Service Soon (flush the heat exchanger)
Displayed as: SS
Rinnai's RU series installation and operation manual lists SS (Service Soon) as a time-based service indicator set during installation. SS indicates that it is time for service and that the heat exchanger should be flushed to prevent damage; the manual notes that hard water must be treated to prevent scale build-up or damage. The reset procedure is to push the On/Off button on the temperature controller five times in five seconds.
Applies to
This indicator comes from manual 100000467 for the RU series and applies when the Service Soon reminder (parameter 03) is set. Rinnai's cross-series document 100000652 lists the parameter selections: not active, 0.5 years, 1 year or 2 years.
- 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
SS is a reminder, not a fault: the unit keeps operating. The reminder interval was chosen at installation, so an SS display means the chosen interval has elapsed and the flush is due, not that the heat exchanger is already damaged.
Same code, other equipment
- Rinnai non-SENSEI series: SS carries the same service-reminder meaning per troubleshooting document 100000652. Source
Safe things to observe
- SS means the flush interval has elapsed: book the descaling visit.
- In Metro Vancouver's soft water scale is slower, but the manufacturer's interval still applies.
Do not
- Do not reset SS without actually flushing the heat exchanger; the reminder exists to protect the exchanger.
- Do not ignore repeated SS displays for years on end.
How professional service helps
- The annual or interval-based service flushes the heat exchanger through the isolation valves, cleans the inlet filter, checks the condensate trap and combustion, and resets the SS indicator per the manual.
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
Can I clear SS myself?
The manual's reset is five On/Off presses in five seconds, but the honest sequence is to have the flush done first: resetting the reminder without the service leaves the heat exchanger unprotected.
What happens if I ignore SS?
Scale builds up in the heat exchanger, which can lead to overheat codes and damage that Rinnai's warranty excludes; flushing is a warranty condition.
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
- Rinnai Troubleshooting Tankless Water Heater Diagnostic Codes (SS parameter selections) · 100000652 · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.