Rheem Error Code 45: Low pressure switch open – inducer high speed (Furnace)

Updated October 13, 2026 · by Aurora Star Tech Inc.

Rheem error code 45 on a furnace means: Low pressure switch open - inducer high speed. It is also called Rheem diagnostic code 45.

High severityFurnaceRheem/Ruud 802P / 80MDP 80% two-stage furnace (UT 1028-928 IFC) · RGPE/RGLE

Homeowner? What Rheem code 45 means for you

Call a technician Your furnace is reporting: Low pressure switch open - inducer high speed. The furnace has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.

Safe things you can check yourself

Check the thermostat: right mode (Heat or Cool), set a few degrees past room temperature, and fresh batteries if it uses them.
Make sure the unit has power: its on/off switch (often looks like a light switch near the unit) is ON and the breaker in the electrical panel is not tripped.
Make sure the furnace front door or panel is closed properly; many furnaces will not run with the door switch open.
Look at the air filter. If it is grey and clogged, replace it; a blocked filter causes many shutdowns.
Outside, make sure the intake and exhaust pipes or vent cap are not blocked by snow, ice, leaves or a nest.
Check that the gas valve next to the furnace is open (handle in line with the pipe). Do not force it.
Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.

Call (647) 657-2977 Book a service call

Licensed technicians serving Vaughan, Toronto and the GTA.

What does Rheem error code 45 mean?

Low pressure switch did not close (or opened) with the inducer on high speed. If not closed after 60 seconds of inducer run, a 5-minute soft lockout follows. RGPE/RGLE: Table 16 text LPC OPEN; meaning per 802P - verify on unit. Not stored back-to-back in the RGPE fault buffer.

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

Common causes of Rheem code 45

Inducer not running or weak
Loose, leaking, kinked or water-filled pressure hose
Blocked vent, improper vent size/length or too many elbows

A technician checks these and 3 other possible causes on site before replacing any part.

Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.

Rheem models that use code 45

R802PA050314MSA R802PA075417MSA R802PA100521MSA R802PA125524MSA R802PA150524MSA RGLE-05(-)BMKR RGLE-07(-)AMKR RGLE-07(-)BRQR RGLE-10(-)BRMR RGLE-12(-)ARMR RGPE-05(-)BMKR RGPE-07(-)AMKR RGPE-07(-)BRQR RGPE-10(-)BRMR RGPE-12(-)ARMR

Other Rheem Furnace codes

Code	Meaning
20	Twinning fault
22	Main limit open
23	HALC limit open (HALC LIMIT OPEN)
26	Line and neutral reversed
33	Rollout switch (MRLC) open
44	Low pressure switch closed (stuck)
46	Low pressure switch open - inducer low speed
55	Pressure switch stuck closed
57	Pressure switch stuck open
58	Water sense circuit open
59	Water sensed / blocked drain
60	Blower fault - running (BLWR FLT-RUN)

All Rheem Furnace error codes →

Rheem code 45: homeowner questions

What does Rheem code 45 mean?

Low pressure switch open - inducer high speed. Low pressure switch did not close (or opened) with the inducer on high speed. If not closed after 60 seconds of inducer run, a 5-minute soft lockout follows. RGPE/RGLE: Table 16 text LPC OPEN; meaning per 802P - verify on unit. Not stored…

Is it safe to keep using my furnace with code 45?

It depends on the cause. The furnace has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.

Can I reset Rheem code 45 myself?

You can try one reset (power off for 30 seconds, then on). If Rheem code 45 comes back, the cause is still there and a licensed technician should check it.

Who can fix Rheem code 45 near me?

Aurora Star Tech Inc. repairs Rheem furnaces in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.

Homeowner help: Furnace Not Turning On: What to Check · Furnace Blinking Light: What the Flash Codes Mean

Troubleshooting guides

Blowing cold air All brands · Furnace
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Inducer does not run / does not run on low speed Rheem · Furnace
Inducer runs 60 s then shuts off for 5 minutes, or runs continuously Rheem · Furnace
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Thermostat does not hold room temperature Rheem · Furnace

Source: 802P: 92-24161-146-02, Diagnostics and Fault Codes table, p.40-41, 48, 51; RGPE/RGLE: Table 16 p.49 / Table 20; Fig. 45 p.63. Written in our own words as a summary; always check the original manual.

General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.