Seeing a code on your Rinnai controller? Here is what every Rinnai continuous flow error code means, what you can safely check yourself, and when to call a licensed Perth plumber.
Rinnai Hot Water System Error Codes Explained
If your Rinnai hot water system is showing a code, it is telling you what has gone wrong. A few Rinnai codes clear with a simple reset or a quick check, but most point to a fault that needs a licensed plumber or gas fitter. This guide explains every Rinnai continuous flow error code using Rinnai Australia’s own listings, what you can safely check yourself, and when to call us.
Codes can vary between models, so always confirm against the owner’s guide for your exact unit. If the fault involves gas, or you are unsure, stop and call a licensed professional. We service Rinnai hot water systems across Perth every week.
How to Find and Read the Error Code on Your Rinnai System
Most Rinnai continuous flow (instantaneous) gas systems, including the Infinity range, display a code on the temperature controller inside your home. When the unit faults, the controller shows a number (or letters such as LC) instead of the set temperature. Rinnai’s Efinity electric continuous flow units use E-codes, and the older battery-ignition Flowmaster 10 does not display numeric codes at all.
Write down the exact code and the model number from the compliance plate on the unit before you call. It helps us arrive with the right parts.
How to Reset Your Rinnai Hot Water System
For most codes, the safe first step is a reset:
- Turn off the hot tap you were running.
- On the Rinnai controller, press the ON/OFF button to switch the unit off, then on again. If your system has a power point or isolation switch, you can switch it off for about 30 seconds instead.
- Run a hot tap and check whether the code has cleared.
A few Rinnai codes have their own specific steps: for code 03 (power interruption during a bath fill), turn off all hot taps and press the ON/OFF button twice. For code 55 (a service reminder), press the On/Off button five times to reset the reminder. If any fault code returns after a reset, note it down and book a service call. Do not open the unit or touch gas components yourself.
Rinnai Gas Continuous Flow Error Codes (Full List)
The table below lists the Rinnai gas continuous flow error codes from Rinnai Australia’s official listing. Most codes are technician-level faults, so the safe action for a homeowner is usually to book a service call.
| Code | What it means | What to do |
|---|---|---|
| No code | Noticeable reduction in water flow | The inlet water filter needs cleaning. See your manual, or book a service. |
| 03 | Power interruption during a bath fill; water will not flow when power is restored | Turn off all hot taps and press the ON/OFF button on the controller twice. |
| 05 | By-pass flow control failure | Book a service call. |
| 10 | Air supply or exhaust blockage (or a blocked condensate pipe on condensing models) | Clear anything blocking the vents or flue, and on indoor units check the air filter. If it returns, book a service. |
| 11 | No ignition (unit stops without the flame igniting) | Check your gas is on and, for LPG, that the bottle is not empty, then reset. If it returns, book a service. |
| 12 | Flame failure, low gas flow or earth leakage | Check your gas supply and reset. If it keeps happening, book a licensed gas fitter. |
| 14 | Thermal fuse or overheat switch activated (unit runs then stops) | Turn the unit off and book a service call (often caused by scale in the heat exchanger). |
| 15 | Venturi control failure | Book a service call. |
| 16 | Over-temperature warning (95°C safety lockout) | Turn the unit off and book a service call. |
| 17 | Venturi blockage | Book a service call. |
| 19 | Electrical earth check fault | Book a licensed technician. |
| 21 | Data transfer error or incorrect dipswitch setting | Book a service call. |
| 25 | Neutraliser tank sensor fault (condensing models) | Book a service call. |
| 32 | Outgoing water temperature sensor failure | Book a service call. |
| 33 | Heat exchanger thermistor failure | Book a service call. |
| 34 | Combustion air temperature sensor fault | Book a service call. |
| 38 | Exhaust temperature thermistor failure | Book a service call. |
| 41 | Frost protection thermistor failure | Book a service call. |
| 51 | Inlet thermistor failure | Book a service call. |
| 52 | Gas valve failure | Book a licensed gas fitter. |
| 54 | High exhaust gas temperature | Book a service call. |
| 55 | Service Soon reminder | A time-based service reminder. Book a service, and reset the reminder by pressing On/Off five times. |
| 61 | Combustion fan failure | Turn the unit off and book a service call. |
| 65 | Water flow control failure (does not stop flow properly) | Turn off the water and book a service call. |
| 66 | Bypass flow control fault | Book a service call. |
| 70 | PCB (control board) failure | Book a service call. |
| 71 | Gas solenoid valve failure | Book a licensed gas fitter. |
| 72 | Flame rod circuit error (unit does not operate) | Book a licensed gas fitter. |
| 92 | Neutraliser life warning (condensing models) | Book a service to change the neutraliser. |
| LC | Scale build-up inside the heat exchanger | Book a service to flush and descale the heat exchanger. |
| 5E (SE) | Cascade connection failure (commercial multi-unit systems) | Book a service call. |
Stuck on a Rinnai Error Code?
Most Rinnai codes need a licensed plumber or gas fitter. We carry common parts and can often diagnose the code and restore your hot water the same day, with upfront fixed pricing.
Rinnai Efinity Electric Continuous Flow Codes
Rinnai’s Efinity electric continuous flow units (ECF19I50 and ECF19I60) use a different set of codes:
| Code | What it means |
|---|---|
| E1 | Sensor failure |
| E2 | Outlet temperature exceeds 75°C |
| E3 | Outlet temperature exceeds 85°C |
| EC | Communication error between PCB boards |
These involve electrical components, so they should be diagnosed by a licensed plumber and electrician. Note the code and call us.
