Furnace does not ignite, burner does not start, control shows E01 shortly after a call for heat.

Safety first: Turn off the main gas cock to the Viadrus furnace and isolate electrical power at the breaker before opening any panels. Allow the combustion chamber to cool.

• Check gas supply: Verify the main gas cock to the furnace is open and that other gas appliances in the house work. If there is no gas supply, contact your gas provider.
• Inspect ignition electrode: Remove the burner access cover. Locate the ignition electrode on the burner ramp. Check for cracks in the ceramic insulator, heavy soot, or corrosion on the tip. Clean the tip gently with fine emery cloth and wipe with a dry cloth.
• Verify electrode gap and position: Refer to the Viadrus furnace manual for the specified gap (typically 3–4 mm) and distance from the burner head. Adjust carefully using needle‑nose pliers so the spark is directly in the gas stream.
• Check ignition cable: Inspect the high‑voltage cable from the ignition transformer/ignition module to the electrode for burns, cuts, or loose connections. Reseat the connectors firmly.
• Test gas valve coil: With power off, disconnect the gas valve coil connector on the gas valve assembly. Measure coil resistance with a multimeter and compare to Viadrus specifications. If open or shorted, replace the gas valve assembly.
• Reset and test: Restore power and gas, then reset the control (if applicable) and call for heat. If E01 returns after these checks, the ignition control module or main control board may be defective and should be diagnosed by a qualified Viadrus technician.