Water flow control fault (bath-fill valve)
Displayed as: 65
Rinnai's RU series installation and operation manual lists diagnostic code 65 as "Water Flow Control". The manual's checks are: measure the resistance values of the water flow control, and, because the water flow control valve has failed to close during the bath-fill function, immediately turn off the water and discontinue the bath-fill function, then contact a trained and qualified professional to service the appliance.
If the water heater is leaking
- Close the cold-water shut-off valve on the pipe feeding the heater, if you can reach it safely.
- Gas unit: turn the gas control to OFF. Electric unit: switch off its breaker. Do not touch electrical parts while standing in water.
- Do not cap or plug the relief-valve discharge pipe, even if that is where the water is coming from.
A leaking tank body cannot be repaired; a dripping relief valve or fitting often can. Call CANRO with a description of where the water appears.
Applies to
This code and wording come from manual 100000467 for the RU series and relates to the bath-fill function and the water flow control valve that supports it. The cross-series document 100000652 applies the code across the 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
The code means the flow-control valve did not close as commanded after a bath-fill event, so water can continue flowing. The manual's response is immediate and practical: stop the water, abandon the bath-fill function, and call a professional; the resistance measurement identifies whether the valve or its circuit failed.
Same code, other equipment
- Rinnai non-SENSEI series: Same code family per troubleshooting document 100000652. Source
Safe things to observe
- If the unit reports code 65 during or after a bath-fill, close the fixture and the unit's water supply as the manual directs.
- Check for continuing water flow at the tub or drain.
Do not
- Do not continue using the bath-fill function after code 65.
- Do not attempt to open or repair the flow-control valve yourself.
How professional service helps
- A technician measures the flow-control valve resistance per the manual, confirms the failure, and services or replaces the valve before the bath-fill function is used again.
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
What is the bath-fill function?
A convenience feature that fills a tub to a set volume and stops automatically. Code 65 reports that the flow-control valve behind that function did not close as commanded.
What should I do immediately when code 65 appears?
The manual is explicit: turn off the water, stop using the bath-fill function, and call a qualified technician. Continuing to run water risks overflow.
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.