Honeywell Water Heater Error Code 5 Flashes

Five flashes on a Honeywell water heater gas control valve indicate a sensor failure within the gas control valve and thermostat assembly. The internal sensor is not a separate replaceable component, meaning the entire gas control valve must be replaced to clear this fault. The water heater should be shut down until the repair is completed.

No, operating the water heater with an active 5-flash sensor failure is not advisable. The sensor failure compromises the gas control valve's ability to accurately monitor and regulate heater operation. The unit should be shut down by turning the gas control knob to OFF and closing the main gas supply until the valve is replaced.

The cost depends on the specific gas control valve model required and whether you hire a technician. Replacement gas control valves typically range from $100 to $350 for parts alone. Adding professional labor, total repair costs generally fall in the range of $200 to $600 depending on your location and the technician's rates.

The repair requires turning the gas control knob to OFF, shutting off the main gas supply, and replacing the gas control valve and thermostat assembly. While some experienced DIYers can complete this replacement, gas appliance work carries safety risks and local codes in some areas require a licensed professional. If you are unfamiliar with gas line connections, hiring a qualified technician is strongly recommended.

A simple reset will not clear the 5-flash sensor failure code because the fault is caused by a hardware failure inside the gas control valve, not a temporary condition. The code will return as long as the faulty valve remains installed. Replacement of the gas control valve and thermostat assembly is required to resolve the fault permanently.