Maintenance indicator (service history marker)
Displayed as: FF
Rinnai's RU series installation and operation manual lists FF as a "Maintenance Indicator": a placeholder in the diagnostic code history indicating that a service provider performed maintenance or service. The service provider enters the code after service by pressing the Up, Down and On/Off buttons simultaneously, and FF is then visible on the monitor.
Applies to
This display comes from manual 100000467 for the RU series. Rinnai's cross-series document 100000652 applies the marker across the tankless generations it covers.
- Rinnai SENSEI RU (Super High Efficiency Plus condensing)
- Rinnai RU130iN
- Rinnai RU160iN
- Rinnai RU180iN
- Rinnai RU199iN
Control platform: Rinnai PC board with digital controller display. Source manual: 100000467 (rev. 07 on rinnai.ca) (2020–2021).
Why a code is not a diagnosis
FF is not a fault: it is a service-history marker that records that maintenance was performed. It appears in the diagnostic history, not as a lockout, and requires no action from the homeowner.
Same code, other equipment
- Rinnai non-SENSEI series: FF carries the same service-marker meaning per troubleshooting document 100000652. Source
Safe things to observe
- If FF appears in the history, it simply records the last service visit.
- Check the Service Soon (SS) indicator separately: SS means the next flush is due.
Do not
- Do not treat FF as a fault or attempt to clear it; it is entered by the technician who serviced the unit.
How professional service helps
- No action needed for FF itself. If the unit has never been serviced, book the manufacturer's maintenance visit and the technician will enter FF as part of the record.
Diagnostic visit
Repair visits carry a diagnostic service fee that CANRO states is credited toward the repair if you proceed. The amount is confirmed by phone; it is not published. Source, checked September 7, 2026.
Where CANRO provides on-site service
On-site service is currently offered across Metro Vancouver: Vancouver, Burnaby, Richmond, Surrey, Coquitlam, North Vancouver, West Vancouver, New Westminster, Delta, Langley, Port Moody, Port Coquitlam, Maple Ridge, Pitt Meadows, White Rock, Tsawwassen; plus Anmore, Belcarra, Lions Bay, Bowen Island, Abbotsford with travel or ferry arrangements confirmed by phone. Everything else on this site is reference information you can use anywhere in Canada.
Frequently asked questions
Does FF mean something is wrong?
No. FF is a placeholder in the diagnostic history that a service provider entered after performing maintenance. It is a record, not a fault.
How do I view the diagnostic history?
The manual's procedure displays the last nine maintenance codes: turn the unit off, then press and hold On/Off and the Up button simultaneously for two seconds.
Locked out with no hot water? Call with the code ready.
The brand, model and this code are passed along when you request service online, so the technician arrives prepared.
On-site service in Metro Vancouver, BC. Call to check availability.
Sources and verification
- Rinnai RU series Installation and Operation Manual, section 5.6 Diagnostic Codes · 100000467 · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.