R4 🟡 Repair Required
York Error Code R4: High Limit Switch Open
⚠️ Your York furnace has shut down due to a high limit error. This prevents overheating, but you'll need to troubleshoot to restore heat.
How to Fix York Code R4
- Step 1: Replace the air filter. A dirty air filter is the most common cause of overheating. Use the filter size noted on the furnace.
- Step 2: Ensure all return air vents are open and unobstructed. Do not block them with furniture or rugs.
- Step 3: Wait 30 minutes, then try resetting the furnace by turning it off and then on again at the breaker. If the error reappears, call a qualified HVAC technician.
What Does York Error Code R4 Mean?
The R4 error code on your York furnace indicates that the high limit switch has opened. This switch is a critical safety device designed to shut down the furnace if it gets too hot. Think of it like a circuit breaker for heat. When the furnace temperature exceeds a safe threshold, the high limit switch trips, cutting off the gas supply and blower motor. This prevents potential damage to the furnace components and, more importantly, protects your home from a fire hazard. The R4 code means the furnace control board detected that the switch is open (tripped). It's important to address the underlying cause of the overheating, not just reset the system.
Common Causes of York Code R4
- Dirty air filter restricting airflow
- Blocked return air vents reducing airflow to the furnace
- Faulty blower motor or capacitor causing reduced airflow
- Overfiring furnace due to a gas valve issue
- Defective high limit switch tripping prematurely
Applicable York Models
Need a Pro to Fix York Code R4?
A licensed HVAC technician can diagnose and fix this issue quickly.
Find a Licensed Tech Near You →Replacement Parts for York HVAC System Code R4
High Limit Switch OEM: 024-36375-000
Blower Motor Capacitor
Air Filter