I'm getting an error code 14 on a Rinnai 1004 F wall heater. I've unplugged overnight but still get the code.

SOURCE: Power reset - Rinnai 1004

Actually the Rinnai 1004 has an E2prom chip in it that should hold your last setting. If there is a power outage longer than 12 hours, you may have to reset it. A UPS may not supply enough power to keep the unit running. I have seen a battery with inverter setup but very costly. Try and unplug you heater for a few hours and see if the settings stayed. Extend the durration until you find the point of no return. Check all the error codes stored in the unit by holding down on the Economy button as well as the up and down arrows all at the same time. Because you will need both hands to do this, get a friend to write them down as they are displayed.

SOURCE: Getting an FH error code during the cycle count down

The FH code indicates it is not detecting water fill at the flow meter. Since you say that the washer is filling okay, I would check the wiring between the flowmeter and the control board. A common cause of this problem on this machine is the wiring harness jiggling loose. Unplug and reseat the wiring harness and see if it clears up the problem. Also look for and clean out any corrosion build-up where the harness plugs in. Hope this helped and best wishes.

SOURCE: Rinnai 1004 F Error Code 11

Code 11 is that the unit is trying to light but does not sense a flame after 5 seconds. Usually means you have run out of gas if you are bottled gas. Check your bottles are turned on if you are on LPG, you might need to change over manually. Have you anything else on gas?

SOURCE: my rinnai 1004 keep shuting off and is blinking 14

CODE DISPLAYED FAULT REMEDY 11 Ignition Failure Check that gas is turned ON. Service call if repeated. 12 Flame Failure Check that gas is turned ON. Service call if repeated. 14 Overheat Clean filter. Service call if repeated. [1] 16 Room Overheat Lower room temperature to less than 104°F (40°C). 31 32 Room Temperature Sensor Faulty Service call. 33 34 Overheat Temperature Sensor Faulty Service call. 49 Sensor Breakdown Service call. 53 Sparker Failure Service call. 61 Combustion Fan Failure Service call. 70 Faulty ON/OFF Switch Service call. 71 Faulty Solenoids Service call. 72 Faulty Flame Rod Service call. 73 Communication Error Turn heater OFF, then ON again. 99 Flue Block Check around the flue terminal for blockage. [2] [1] Remove any obstructions. The flue needs to be kept clear to expel exhaust gases. If the appliance fails to operate contact a qualified service agency. [2] If the fusible link needs replacement, it must be done by a qualified service agency. In addition, the cause of the overheat needs to be determined. The fusible link is a one use safety device that breaks to shut off the appliance.