HVACopediaRheem · Furnace
55 Pressure switch stuck closed
What the control is telling you
802P and RGPE/RGLE: the high-fire pressure switch (HPC) is closed when it should be open. R95P (single pressure switch): pressure switch stuck closed when it should be open. Furnace will not start a heat cycle.
Applies to: 802P/80MDP (802PA050-150); R95P (R95PA040-115); RGPE/RGLE 2-stage 80+
Likely causes
- Switch contacts welded/stuck
- Shorted or miswired wiring
- Water in switch or hose
Test and repair steps
- With the inducer off, check the pressure switch - must be open.
- Check wiring for shorts.
- Check switch and hose for water or moisture.
- Replace the switch if stuck closed; check the IFC only if wiring and switch are good.
Settings for these units
- Clearance to combustibles (all models) · R95P
- Filter sizes as shipped, upflow (Table 19) · RGPE/RGLE
- Reduced clearance to combustibles, upflow/horizontal (Fig. 4) · Rheem/Ruud 802P / 80MDP 80% two-stage furnace (UT 1028-928 IFC)
- Reduced clearance to combustibles (Fig. 3 and 4) · RGPE/RGLE
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Source: 802P: 92-24161-146-02, Diagnostics and Fault Codes table, p.40, 51; R95P: Diagnostics and Fault Codes table, p.87 (PDF p.91); RGPE/RGLE: Table 16 p.49 / Table 20. Summarized in our own words; check the original manual for your model.
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For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.