John Wood water heater produces no hot water at all; burner or elements never turn on

Safety: For electric models, turn off power at the breaker before removing access panels. For gas models, turn gas control to OFF if you smell gas.

• 1. Verify utilities: Check that the breaker is ON for electric models and that the gas shutoff valve is open for gas models.
• 2. Reset high limit (electric): Remove the upper access panel and insulation. Press the red reset button on the upper thermostat. If it clicks, it was tripped. Replace the cover and restore power.
• 3. ECO on gas models: If the gas control's ECO has tripped (often indicated by no pilot and no reset), the gas control must be replaced.
• 4. Test thermostats and elements (electric): Use a multimeter to check for continuity and proper voltage switching. Replace any failed thermostat or element with John Wood-specified parts.