. Take the model and serial number of the furnace itself to a local hvac shop and have them order you a new control board. Should be all set after that.

Usually, but not always, when you read voltages in the 40-80 volt range the problem is with the neutral. That problem could be on the board or a neutral connection.

If the problem is a neutral connection, what would I check for to verify this or rectify?

Check the voltage to ground rather than across the two terminals. If you get 120 to ground, you have a neutral problem. If you've lost neutal on the board, you will need a new board unless you can find someone to repair it & the likelihood of that is pretty slim.

https://www.askmehelpdesk.com/heatin...04-344829.html

Ran into the same situation as this person, but I am not sure if I wired everything up appropriately. I'd appreciate it if someone could give me a thumbs up. I ended up buying a ICM282A board and wired it today. But I had a COM and PR2 spade leftover that I couldn't easily identify where to put it.

I wired up the two neutrals like he did in the post I linked in the second picture. So, if we are looking at it straight on like this 1 2 3 being the first row and 4 5 6 being the second row. For reference, L2 is 1 and EAC-2 is 4.

I wired the 2 neutrals that came off the harness to 2 and 5. I put the L2 in the 1st position. Com on the 6 position and PR2 on the 3rd spot. The 4th position, EAC-2, is empty and I believe was empty on my original board. Does this seem appropriate? Just a little gun shy to turn it all on till I feel confident in the wiring.

It sounds like it's your PRESSURE SWITCH is sticking or there is a partial block in the hose from the inducer housing.. VERY common. And A lot easier than trying to rewire a board
Pull the two wires from the pressure switch and plug them onto a 3 amp spade type fuse ( auto fuse).. cycle that a few times..
If you have no faults then you found it.. and BEFORE you try that make sure there is'nt a bag or something part blocking the vent cap. Ive worked on D/N carriers for a lot of years that sieries. That's where I would start . If it's the board it requires a Conversion board ( very pricey, around 250 to 300 from a service center.. . REWIRING is a LAST resort..

Quote:

---

Originally Posted by nvdragon1

it sounds like it's your PRESSURE SWITCH is sticking or there is a partial block in the hose from the inducer housing .. VERY common. And ALOT easier than tring to rewire a board
Pull the two wires from the pressure switch and plug them onto a 3 amp spade type fuse ( auto fuse) .. cycle that a few times ..
if you have no faults then you found it .. and BEFORE you try that make sure there is'nt a bag or something part blocking the vent cap. Ive worked on D/N carriers for alot of years that sieries. thats where I would start . if its the board it requires a Conversion board ( very pricey, around 250 to 300 from a service center. ... REWIRING is a LAST resort ..

---

I'll give this a try. So, I will put a auto fuse on the two wires going into the PS to check to see if everything fires up properly? Could I take my ohm meter and check to see if the pressure switch is doing its thing during the call for heat? I'll check that too I suppose. Would this explain why I was getting less than 120v from the board when I check it on my voltage meter?

I still have the replacement board that I ordered. Was this incorrect? Like I said, everything is wired up properly except for a bit of confusion on where exactly the COM and PR2 wire go, but they are only a few spots left where they could go so should I just start it up and see what works?

Am I correct to assume that blowing out the pressure switch hoses could clear an obstruction that also might cause this problem? I'll give it a try tomorrow and report back.

Regarding the vent, this is a condo so I will have a bit more difficulty checking to see for any obstruction on the top of the roof. I'll see what I can muster.

Im sorry, but I don't want to take the chance on wiring of the board without being there firsthand. Hate to fry a board for you. However, I still say the board was the culprit. If the pressure switch was not closing, the board would not be trying to send any voltage at all to the igniter. In your case, the pressure switch must be closing, allowing the board to send voltage to the ingniter, just not enough voltage due to board malfunction (whether it be a neutral issue in the connection or one of the relays etc, stiil a board issue, and replacement is the only real fix.) You can certainly put the old board back in and test the pressure switch doing a continuity or ohm or voltage test, you aren't out anything other than a little time, so it can't hurt.

The replacement board should have come with a wiring diagram to get it all set up. Look it over very closely and when you feel confident that it is correct, start it up and please let us know how things work out.

No worries, I've gone over it a few times but there is some vagueness on where exactly these last two connections go much like the poster in the link I posted or exactly like if you saw the pictures. https://www.askmehelpdesk.com/heatin...04-344829.html I am fairly sure its wired up correctly, I was just seeking playing it safe and seeing if anyone had some light to shed on this vaguery.

Nvdragon. Do the boards on those carriers put out 40v to igniter all the time even with the pressure switch open? I don't get to work on many carriers, but I assume the boards work somewhat the same as boards on most other brands? I may learn something here, and Im always up for that. Either way, Demian has already installed the new board and just has a question about a couple of wires. Any way you could confirm his wiring with the conversion board?

Found this guys quote on the internet regarding this issue:
Originally Posted by dsw40291 View Post
I could only find the ICM board locally and have it all done except for two wires. The COM wire does not fit on the new ICM board and I can't find the place for the PR2. Any suggestions??
L2, PR2, and Com are all the same point electrically. Also called the "Neutral" which is the White wire in the single phase AC service. They should all be close to the L2 which is near the LED.

I believe all six terminals in that area of the board are neutrals, so as long as you have those three wires hooked to any one of those six, you should be good to go. Are all three of the wires white? If so, fire it up and let us know how things work out. L2 is a neutral, com is a neutral, and PR2(primary 2) is a neutral. Should be no concerns here. Does your new board have a 3 amp fuse? If so, the worst that can happen is you burn that fuse. Is the com from the blower?

Quote:

---

Originally Posted by mygirlsdad77

I believe all six terminals in that area of the board are neutrals, so as long as you have those three wires hooked to any one of those six, you should be good to go. Are all three of the wires white? If so, fire it up and let us know how things work out. L2 is a neutral, com is a neutral, and PR2(primary 2) is a neutral. Should be no concerns here.

---

I read that and yes they are all white and in the neutral group, but I was just covering my butt in case I got ahead of myself. Great feeling more confident now.

Okay, fire that pig up and let us know what happens. Standing by.

Sorry will have to wait till morning, I am out of town until tomorrow, but I'll post right away whatever the result.

Ugh, I was hoping you would be doing the happy dance tonight. Oh well, tomorrow it is. I won't be able to check in till after work, but I have my fingers crossed. I really think you have this thing licked. Take care.