Girard Water Heater: “E8”
warning RV water heater fault codes
What it means
Air pressure (vacuum) switch fault. The switch that confirms the blower is moving air did not close within about 7 seconds before ignition, or it dropped out for ~2 seconds during operation, so the heater will not fire.
Most likely causes
- Blockage in the air intake or exhaust (insect nest, debris, obstruction) most likely
- Weak or failed blower motor not generating enough airflow common
- Disconnected, pinched, or cracked pressure-switch tubing common
- Failed air pressure switch less common
Safe checks you can do yourself
- With power off, inspect the exterior intake/exhaust for insect nests, mud daubers, or debris and clear them.
- Check that the blower spins freely and is not obstructed.
- Inspect the small pressure-switch hose/tube for kinks, cracks, or a popped-off connection.
How to reset / clear E8
- Turn the heater off at the panel.
- Power-cycle the 12V supply for ~10 seconds.
- Turn it back on and run hot water to retest.
When to call a technician
If the vents are clear and tubing is intact but E8 persists, have a technician test the blower output and the pressure switch.
Applies to
GSWH-2 · 2GWHAM
FAQ
What does Girard Water Heater code "E8" mean?
Air pressure (vacuum) switch fault. The switch that confirms the blower is moving air did not close within about 7 seconds before ignition, or it dropped out for ~2 seconds during operation, so the heater will not fire.
How do I reset Girard Water Heater E8?
Turn the heater off at the panel. Power-cycle the 12V supply for ~10 seconds. Turn it back on and run hot water to retest.
What is the most common cause of E8 on a Girard Water Heater?
The most likely cause is blockage in the air intake or exhaust (insect nest, debris, obstruction).
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Sources
- Girard Products GSWH-2 Technical Manual — GSWH-2 Technical Manual, E8 air pressure switch not detected for 7s before ignition / cut-off 2s during operation (Girard Products / ManualsLib)
- Girard GSWH-2 Tankless Water Heater Technical Manual and Troubleshooting Guide — Fault code list, E8 air pressure switch; faulty motor or air/exhaust blockage (Manuals.plus)
Note: Timing values (7s before ignition, 2s during operation) come from the manual reproductions and should be treated as the documented thresholds.
● Last verified 2026-06-29 · compiled from manufacturer documentation. Codes can vary by model year — always cross-check your unit’s manual.