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Rinnai gas heater code 16: Room overheat

Gas heater, Australia

The heater sensed a room temperature above 40°C.

You can often clear this yourself. Work through the causes below in order, most likely first.

What causes it

  1. The room is warmer than 40°C.

    Let the room cool below 40°CYou can do this

    1. Ventilate the room, or wait until it is below 40°C, then turn the heater on again.
    2. If the code shows when the room is not hot, book a service call.

How to read this code on your unit

Models that show this code

6 models in 2 ranges
RangeModels
Energysaver FDT commercial flued gas heaterRHFE-559FTSN (Energysaver 559FDT), RHFE-1005FTSN (Energysaver 1005FDT)
Energysaver FT flued gas heaterRHFE-309FT3 (Energysaver 309FT), RHFE-559FT3 (Energysaver 559FT), RHFE-561FT3 (Energysaver 561FT), RHFE-1005FT3 (Energysaver 1005FT)

Where this comes from

Checked against the manufacturer's manual on 9 October 2026.

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Other Rinnai gas heater codes

Code Meaning What you can do
11 Ignition failure Safe checks first, then a pro
12 Flame failure Safe checks first, then a pro
14 Filter blocked or overheat You can often fix it
30 Overheat temperature sensor fault Safe checks first, then a pro
31 Room temperature sensor fault Safe checks first, then a pro
32 Room temperature sensor fault Safe checks first, then a pro
33 Overheat temperature sensor fault Safe checks first, then a pro
34 Overheat temperature sensor fault Safe checks first, then a pro
35 Overheat temperature sensor fault Safe checks first, then a pro
40 Sensor tube failure Call a pro
49 Sensor breakdown Safe checks first, then a pro
53 Spark sensor fault Call a pro