R
16
Moderate
Rinnai · Tankless Water Heaters
Outgoing water temperature exceeded safety threshold.
Quick Answer
Error code 16 on your Rinnai Tankless Water Heaters means: Outgoing water temperature exceeded safety threshold.. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
RE199iNRU199iNRUCS65iNV53e
Likely Causes
  1. Scale buildup reducing heat transfer
  2. Flow restriction
  3. Control valve problem
  4. Combustion overfire condition
How to Fix It
1
Turn off unit and let it cool.
2
Flush heat exchanger to remove scale.
3
Check inlet filter and water flow.
4
Restart and monitor outlet temperature.
5
Call service if high temperature warning recurs.
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Related Error Codes
Video Guides
Loading video guides…
Search more on YouTube →