Rinnai 51: Gas Solenoid Valve Fault
What the Rinnai 51 error code means, what causes it, and why it's a job for a licensed BC gas technician — not a DIY reset.
Severity
High — needs prompt professional attention
Gas safety first
This fault involves gas, combustion or venting. If you smell gas (rotten-egg odour), hear hissing, or feel unwell, leave the building immediately and call 911 or FortisBC at 1-800-663-9911 from outside. Do not flip switches or relight anything. For all other cases, switch the boiler off and call a licensed gas technician.
What the Rinnai 51 error code means
The gas solenoid valve circuit reported an abnormal condition.
On Rinnai i-Series, M-Series and Q-Series, 51 is a gas-supply / gas-valve fault. It is a protective response — the boiler is telling you something needs attention, and the safe, lasting fix is a proper diagnosis rather than repeated resets.
Symptoms you may notice
- Ignition lockout or flame failure
- No heat or hot water
- Fault clears briefly then returns
Common causes of Rinnai 51
Why this is not a DIY fix
Anything touching the gas valve or gas supply — pressure, the valve itself, or supply sizing — is legally restricted to licensed gas fitters in BC. Manometer testing and gas-valve adjustment are not DIY tasks, and getting them wrong is dangerous.
In British Columbia, gas work must be performed by a TSBC-licensed gas fitter. GasBoilers.ca — a CanroHeat division — sends Red Seal–certified, gas-licensed technicians who diagnose the true cause, repair it correctly, and verify safe operation before they leave.
How our technicians diagnose & repair it
- 1Measure static and working gas pressure with a manometer
- 2Confirm the meter, regulator and gas line are correctly sized
- 3Test the gas valve and its modulation
- 4Adjust combustion to specification with analysis
Related Rinnai codes
Rinnai 51 — FAQ
What does the Rinnai 51 error code mean?
The gas solenoid valve circuit reported an abnormal condition. On Rinnai i-Series, M-Series and Q-Series, this is categorised as a gas-supply / gas-valve fault.
What causes Rinnai 51?
The most common causes are: Solenoid/valve fault; Wiring fault; Control-board output fault. A licensed technician confirms which one applies before any part is replaced.
Can I fix Rinnai 51 myself?
No. Anything touching the gas valve or gas supply — pressure, the valve itself, or supply sizing — is legally restricted to licensed gas fitters in BC. Manometer testing and gas-valve adjustment are not DIY tasks, and getting them wrong is dangerous. Repeatedly resetting the boiler without fixing the root cause can be unsafe and can cause further damage. Call GasBoilers.ca at 604-359-1081 for a licensed diagnosis.
Is the Rinnai 51 error code dangerous?
It can be. This fault involves combustion, gas or venting. If you ever smell gas, leave the building immediately and call 911 or FortisBC at 1-800-663-9911 from outside. Otherwise, switch the boiler off and book a licensed technician.
How much does it cost to fix Rinnai 51 in Greater Vancouver?
Cost depends on the root cause and any parts needed. We start with a flat-rate diagnostic, then quote the repair before any work begins — no surprises. Call 604-359-1081 for current pricing and same-day availability.
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Rinnai showing 51? We'll fix it right.
Licensed, Red Seal–certified gas technicians across Greater Vancouver. Upfront pricing, same-day service available.