High pressure lockout for 4 hours, elevated from fault 31 when the stage can no longer be lowered.
Homeowner part this code names: AC coil cleaner.
Search on AmazonOpens an Amazon search for that name. Check the size against your manual. As an Amazon Associate I earn from qualifying purchases.
Bryant outdoor 84 is a high-pressure lockout for 4 hours, elevated from fault 31 when the stage can no longer be lowered. Causes include low outdoor airflow in cooling, low indoor airflow in heating, overcharge, a service valve left closed, a loose high-pressure-switch harness, a restricted filter drier, non-condensables, a faulty pressure switch, and a reversing valve stuck in cooling. In heating, the homeowner check is the indoor coil and the filter. Also check the outdoor coil for ice or debris.
Likely causes
- Outdoor airflow too low or off in cooling, including a coil blocked by ice or debris
- Indoor airflow too low or off in heating
- Overcharged system, closed service valve, or non-condensables
- Loose high-pressure-switch harness, or the switch disconnected from the inverter
- Restricted filter drier or expansion device
- Reversing valve stuck in cooling during a heating call
- On a furnace-plus-heat-pump system, the furnace running when it should not
Safe checks for 84
- In heating, with power off, check the indoor coil and the filter for debris. Also check the outdoor coil for ice or debris
- Technicianthe table says to check discharge pressure with a gauge, and to replace the pressure switch if pressure is less than 600 plus or minus 20 psig and the switch is open. Charge, valves, and the reversing valve are the same visit
Capacitors can hold a charge after the power is off. Safety terms.
When to call a pro
Call a licensed HVAC technician if 84 is stored. Code 31 was still stepping the unit down. 84 is the control stopping that.
Find a Bryant dealer (official locator, opens in a new tab) ↗Email me this fix
We save your email and this page. Nothing is emailed. We'll only use your email for this request.
Request a filter and maintenance reminder
We save your email, this page, and the interval you pick. Nothing is emailed. We'll only use your email for this request.
Parts & tools for this fix
Taken from this code's causes or steps. A search link opens Amazon results and does not confirm a fit. Check the model number in the manual.
Furnace and AC air filter: guide
In this code: In heating, with power off, check the indoor coil and the filter for debris. Also check the outdoor coil for ice or debris
See the guide for what to look for when buying one.
AC and heat pump coil cleaning supplies: guide
In this code: Outdoor airflow too low or off in cooling, including a coil blocked by ice or debris
As an Amazon Associate I earn from qualifying purchases.Affiliate disclosure