13
Rheem Water Heater
Severity:What Does This Error Mean?
Code 13 means combustion gases are not being properly exhausted. This is a safety shutdown — do not bypass it. Check for a blocked vent pipe, failed blower motor, frozen condensate line, or a kinked pressure switch hose.
Affected Models
- Rheem Performance Power Vent
- Rheem Professional Power Vent
- Rheem Prestige Power Vent
- Rheem Power Direct Vent
Common Causes
- Blocked or ice-covered vent exhaust outside
- Condensate drain line blocked, backing up into the vent
- Draft inducer blower motor failed or running slowly
- Pressure switch sensing hose kinked or disconnected
- Cracked or disconnected vent pipe section
How to Fix It
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Check the vent exhaust outlet outside.
Locate the PVC vent pipe termination outside the building. Clear any debris, bird nests, ice, or insect screens clogged with lint. Even a partial blockage is enough to trip Code 13.
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Check the condensate drain line.
Power vent water heaters produce condensate that must drain freely. A blocked drain line can back up into the vent pipe. Confirm the drain line is clear and draining.
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Listen for the inducer blower starting.
When the thermostat calls for heat, the blower should start before ignition. If it is silent or laboured, the blower motor may have failed — a failed blower always triggers Code 13.
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Inspect the pressure switch hose.
A small rubber hose connects the draft switch to the inducer housing. Check for kinks, cracks, or disconnection — a compromised hose gives a false Code 13.
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Reset only after the vent is confirmed clear.
Press the reset button or cycle power. If Code 13 returns immediately, the blower or pressure switch requires professional service.
When to Call a Professional
Code 13 is a combustion safety fault. If the vent is clear and Code 13 persists, call a licensed plumber — do not reset and run the unit with an unresolved draft fault.
Frequently Asked Questions
Is it safe to reset and run with Code 13?
No. Code 13 means combustion gases may not be safely exhausted. Running the unit risks carbon monoxide buildup inside the home. Resolve the cause completely before restarting.
What is the draft pressure switch on a Rheem water heater?
It detects suction created by the inducer blower. If the blower is not pulling air at the correct rate — due to blockage or motor failure — the switch opens and triggers Code 13 to prevent unsafe combustion.