[gandalfthewhite]

Hello. I have a weather king gas furnace
The model number is:
Rcba-245-7gg17xi
Serial number is:
t490400752
It is less than three years old. He had a problem where the heat wouldn't turn on last week. But it suddenly decided to work. But today we have the same problem again. I figured out that both times was because we switched the unit to cool. But it doesn't seem to want to switch back. The blower starts up when you call for heat, but the glow plug doesn't heat up so the furnace doesn't ignite. I know they work because it just did this samething the other day, and eventually it turned on. So I fugre its having problems switching. Any ideas? Thanks for the help.:confused:

[gandalfthewhite]

OKay I finally found the manual for this furnace. The error light blinks twice which means Pressure switch is open. I assume it means it needs to be closed. How can I do that?

[EPMiller]

I believe the pressure switch indicated by the fault code is a proving switch for the draft. It is a diaphragm unit, and if the fault is electrical, you will be replacing it as an assembly. There is a small possibility that it is a plugged or crimped pressure tube, in which case you can just repair that part. Car vacuum line or gas line (correct diameter of course) will work if heat is not an issue. The schematic of the unit will help you locate it. Then you have to find a supplier to get the correct part.

[gandalfthewhite]

AHHH HAAAA I figured it out. The hole for the hose running from the pressure switch was blockd up. I cleaned it out and bingo working furnace.