RBI Err 66 — Net Freq. Error Detected in the Main
Err 66
Net freq. error detected in the main. Checks: Check the frequency signal. It must be between 58 and 62Hz Solutions: If out from range, ask your electrical supplier. Diversely try to replace the power contro board The table classifies it as Blocking error (Err).
Applies to
This electronics fault code is displayed by the IE2 control (Loc lockout and Err blocking error codes on the display) on Infinite Energy² models (IB/IW 199 through IB/IW 1000), as documented in Infinite Energy 2 (IE2) Boiler IOM, doc IE2IBIOM-3 (82-0147-001), sections 15.15-15.16 (IE2IBIOM-3). Codes can differ between controller generations, so always check the manual that matches your unit.
- RBI Infinite Energy²
- RBI Infinite Energy² 199
- RBI Infinite Energy² 399
- RBI Infinite Energy² 500
- RBI Infinite Energy² 750
- RBI Infinite Energy² 1000
Controller: IE2 control (Loc lockout and Err blocking error codes on the display). Source manual: IE2IBIOM-3.
Why a code is not a diagnosis
An electronics code points at the control board, memory or firmware. It is often triggered by poor incoming power or voltage backfeed from other wiring rather than by the appliance itself.
Safe things to observe
- Note the code and whether it appeared after electrical work or a power event.
Do not
- Do not open the control module.
- Do not repeatedly power-cycle to clear a recurring board code.
How professional service helps
- A technician checks supply voltage and grounding, follows the manual's reset sequence and replaces the module only if the code returns.
- Combustion and safety devices are verified with an analyser and the manufacturer's procedure after any repair.
Where ROMA provides on-site service
On-site service is currently offered in Greater Vancouver, BC, including Vancouver, Burnaby, Richmond, Surrey, Coquitlam, North Vancouver, West Vancouver, New Westminster, Port Coquitlam, Port Moody, Delta, Langley, Maple Ridge, Abbotsford, Chilliwack, White Rock, Pitt Meadows, Tsawwassen, Anmore, Lions Bay, Belcarra, Bowen Island, Mission. Everything else on this site is reference information you can use anywhere in Canada.
Frequently asked questions
Can I clear this code myself?
Clearing a code without fixing its cause usually just brings it back. Note the code, check the safe items on this page, then call a licensed technician. If your appliance manual describes a user reset for this exact code and it stays away, no call may be needed.
Boiler locked out? Call with the alert text ready.
The brand, model and this alert are passed along when you request service online, so the technician arrives prepared.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
- Infinite Energy 2 (IE2) Boiler IOM, doc IE2IBIOM-3 (82-0147-001), sections 15.15-15.16 · IE2IBIOM-3 · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.