LatentCond
10-01-2011, 10:43 AM
Went to a call Saturday and was wondering you guys opinions and or suggestions on the solution. When I arrived I noticed 1. No codes flashing on the board, 2. Hot surface ignitor not operating, 3. gas valve not opening. Owner had an infinity T-Stat, checked codes stored and it showed 3 stage pressure switch fault. Checked all pressure switches by drawing a little air thru them and they all clicked, except the pressure switch labeled *condensate*. It had a small orifice inserted and was labeled condensate and was last in series. When I removed the orifice and draw on it, it would then click and operate. I removed the orifice and explained to the customer that their intake air PVC pipe may not be sized large enough to draw enough air to create the proper suction on the last pressure switch. I removed the orifice and the furnace fired normal. So my question is was that a proper diagnosis and why is their an orifice in that pressure switch?