What does error code 52 mean on a Rinnai tankless water heater?

Gas valve. A fault with the gas valve.

When should I call a technician for code 52?

Gas valve work is only for a qualified gas technician. Don't adjust the gas valve; Rinnai says adjustment voids the warranty. Smell gas? Leave right away, don't touch light switches or phones inside, and call your gas utility or 911 from outside. Never open a gas valve, burner, gas line, vent or flue connection, or bypass a safety switch. Repeated lockouts, scorching, soot, or a CO alarm mean shut it off and call a licensed gas technician.

Rinnai tankless water heater error code

Rinnai tankless water heater code 52: Gas valve

Rinnai tankless water heaters

What 52 means

A fault with the gas valve.

Likely causes

Gas valve or wiring fault

Safe first checks

Note the code.

When to stop

Gas valve work is only for a qualified gas technician. Don't adjust the gas valve; Rinnai says adjustment voids the warranty.

Checked against: Rinnai: Troubleshooting Tankless Water Heater Diagnostic Codes (100000652). Codes can differ by model and year, so confirm with your owner's manual.