Bryant Plus 90 Problems

______________________________________________________________________ I have a Bryant Plus 90 gas furnace thats 13-14 years old. Recently, it has stopped working about twice a day (once during the night, once while I’m away at work). I’ve usually been able to get it working again by powering it off and back on anywhere from 1 to 5 times. Now, I’m not the handyman type, so many of these terms I hear being thrown around on these forums are foreign to me. I’ve had service technicians over twice. I explained to service techs that I’m kinda strapped for money and would like to try to get through this winter as inexpensively as possible. Replacing my furnace would be a last option. The first technician theorized I had a trouble with air intake and perhaps a pressure switch problem but didn’t have the part. He pulled a plastic cap off what looks like a fan/blower to improve air intake. My problem persisted. The second technician replaced the pressure switch, clean the flame sensor and resecured the intake pipe at a spot where a bracket had broken. At first, I thought this fixed the problem, but now I’m back to the same problem where it stops working twice a day. Just now, I had to turn off/on my unit 6 times before it worked. After unit stops working, I always get error code 21. Here are the symptoms: 1. After powering on, blower runs for about 90 seconds 2. Then I hear a different unit kick on and I hear a trickling sound. I assume this is gas flow. 3. After about 10-15 second I see a coil start to glow 4. In another few seconds I hear a click 5. Sometimes no flame, sometimes flame for moment and then it goes out, and sometimes (usually after 3-5 off/on tries) the flame stays on at which time, my home will warm up. 6. At some point in time over the next 8-10 hours the unit stops working. 7. Always error code 21. Is there anything a non-handyman can do to diagnose/remedy this problem? I know I’ll probably have to call a technician again, but I’d like to be prepared with some information so they just don’t replace another part hoping that its gonna work. With service charge and parts this approach is getting expensive. If possible, I’d like to get it fixed right the next time. Thanks for you time, Bob Bob Riley Replies: hvac42long “Re(1):Bryant Plus 90 Problems” , posted Tue 20 Feb 13:06 ______________________________________________________________________ Sometimes you have to bite the bullet. Considering the age of the unit and your lack of knowledge, and the fact that you have little faith in the service “techs” abilities it would probably be more cost effective to replace the furnace. By the time you pay these guys to change a bunch of parts, and eventually maybe get the right one you should replace the furnace. mgussler614 “Re(1):Bryant Plus 90 Problems” , posted Mon 19 Feb 18:53 ______________________________________________________________________ i have the trouble shooting book for a bryant/carrier series furnace the code 21 talk about the pl5 connctor on the board either loose or going bad shorting need to check the circuit board to make sure the connection is tight to the control board if it is make sure the furnace is set to the right air flow. then if that doen’t work then the solder joints on the board are going bad and you will probaily need a new board is that furnace a viable speed 2 stage or a single stage furnace? please send email guz 1 bgriley13 “Re(2):Bryant Plus 90 Problems” , posted Mon 19 Feb 20:51 ______________________________________________________________________ Guz: Thanks for the reply. Do you have any idea where I would find the pl5 connector? I tried to figure out the schematic on the inside cover and it seems to indicate that two wires, one black, one white go from pl2 to pl5 on the circuit board. I can find pl2, but I can’t find pl5. There is a two piece white plastic thing that snaps together into which the wires from pl2 go, but its not on the circuit board like the schematic indicates. Two “cloth-type” wires come out the other end and go into burner chamber. I made sure that was securely snapped together. Would that be pl5 connector? Regardless, didn’t seem to help problem. I still had to go through the off/on cycle 4-5 times before I got a flame and it held. How do I set air flow? Bob Riley Antonetz “Re(1):Bryant Plus 90 Problems” , posted Mon 19 Feb 10:25 ______________________________________________________________________ the trickeling sound is not gas flow, gas comes on just after glow bar lights, check gas valves manifold pressure, insuring valve & pressures are proper, 3.5″ or it may be the combustion blower motor housing could have water in it. pull drain and insure they are not restricked and that the supply piping is properly pitch twards the furnace, & insure there is no moisture in the pressure switch tube.let me know if this helps. R.P.Antonetz bgriley13 “Re(2):Bryant Plus 90 Problems” , posted Mon 19 Feb 13:25 ______________________________________________________________________ Antonetz: Thanks for the reply, but I’m not the handyman type, so I don’t know what a lot of those devices are that you’re mentioning. Or are you providing me with this advice to pass onto service tech? I did check to see if the drain was obstructed and it appears to be ok. Plus supply piping appears to be pitched towards the furnace. I do know what the pressure switch is. Is it ok for me to pull off hoses and check for water? I’ll powere off unit first. The other suggestions I can’t handle as I don’t know what the mentioned components are. Does the fact that I usually have to turn machine off/on several times before it works point to anything? Over the last couple weeks, seems like I have to go through more iterations of off/on until it works. I just want to avoid the call the service tech/service charge/guess at another part cycle if possible. Thanks. Bob Riley