Bradford White Water Heater Error Code 26

Error code 26 means the vent safety switch located at the first pass collector has opened due to detected overheating. When this happens, the gas valve closes, the blower runs through a post-purge cycle, and the unit enters a hard lockout. The heater will not restart automatically and requires manual intervention after the cause of the overheating is identified and corrected.

Yes, this code represents a legitimate safety condition. The vent safety switch is designed to prevent dangerous overheating in the flue path, which could damage the unit or create a fire risk. The hard lockout condition prevents the heater from continuing to operate under unsafe conditions, so the lockout itself is protective and should be treated seriously rather than bypassed.

A reset will clear the lockout and allow the heater to attempt operation again, but it will not resolve the underlying cause. If the condition that triggered the vent safety switch is still present, the switch will open again and code 26 will return. Permanent resolution requires identifying and fixing the root cause, whether that is a blocked vent, a failed switch, inadequate combustion air, or another issue driving the overheating.

You should not reset the unit until you have inspected the vent system for blockages and confirmed there is no evidence of extreme heat damage such as discoloration, melted parts, or deformed components. If the vent path is clear and no heat damage is visible, a reset may be attempted. However, if there is any physical evidence of extreme temperatures reaching around 350 degrees Fahrenheit, you should contact Bradford White technical support before resetting.

Repair costs vary depending on the cause. If the issue is a blocked vent that you can clear yourself, there may be no parts cost involved. If the vent safety switch itself has failed and needs replacement, parts and labor could range from around 150 dollars to 350 dollars or more depending on your location and the service provider. More complex issues such as heat exchanger damage or venting system corrections would carry higher costs.