Rheem / Ruud · Furnace error code
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Get lifetime accessOnCall Tech is a reference tool for trained technicians and can make mistakes. Always disconnect power and confirm with the manufacturer's documentation before you work.
Guide · FurnaceThe pressure switch proves the inducer is moving combustion gases. It stays open when the vent/intake is blocked, the hose or port is plugged, the condensate trap backs up, or the inducer is weak.
Component test · FurnaceThe pressure switch proves the inducer is pulling enough draft before ignition is allowed. Test it with a meter (24 V across it) and a manometer against the set point printed on the switch. Gas valve, gas pressure and burner work are not covered: refer those to a licensed gas technician.
Guide · FurnaceStart with the board LED code, then work the call path: thermostat, 24 V, safeties, inducer, ignition, flame proving. Most no-heat calls end at a filter, a flame sensor, a pressure switch issue or gas being off.