Hi,
I’m the [proud?] owner of a Bryant Plus 80 furnace (315AAV036070AAJA). I’ve recently had some issues with weak heating in the house.
I had someone come take a look - I am handy (mostly vehicles) but thought I ought to just pay someone to save time. The technician showed me that it was throwing a 31 (high pressure switch not opening or reopening). He said they’d have to replace the inducer motor and probably the pressure switch itself in case. I said I’d do it myself-they wanted $1800 and the parts were only $400.
I went ahead and swapped the new ones in. The system still had the same issue (same code). I started doing some reading of my own, and saw that it could be due to a flow restriction (either supply, registers or even something in the exhaust flue). I pulled off the flue output on the unit, went on the roof, and use a leaf blower to push everything out onto a bag. Nothing there aside from some ash. I opened all the vents in the house, and also tried running it without the EAC (filter) for a bit - no dice. Doesn’t seem like it’s an air supply issue.
So, I dug deeper. I cleaned out the draft/vacuum “source” port that operates the pressure switches - not clogged. I checked the switch itself while the unit was running. Lo and behold, it works fine (continuity b/w its terminals when the system switches to high). What seems odd, though, is that the voltage drop across the switch is only 1.8V (should be 24). The drop across the low pressure switch is normal (27V).
And that’s where I am now. I made sure the wires don’t have any breaks or shorts from the switch to the control board. I’m not sure where to go from here - fire the parts cannon and get a control board? Or is there something else I can do to confirm my guess?
Any and all help is greatly appreciated. Merry Christmas!
Michael
I’m the [proud?] owner of a Bryant Plus 80 furnace (315AAV036070AAJA). I’ve recently had some issues with weak heating in the house.
I had someone come take a look - I am handy (mostly vehicles) but thought I ought to just pay someone to save time. The technician showed me that it was throwing a 31 (high pressure switch not opening or reopening). He said they’d have to replace the inducer motor and probably the pressure switch itself in case. I said I’d do it myself-they wanted $1800 and the parts were only $400.
I went ahead and swapped the new ones in. The system still had the same issue (same code). I started doing some reading of my own, and saw that it could be due to a flow restriction (either supply, registers or even something in the exhaust flue). I pulled off the flue output on the unit, went on the roof, and use a leaf blower to push everything out onto a bag. Nothing there aside from some ash. I opened all the vents in the house, and also tried running it without the EAC (filter) for a bit - no dice. Doesn’t seem like it’s an air supply issue.
So, I dug deeper. I cleaned out the draft/vacuum “source” port that operates the pressure switches - not clogged. I checked the switch itself while the unit was running. Lo and behold, it works fine (continuity b/w its terminals when the system switches to high). What seems odd, though, is that the voltage drop across the switch is only 1.8V (should be 24). The drop across the low pressure switch is normal (27V).
And that’s where I am now. I made sure the wires don’t have any breaks or shorts from the switch to the control board. I’m not sure where to go from here - fire the parts cannon and get a control board? Or is there something else I can do to confirm my guess?
Any and all help is greatly appreciated. Merry Christmas!
Michael