Rinnai is a household name for hot water in Australia, for a very good reason – a trusted brand for keeping that hot water absolutely steaming hot! But that doesn’t mean your Rinnai won’t break down, or at least run into the odd problem – because in the typical life of a Rinnai, it will keep literally tens of thousands of showers and baths hot per household. And while there are numerous Rinnai hot water system troubleshooting guides out there, many are just for marketing, or the information is too generic. Put simply, they’re guides that are mainly compiled by flicking through a Rinnai manual rather than the actual, real-life queries plumbers like us receive just about every day about their real-life, hard-working Rinnai hot water systems.

The real-world guide to Rinnai hot water problems

Rinnai hot water not working? This Rinnai troubleshooting guide is different. It’s perhaps the only faithful compilation of real-world questions and problems specific to Rinnai systems, put together and answered by real-world plumbers who get their hands dirty with Rinnai systems of every age and type every day.

Together, we’ll help end your Rinnai problems:

1. No water at all from my Rinnai system

If your Rinnai is churning out cold rather than hot water, the most common reason is that it’s a gas system that isn’t getting gas! Error code 11 is super-common, indicating a problem with the igniter – although the gas could simply be turned off as well. In the absence of an error code, look into whether the system’s temperature settings have been accidentally changed.

2. How do you reset a Rinnai water heater?

Perhaps there’s been a power outage, you want to clear an error code, or things just aren’t running right. To reset your Rinnai, find the control panel, and restart it – by turning off the power supply, waiting a minute or two, and restoring the power. If your particular Rinnai model has an actual reset button though, that’s even better.

3. Why is my Rinnai hot water heater not working and showing Error Code 11?

As we implied in Q1, it’s a very common one! But it doesn’t necessarily result in you having no hot water at all. However, something has gone wrong with the ignition. It could be no gas, it could be a faulty, dirty or misaligned igniter, or it could be a flame rod issue.

4. Why is my Rinnai water system not working while it’s leaking?

While the odd release of a small amount of water indicates normal valve function, a steady or excessive release of water could mean those valves have actually gone wrong. Then again, the tank could be corroded – which is very bad news. But perhaps it’s just a loose fitting or connection rather than a clear sign that your Rinnai’s useful days are over.

5. What does error code 12 mean on a Rinnai?

Error Code 11 is common, and so is Error Code 12! Basically, it’s just telling you about a flame failure, although the actual reason for that can vary. The gas supply could be low, venting may not be happening properly, or the flame rod might be faling. So check that gas, check the vent system – or call a plumber.

6. How do I re-light a Rinnai pilot light?

If your Rinnai is fairly new, it perhaps doesn’t have a traditional pilot light at all but electronic ignition instead – which would definitely explain why it’s proving hard to re-light! If your older Rinnai definitely has a normal pilot light, you’ll need to pull out that manual and follow the specific steps, but it’s usually just turning the gas control knob to ‘pilot’ and igniting the pilot whilst holding down the reset button.

7. Why is my Rinnai producing lukewarm water?

You want a satisfying steamer, but instead you’re getting a lukewarm fizzer. It could be the thermostat that’s on the way out, but then again it might be something as simple as a half-closed gas valve. Then again, the heat exchanger might be clogged or hard water might have caused scaling, in which case you’ll need a good hot water repair plumber.

8. How do I increase the temperature on a Rinnai electric hot water system?

It seems like a similar question to #7, but the solution is probably simpler – find that control panel and send the temperature in the upward direction. You might even have a new electric hot water system model with a remote, which can be used – but bear in mind that most hot water temperature in Australia is restricted due to the scalding risk.


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9. