Rinnai i-Series (previous generation) 400 — Pressure Sensor
400
Pressure Sensor. • Check sensor wiring for damage. • Measure the voltage of the sensor. • Replace if necessary. The table classifies it as Diagnostic Code.
Applies to
This sensor fault code is displayed by the I-Series control (numeric diagnostic codes) on Previous-generation I-Series solo models (i060SN, i090SN, i120SN, i150SN), as documented in Rinnai I-Series Condensing Solo Boiler Installation and Operation Manual, doc 800000112 (hosted on the Rinnai Canada i060SN product page), Section 12.8 Diagnostic Codes (800000112). Codes can differ between controller generations, so always check the manual that matches your unit.
- Rinnai i-Series (previous generation)
- Rinnai i060CN
- Rinnai i090CN
- Rinnai i120CN
- Rinnai i060SN
- Rinnai i090SN
- Rinnai i120SN
- Rinnai i150SN
Controller: I-Series control (numeric diagnostic codes). Source manual: 800000112.
Why a code is not a diagnosis
A sensor code usually means the sensor, its wiring or its mounting is faulty; the physical condition the sensor measures (temperature, pressure, flow) may be perfectly normal.
Safe things to observe
- Note the code; there is no homeowner-accessible check for sensor circuits.
- If the appliance still runs, watch whether the code returns and report it when you call.
Do not
- Do not open the appliance to test or replace sensors yourself.
How professional service helps
- A technician measures the sensor and harness against the manual's values and replaces the faulty component.
- 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
- Rinnai I-Series Condensing Solo Boiler Installation and Operation Manual, doc 800000112 (hosted on the Rinnai Canada i060SN product page), Section 12.8 Diagnostic Codes · 800000112 · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.