Girard Water Heater: “E3”
warning RV water heater fault codes
What it means
The ECO — the over-temperature cut-off thermostat — opened, either before ignition or during operation, and the heater stopped. Girard's technical manual gives the trigger precisely: under normal circumstances this happens when the water temperature at the outlet exceeds 79 °C (174 °F). The cause has to be found and removed before the unit is restarted.
Most likely causes
- Outlet water temperature climbed past the high-limit (≈140°F / 60°C) most likely
- Low or no water flow causing heat to build up in the heat exchanger common
- ECO thermostat failed open / out of spec less common
- Loose or corroded ECO wiring connection less common
Safe checks you can do yourself
- Let cool water flow through the heater for a minute or two to bring the heat exchanger temperature down.
- Check that the water filter/screen and plumbing are not restricting flow.
- Confirm the temperature setting is not maxed unnecessarily.
- Inspect the ECO connector for a loose/corroded contact (with power off).
How to reset / clear E3
- Run cold water through the system to cool it.
- Turn the heater off at the panel, wait ~10 seconds, and turn it back on.
- Restart hot water flow and watch for the code to clear.
When to call a technician
If the ECO trips repeatedly even with good water flow and a cooled heater, have a technician test/replace the ECO thermostat and check the heat exchanger.
Accuracy notes
Earlier versions of this page hedged the threshold at around 140 °F because secondary reproductions of the manual disagreed. The official Girard technical manual resolves it, and the disagreement turns out to have been two different codes being mixed together: E3 is the ECO opening above 79 °C, while E6 is the over-temperature code at 60 °C for 3 seconds. They are two stages of the same protection, not two readings of one number.
Applies to
GSWH-2 · 2GWHAM
FAQ
What does Girard Water Heater code "E3" mean?
The ECO — the over-temperature cut-off thermostat — opened, either before ignition or during operation, and the heater stopped. Girard's technical manual gives the trigger precisely: under normal circumstances this happens when the water temperature at the outlet exceeds 79 °C (174 °F). The cause has to be found and removed before the unit is restarted.
How do I reset Girard Water Heater E3?
Run cold water through the system to cool it. Turn the heater off at the panel, wait ~10 seconds, and turn it back on. Restart hot water flow and watch for the code to clear.
What is the most common cause of E3 on a Girard Water Heater?
The most likely cause is outlet water temperature climbed past the high-limit (≈140°f / 60°c).
Related · Girard water heater
The outlet (hot side) water temperature sensor reads an invalid value.… E1
Ignition failure. The igniter sparked but the board never confirmed a… E2
Flame sensing was interrupted during normal operation. The burner had… E4
The inlet (cold side) water temperature sensor reads an invalid value… E5
Blower/fan motor fault. The control board commanded the combustion… E6
Over-temperature. The outlet water temperature exceeded 60 °C (140 °F)…
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, E3 ECO open before ignition or during normal operation (Girard Products / ManualsLib)
- Girard GSWH-2 Tankless Water Heater Technical Manual and Troubleshooting Guide — Fault code list, E3 ECO open, outlet temperature exceeding ~140°F (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