Rinnai Error Code 720: Flame rod fault (Combi Boiler)
Rinnai error code 720 on a combi boiler means: Flame rod fault. It is also called Rinnai diagnostic code 720.
Homeowner? What Rinnai code 720 means for you
Call a technician Your combi boiler is reporting: Flame rod fault. The combi boiler has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.
Safe things you can check yourself
- Check the thermostat: right mode (Heat or Cool), set a few degrees past room temperature, and fresh batteries if it uses them.
- Make sure the unit has power: its on/off switch (often looks like a light switch near the unit) is ON and the breaker in the electrical panel is not tripped.
- Look at the pressure gauge on the boiler. If it reads much lower than usual or near zero, or water is leaking, call a technician.
- Outside, make sure the intake and exhaust pipes or vent cap are not blocked by snow, ice, leaves or a nest.
- Check that the boiler gas valve is open (handle in line with the pipe).
- Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.
- If only hot water is missing, check that the hot water tap is open far enough to start the heater.
Call (647) 657-2977Book a service call
Licensed technicians serving Vaughan, Toronto and the GTA.
What does Rinnai error code 720 mean?
Fault in the flame sensing (flame rod) circuit.
Applies to: I-Series Plus boilers — 150K BTU and smaller and 175K BTU and higher (Combi and Solo)
Common causes of Rinnai code 720
- Frayed or broken flame rod wiring
- Loose flame rod in porcelain housing
- Cracked porcelain housing
A technician checks these and 4 other possible causes on site before replacing any part.
Rinnai models that use code 720
IP060160CIP090099CIP090160CIP090199CIP120199CIP150199CIP175199CIP199199C
Other Rinnai Combi Boiler codes
All Rinnai Combi Boiler error codes →
Rinnai code 720: homeowner questions
What does Rinnai code 720 mean?
Flame rod fault. Fault in the flame sensing (flame rod) circuit.
Is it safe to keep using my combi boiler with code 720?
It depends on the cause. The combi boiler has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.
Can I reset Rinnai code 720 myself?
You can try one reset (power off for 30 seconds, then on). If Rinnai code 720 comes back, the cause is still there and a licensed technician should check it.
Who can fix Rinnai code 720 near me?
Aurora Star Tech Inc. repairs Rinnai combi boilers in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.
Homeowner help: Tankless Water Heater No Hot Water: What to Check · Boiler Not Heating: What to Check
Source: Rinnai Troubleshooting I-Series Plus Boiler Diagnostic Codes (800000375), p.41. 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.