Rinnai Boiler: Force the burner on for combustion checks (SERV function 1)
Force the burner on for combustion checks (SERV function 1) on a Rinnai boiler: SERV chapter test functions: 1 = burner at adjustable load, 2 = fan, 3 = pump, 4 = showroom mode. Function 1 is what you use for the O2 / CO2 check and the ionization reading.
Applies to: E50CRN; E75CRN; E75CRP; E110CRN; E110CRP
How to fix force the burner on for combustion checks (serv function 1): step by step
- Enter C123, press MODE until SERV
- Press STEP to pick function 1
- Raise the load with +; hold - to go down to OFF, which ends the test
- Target O2 at minimum 4.4 % on natural gas, 4.8 % on propane; ionization at least 4 uA
If the unit shows an error code, look it up: Rinnai Boiler codes
Source: Rinnai E-Combi Series Installation & Servicing Instructions (8U516009 V0116), p.58, 61-63. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.