Parent's Bryant (Carrier) gas furnace dead tonight. I took a look at it, and found that the controller was flashing a code 32, which tranlates to low induction pressure.
The induction fan was not coming on at all, so the error code made sense from that standpoint. But why is the fan not coming on? The way the controller is mounted, in a sheet-metal shroud, I could only see the front part where the LED code flasher was. I removed the two screws holding the shroud and lowered it out of the cabinet. The problem was then visible: a burned-out relay on the board. It had apparently gotten quite hot, as the plastic case of the relay was deformed and the board was black around where it was attached. There was also the distinctive burnt-resin smell from the scorched circuit board substrate. So we're going to need a new controller board, but why did this happen? Those controllers are expensive so I don't want to have the same problem with the replacement. Can a relay just go bad and burn up like that? I would think the more likely explanation is that it became overloaded due to a problem with the induction blower motor. However the motor turns easily, doesn't seem to have a bad bearing or anything that would obviously cause a heavy current draw. Ideas? Allan -- 1983 300D 1979 300SD _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
