Rinnai 10 Error Code: Air supply or exhaust blockage, or condensate trap full
Updated October 2026 · Sourced from Rinnai documentation
The unit detects blocked air supply or exhaust, or a full condensate trap. The manual lists a blocked condensate line, a dirty air filter, blocked vents and vent length among the things to check.
Is it safe to keep running? No. Turn it off and get it checked. Venting and combustion air are safety items. Call a qualified professional if the code returns after the simple checks. The manual warns that some checks must be done by a trained and qualified professional.
10 at a glance
| Code / how it shows | Meaning | Applies to |
|---|---|---|
| 10 Code shown on the temperature controller display | Air supply or exhaust blockage, or condensate trap full | SENSEI N Series residential condensing: RU199i, RU180i, RU160i, RU130i (indoor) and RU199e, RU180e, RU160e, RU130e (outdoor) |
Check this first
Only steps a homeowner can do safely. Do not open electrical panels or the burner area.
- Look at the outdoor vent terminals for blockage (leaves, snow, nests). Do not open vent pipes.
- Check that the condensate drain line is not blocked or frozen where you can see it.
- The manual describes cleaning the internal air filter (section 6.2, indoor units): power off first. If unsure, have a professional do it.
🛑 Stop and call a licensed pro if
- Venting and combustion air are safety items. Call a qualified professional if the code returns after the simple checks. The manual warns that some checks must be done by a trained and qualified professional.
- You smell gas. Leave the house, do not touch switches, and call your gas utility from outside.
- Codes for flame failure, overheating, venting or the control board that return after one reset.
- Water leaking from the heater, the relief valve discharging, or scorching around the burner area.
- A carbon monoxide alarm sounds. Get everyone outside and call 911 or the fire department.
Safe first steps for any Rinnai code
- Write down the exact code shown on the controller or the number of status light flashes.
- Turn the water heater power off and back on (or press the reset button the manual describes) once. If the code comes back, stop resetting.
- Make sure the gas supply valve to the heater is open and other gas appliances in the home are working.
- Make sure the cold water supply valve is fully open and hot water taps are not partly closed.
- Look at the outside vent terminal for snow, ice, leaves or anything blocking it (look only).
Source: Rinnai SENSEI N Series Residential Installation and Operation Manual (100000467), 5.6 Diagnostic Codes, p.73. Codes are series-specific, so your unit's own manual is the final word. Reviewed October 2026.
Ryan Giles · Red Seal Certified Plumber · Ask a plumber · Ask an HVAC technician