Rheem Error Code 84: Outdoor air sensor fault (Furnace)
Rheem error code 84 on a furnace means: Outdoor air sensor fault. It is also called Rheem diagnostic code 84.
Homeowner? What Rheem code 84 means for you
Usually minor Your furnace is reporting: Outdoor air sensor fault. This code is usually informational or minor. The safe checks below often clear it; call us if it keeps showing up.
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) 657-2977Book a service call
Licensed technicians serving Vaughan, Toronto and the GTA.
What does Rheem error code 84 mean?
The optional outdoor air sensor on T4 (10K NTC) read open or shorted after it had been seen as valid in this power cycle. Low-level fault: heating continues. It clears itself three minutes after it is detected and is only logged once.
Applies to: (-)96VA040-115 (R96V / U96V) and (-)(-)96MDV040-115 two-stage variable-speed communicating furnaces
Common causes of Rheem code 84
- Outdoor sensor wire broken or shorted
- Sensor unplugged after power-up
- Failed sensor
Rheem models that use code 84
96MDV040B30A96MDV060B30A96MDV070B30A96MDV085C50A96MDV100C50A96MDV115D50AR96VA0401317MSAR96VA0601317MSAR96VA0701317MSAR96VA0851521MSAR96VA1001521MSAR96VA1151524MSA
Other Rheem Furnace codes
All Rheem Furnace error codes →
Rheem code 84: homeowner questions
What does Rheem code 84 mean?
Outdoor air sensor fault. The optional outdoor air sensor on T4 (10K NTC) read open or shorted after it had been seen as valid in this power cycle. Low-level fault: heating continues. It clears itself three minutes after it is detected and is only logged once.
Is it safe to keep using my furnace with code 84?
Usually yes. Code 84 is normally minor, but if it keeps coming back have it checked.
Can I reset Rheem code 84 myself?
You can try one reset (power off for 30 seconds, then on). If Rheem code 84 comes back, the cause is still there and a licensed technician should check it.
Who can fix Rheem code 84 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
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Source: Rheem (-)96V / (-)(-)96MDV Installation Instructions 92-24161-124-08, 16 Supply and outdoor air temperature sensor inputs p.97. 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.