Rheem · Furnace

26 Line and neutral reversed

High severity Rheem/Ruud 802P / 80MDP 80% two-stage furnace (UT 1028-928 IFC)R95PRGPE/RGLE

What the control is telling you

Supply polarity is reversed. The control may not sense flame when L1 and neutral are swapped; RGPE/RGLE will not operate without correct polarity and also alerts the homeowner (Call For Service).

Applies to: 802P/80MDP (802PA050-150); R95P (R95PA040-115); RGPE/RGLE 2-stage 80+

Likely causes

L1 (hot) and neutral swapped at the junction box or IFC
Poor or missing ground

Test and repair steps

Warning: Turn off power before moving line-voltage wires.
Measure L1 to ground (about line voltage) and neutral to ground (near 0 V).
Swap hot and neutral so L1 goes to the hot terminal per the wiring diagram.
Check ground continuity to the IFC and unit.
RGPE/RGLE with door switch held in, 120 VAC terminal to ground and to neutral should read nominal 115 V (acceptable 105-120 VAC); have an electrician fix an inconsistent supply.
Restore power and confirm the code clears.

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.28, 40; R95P: Diagnostics and Fault Codes table, p.87 (PDF p.91); RGPE/RGLE: Table 16 p.49 / Table 20; Electrical Checks p.24. Summarized in our own words; check the original manual for your model.

Homeowner looking at this code? See what it means for you and when to call a technician.

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.