Display shows H07; heater may overheat quickly or shut down soon after ignition.

Safety: Turn OFF power and allow the heater to cool before touching internal hot water pipes.

• 1. Power reset: Turn OFF power for several minutes, then restore and test. If H07 returns, proceed.
• 2. Access outlet thermistor (qualified persons):
  • Remove the front cover.
  • Locate the hot water outlet pipe; the outlet thermistor is attached or threaded into this pipe.
• 3. Inspect wiring and connector:
  • Check for heat‑damaged insulation or brittle wires near the hot outlet.
  • Reseat the connector at both the sensor and PCB.
• 4. Visual check of sensor:
  • If the sensor body is cracked, discolored, or shows signs of leakage, replace it.
• 5. Replace outlet thermistor: Install a genuine Panasonic outlet temperature sensor and clear the code by cycling power.
• 6. If H07 persists with a new sensor: The control PCB may be misreading the sensor and should be diagnosed by an authorized service center.