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Rinnai Error Code E04: Voltage interruption / error read-out interrupted (Boiler)

Updated · by Aurora Star Tech Inc.

Rinnai error code E04 on a boiler means: Voltage interruption / error read-out interrupted. It is also called Rinnai diagnostic code E04.

Medium severityBoilerE-Combi (E50CRN · E75CRN/E75CRP · E110CRN/E110CRP)

Homeowner? What Rinnai code E04 means for you

Check, then call Your boiler is reporting: Voltage interruption / error read-out interrupted. This is often caused by something simple. Try the safe checks below; if the code returns, book a service call before it turns into a no-heat or no-hot-water emergency.

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.

Call (647) 657-2977Book a service call

Licensed technicians serving Vaughan, Toronto and the GTA.

What does Rinnai error code E04 mean?

Message shown when power to the boiler was cut while an error was being read, once power returns and the original error is gone.

Applies to: E50CRN; E75CRN; E75CRP; E110CRN; E110CRP

Common causes of Rinnai code E04

  • Power switched off during an error read-out
  • Controller fault if it keeps coming back without a preceding error
Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.

Other Rinnai Boiler codes

CodeMeaning
Block 67Supply/return sensor difference with burner off
Block 85No water flow detected
COdEAccess code entry
CopyFactory settings restored
E00Poor flame formation (flame sensed with burner off)
E02No flame formation (ignition failure)
E05Adjustment error (listed in short reference)
E12High limit stat open
E14Supply sensor T1 fault
E18Maximum supply temperature exceeded
E19Maximum return temperature exceeded
E28Fan speed not reported back

All Rinnai Boiler error codes →

Rinnai code E04: homeowner questions

What does Rinnai code E04 mean?

Voltage interruption / error read-out interrupted. Message shown when power to the boiler was cut while an error was being read, once power returns and the original error is gone.

Is it safe to keep using my boiler with code E04?

It depends on the cause. This is often caused by something simple. Try the safe checks below; if the code returns, book a service call before it turns into a no-heat or no-hot-water emergency.

Can I reset Rinnai code E04 myself?

You can try one reset (power off for 30 seconds, then on). If Rinnai code E04 comes back, the cause is still there and a licensed technician should check it.

Who can fix Rinnai code E04 near me?

Aurora Star Tech Inc. repairs Rinnai boilers in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.

Homeowner help: Boiler Not Heating: What to Check

Troubleshooting guides

Source: Rinnai E-Combi Series Installation & Servicing Instructions (8U516009 V0116), p.71-76 (15.1, 15.3). 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.

Emergency Boiler Repair

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