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.
Accuracy notes
The timings are the manufacturer's own and are exact, not approximate: the air pressure switch not detected for 7 seconds before ignition, or cut off for 2 seconds during normal operation. Girard names two root causes — a faulty motor, or a blockage in the air supply or the exhaust. On an RV the blockage is the one worth checking first, since the intake and exhaust sit in an exposed sidewall.
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).
Related · Girard water heater
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Sources
- Technical Manual — Girard GSWH-2 Demand Tankless Water Heater — Error Codes on User Control Panel; Troubleshooting sections (Girard Products (Lippert))
- 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)
● Checked against 3 manufacturer documents · Last verified 2026-08-09 · compiled from manufacturer documentation. Codes can vary by model year — always cross-check your unit’s manual. How we verify