E08
Roca Combustion Fan / Air Pressure Switch Fault

Furnace shows fan or air pressure error, burner does not light, fan may not start or runs briefly

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Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

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Possible Causes

Faulty combustion fan motor, Blocked air intake or flue, Defective air pressure switch, Split or blocked pressure tubing

How to Fix / Troubleshooting

Safety first: Isolate power and gas. Wait for moving parts to stop before touching the fan assembly.

  • Check air intake and flue: Ensure both intake and exhaust terminals are clear. Remove any obstructions.
  • Inspect fan: Remove the combustion chamber cover. Check the fan wheel for dust buildup or foreign objects. Spin the wheel by hand (power off) to ensure it moves freely.
  • Examine pressure switch tubing: Locate the silicone tubes from the fan housing to the air pressure switch. Check for cracks, disconnections, or water inside. Replace or dry tubing as needed.
  • Listen for fan operation: Restore power and call for heat. If the fan does not start, check the electrical connector and supply to the fan. A non-running fan usually requires replacement.

Warning: Do not bypass the air pressure switch; it protects against unsafe combustion conditions.

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Repair Difficulty

Hard 4/5

Required Part

Combustion Fan Assembly
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