HVACopediaRinnai · Wall furnace
Set back Set back indicator lit (frost protection on)
What the display is showing
The light above the Set back button is on while frost protection is active. The furnace starts heating whenever room temperature drops below the preset minimum (38 to 78°F, default 60°F), regardless of timer or manual settings. It is on by default from the factory.
Applies to: Rinnai EX08DT, EX11DT, EX17DT, EX22DT direct vent wall furnaces
What to do
- With the furnace OFF, press Set back (light comes on).
- Adjust the minimum temperature with the up/down buttons.
- Press Set back again to turn the feature off.
Settings for these units
Clearances to combustibles and service · EX DT
| Location | Clearance |
|---|---|
| Top | 0 in. (0 mm) |
| Bottom / ground | 0 in. (0 mm) |
| Front (panel) | 40 in. (1 m) - flooring or carpet under 1.2 in. (30 mm) high not included |
| Back (including back spacer) | 0 in. (0 mm) |
| Sides (left and right) | 2 in. (50 mm) |
| Service access | 10 in. (254 mm) sides; 40 in. (1 m) front; area above per figure |
| Exhaust extension pipe | 1 in. (25.4 mm) to combustibles; 0 in. to non-combustibles |
Rinnai recommends 10 in. (254 mm) at top and both sides for servicing.
Service clearance figure above the unit: 10 in. (254 mm) on EX08DT/EX11DT, 9 in. (229 mm) on EX17DT/EX22DT.
Models that show this code
5 models in EX DT
Other codes on the same units
- Lock Control panel lock indicator
- ON lamp green ON indicator green (powered, burner not lit)
- ON lamp red ON indicator red (burner lit)
- PH High-fire gas pressure setting mode
- PL Low-fire gas pressure setting mode
- Set / Room temp Display: set temperature and room temperature
- Timer lamp Timer lamp solid or flashing
- °F/°C Temperature scale selection
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Source: Rinnai EX08DT/EX11DT Installation and Operation Manual (200000083) and EX17DT/EX22DT (200000084), Set back p.35. Summarized in our own words; check the original manual for your model.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.