Rinnai Error Code 65: Water Flow Control Valve

Severity
Warning
Type
digital display
Where to look
front panel
Estimated repair cost: $150 — $350 (parts + labor)
Warning: Your Rinnai water heater is locked out due to a water flow issue. It's safe, but needs professional attention.

How to Fix Rinnai Code 65

  1. Step 1: Turn off the power to your water heater at the circuit breaker for safety.
  2. Step 2: Check if the water pressure is within the correct range (20-80 PSI). If not, adjust it or call a plumber.
  3. Step 3: Call a professional HVAC technician to diagnose and fix the issue.

How to Reset Rinnai Code 65

  1. Turn off the unit using the power button on the front panel.
  2. Turn off the gas supply valve.
  3. Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
  4. Restore power at the breaker, then open the gas valve.
  5. Turn the unit back on. If the error returns, the underlying issue needs repair.

Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.

What Does Rinnai Error Code 65 Mean?

Error code 65 on your Rinnai water heater indicates a problem with the water flow control valve. This valve ensures water flows at the correct rate for heating. If it's not working properly, your heater may not function or could overheat, leading to a lockout. This is a yellow hazard level as it's safe to use your heater, but it needs to be fixed by a professional.

Common Causes

  • Faulty water flow control valve
  • Clogged or restricted water inlet or outlet
  • Incorrect water pressure
  • Wiring or electrical issues with the valve

Diagnostic Steps

If... Check Expected
Heater is locked out Water pressure at the inlet 20-80 PSI
Water pressure is within range Flow control valve for continuity No continuity (open) or continuity (closed)

Applicable Rinnai Models

Replacement Parts

Part OEM Number Est. Cost Where to Buy
Water Flow Control Valve RIN-1000000000000

Related Codes on Same Models

Other codes that affect the same Rinnai model families as 65.

Code Description Severity
02 Stagnant Water Detection Warning
10 Air Supply/Exhaust Blockage Warning
11 No Ignition Warning
12 Flame Failure Warning
14 Thermal Fuse Warning
16 Over-Temperature Warning
19 Electrical Grounding Warning
25 Condensate Overflow Warning
29 Condensate Neutralizer Warning
31 Inlet Thermistor Failure Warning