Rinnai RJ12RML User Instructions page 30

Issues of hot water supply and temperature
Hot water
temperature is
unstable
Unable to adjust hot
water temperature
setting
Issues of front panel control, remote control (if applicable) and appliance operation
ON/OFF indicator
does not light up
Hot water
temperature setting
change automatically
Fan keeps operating
without use of hot
water
Flame failure during
usage
Cloudy mist emerges
from flue terminal
Hot water turns milky
with a cloudy status
Water is discharged
momentarily from the
outlet of pressure
relief valve
Troubleshooting
 Fully turn on the main water supply valve to ensure sufficient water
pressure.
 Increase hot water flow of mixing-type faucet to avoid the hot water flow
lower than the minimum hot water flow that burner will be turned off.
 When appliance is in operation, hot water temperature can only be set
to 50°C or below. If hot water temperature is set at 50°C or above, hot
water temperature can only be decreased.
 Check if the power supply is normal.
 After turning on the power supply of appliance, press the ON/OFF
button on front panel control.
 If hot water temperature is set at 55°C or above, water temperature
setting will be returned to 50°C when the priority is changed.
 After the burner is closed, combustion fan will keep operating for a short
period of time. This is a normal phenomenon.
 Fully turn on the gas meter valve and/or gas supply valve of appliance.
 Check if the gas supply is normal and without suspension.

Fully turn on the cold water valve and/or hot water tap.
 Check if the water is running out from water tap normally.

In cold and humid weather, white mist is the condensate of water
vapour in flue gases. This is a normal phenomenon.
 Dissolved air in water is released as bubbles when heated. This is
normal phenomenon.
 If the water pressure inside the appliance is over the design pressure
value, the pressure relief valve located near the hot water outlet will be
opened to release pressure. After reducing to the design pressure
value, it will then be closed.
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