Rheem Error Code 3 blinks: Limit circuit open (Furnace)

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

Rheem error code 3 blinks on a furnace means: Limit circuit open. It is also called Rheem diagnostic code 3 blinks.

High severityFurnaceRheem (-)GRC/(-)GTC 90 Plus · Rheem 90RJ/90TJ 90 Plus

Homeowner? What Rheem code 3 blinks means for you

Call a technician Your furnace is reporting: Limit circuit open. 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 3 blinks mean?

Green STATUS LED blinks 3 times: the limit circuit (main limit, rollout / overtemperature switches, or the aux. limit that the inducer wire passes through) is open or opening and closing.

Applies to: Rheem (-)GRC upflow and (-)GTC downflow/horizontal 90 Plus condensing gas furnaces (UT Electronic Controls 1012-925 / 1028-928 and Invensys ICC-H1MC7-01 IFC); Rheem 90RJ and 90TJ 90 Plus condensing gas furnaces (UT Electronic Controls 1012-925 or Invensys ICC-H1MC7-01 IFC, hot surface ignition)

Common causes of Rheem code 3 blinks

Restricted airflow - dirty filter, closed dampers or registers
Over-firing - temperature rise above the rating plate range from high gas pressure or wrong orifices
Tripped manual-reset rollout / overtemperature switch from flame rollout (blocked flue or heat exchanger)

A technician checks these and 2 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 3 blinks

Show all 23 models

90RJ04 90RJ06 90RJ07 90RJ09 90RJ10 90RJ12 90TJ04 90TJ06 90TJ07 90TJ09 90TJ10 90TJ12 RGRC-04EMAES RGRC-06EMAES RGRC-07EMAES RGRC-07ERBGS RGRC-09EZAJS RGRC-10EZAJS RGTC-04EMAES RGTC-06EMAES RGTC-07ERBGS RGTC-09EZAJS RGTC-10ERBJS

Other Rheem Furnace codes

Code	Meaning
1 blink	Soft lockout (failed ignition)
2 blinks	Pressure switch circuit open
4 blinks	Pressure switch circuit closed (stuck closed)
5 blinks	Twinning fault (optional)
6 blinks	Line and neutral reversed
10	One-hour lockout
11	Failed ignition
12	Low flame sense
13	Flame lost
14	Unexpected flame
20	Twinning fault
22	Main limit open

All Rheem Furnace error codes →

Rheem code 3 blinks: homeowner questions

What does Rheem code 3 blinks mean?

Limit circuit open. Green STATUS LED blinks 3 times: the limit circuit (main limit, rollout / overtemperature switches, or the aux. limit that the inducer wire passes through) is open or opening and closing.

Is it safe to keep using my furnace with code 3 blinks?

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 3 blinks myself?

You can try one reset (power off for 30 seconds, then on). If Rheem code 3 blinks comes back, the cause is still there and a licensed technician should check it.

Who can fix Rheem code 3 blinks 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
No heat All brands · Furnace
Short cycling All brands · Furnace
Blower does not start after burners light Rheem · Furnace
Burners go out before the heat call ends / short cycling Rheem · Furnace
Communicating system not found / no communication Rheem · Furnace
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Furnace no heat - sequence troubleshooting Rheem · Furnace
Furnace short cycles or does not hold setpoint Rheem · Furnace
Gas valve does not shut off when heat call ends Rheem · Furnace
Indoor blower does not start after burners light Rheem · Furnace
Inducer (draft motor) does not start on heat call Rheem · Furnace
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
Inducer runs 60 seconds then off for 5 minutes Rheem · Furnace
No heat - inducer (IDM) does not start Rheem · Furnace
No heat - POWER LED off Rheem · Furnace
Read target airflow from the CFM LED Rheem · Furnace
Thermostat does not hold room temperature Rheem · Furnace

Source: Rheem (-)GRC/(-)GTC Installation Instructions 92-24161-88-00, Figure 56 IFC Troubleshooting Guide, p.54 (printed); Rheem 90RJ/90TJ Installation Instructions 92-24161-32-08, Figure 53 IFC Troubleshooting Guide, p.54 (printed p.53). 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.