Rinnai Flowmaster 10
The Rinnai Flowmaster 10 is a battery-ignition unit and does not display numeric error codes. Instead, faults show up as symptoms. If the burner will not ignite, check the gas is turned on at the water heater and the meter or cylinder, and replace the battery. If the pilot lights but the main burner does not, check the water pressure and the battery. For anything beyond these checks, or if you smell gas or see a leak, book a service call.
Common Rinnai Error Codes Explained in Detail
Rinnai error code 11 (no ignition)
Code 11 is one of the most common. It means the unit tried to light but could not. The usual cause is simply no gas: a closed isolation valve, an empty LPG bottle, or a gas outage. Check that other gas appliances work, make sure any isolation valves are open, and reset the unit. If the gas is on and code 11 returns, the ignition system or gas valve needs a licensed gas fitter.
Rinnai error code 12 (flame failure)
Code 12 means a flame failure, low gas flow or earth leakage: the burner lit but the flame dropped out. Causes overlap with code 11 and also include low gas pressure or a flame-sensing fault. Check your gas supply and reset once. If it keeps tripping, it needs a licensed gas fitter.
Rinnai error code 14 (thermal fuse or overheat)
Code 14 means the thermal fuse or overheat switch has activated and shut the unit down. It is often caused by scale build-up in the heat exchanger or restricted flow. There is no safe home fix, so turn the unit off and book a service.
Rinnai error code 16 (over-temperature)
Code 16 is an over-temperature warning, a 95°C safety lockout. It can be caused by restricted airflow, a blocked heat exchanger or a sensor fault. Turn the unit off and book a service.
Rinnai LC code (scale build-up)
LC means limescale has built up inside the heat exchanger, which is common in hard-water areas. The unit needs flushing and descaling by a technician. Booking a regular service helps prevent it coming back.
Reduced water flow (no code)
If there is no code but your hot water flow has dropped noticeably, the inlet water filter usually needs cleaning. This is a simple maintenance job you can do following your manual, or we can take care of it during a service.
When to Call a Licensed Plumber or Gas Fitter
Cleaning the inlet water filter, checking your gas supply, and resetting the unit are safe. Beyond that, hot water repairs, especially anything involving gas, are licensed work by law in Western Australia. Call a licensed professional if:
- A code returns immediately after a reset.
- You see codes for the gas valve, flame, fan, heat exchanger or overheating (such as 12, 14, 16, 52, 61, 71 or 72).
- You can smell gas. Turn the gas off at the meter if it is safe, ventilate the area, avoid anything that could spark, and call us straight away.
Faulty gas appliances can produce carbon monoxide, which is odourless and dangerous, so never keep resetting a unit that will not run properly.
How to Prevent Rinnai Hot Water Faults
- Have your system serviced periodically, especially in hard-water areas where scale (code LC) builds up.
- Keep the flue, vents and the area around the unit clear.
- Clean the inlet water filter as recommended in your manual, particularly if your flow has dropped.
- Deal with small issues early, before they turn into a breakdown.
Frequently Asked Questions
How do I reset my Rinnai hot water system?
For most codes, turn off the hot tap, press the ON/OFF button on your Rinnai controller off and then on (or switch off the power point for about 30 seconds), then run a hot tap. For code 03, turn off all hot taps and press ON/OFF twice. For the code 55 service reminder, press On/Off five times. If a fault code returns, note it down and book a service call.
What does Rinnai error code 11 mean?
Code 11 is a no-ignition fault, meaning the unit could not light. The most common cause is no gas, such as a closed valve, an empty LPG bottle or a gas outage. Check your gas supply and reset. If it returns with the gas on, a licensed gas fitter should check the ignition system and gas valve.
What does Rinnai error code 12 mean?
Code 12 is a flame failure, low gas flow or earth leakage fault, where the burner lights but the flame drops out. Check your gas supply and reset once. If it keeps happening, call a licensed gas fitter.
What does the Rinnai LC code mean?
LC indicates limescale build-up in the heat exchanger, which is common in hard-water areas. The unit needs flushing and descaling by a technician, and regular servicing helps prevent it.
Can I fix a Rinnai error code myself?
You can safely clean the inlet water filter if your flow has dropped, check that your gas is on, and reset the unit. Anything involving gas components, the heat exchanger, sensors, the fan or electrical parts, or a code that keeps returning, should be handled by a licensed plumber or gas fitter.
Why does my Rinnai keep showing an error code?
A code that returns after a reset usually means an ongoing fault, such as scale build-up, a gas supply problem, a failing sensor, fan or valve, or a flue restriction. It needs a professional diagnosis rather than repeated resets.
Is it safe to keep using my Rinnai with an error code?
If the unit will not run properly or the code involves gas, flame, the fan or overheating, do not keep resetting it. Faulty gas appliances can produce carbon monoxide. Turn it off and call a licensed gas fitter.
Rinnai Hot Water Repairs in Perth
Proud Plumbing & Gas repairs and services Rinnai hot water systems across the Perth metro area, 7 days a week, with 24/7 emergency help, a $0 call-out fee and upfront fixed pricing. Our licensed plumbers and gas fitters carry common parts, so in many cases we can diagnose the code and restore your hot water the same day. You get a fixed price after a quick assessment, so there are no surprises.
Stuck on a Rinnai error code? Call us on (08) 6185 3008, or read more about our hot water services and Rinnai hot water systems. For urgent breakdowns see our 24/7 emergency plumbing, and for gas faults our gas fitting team can help.
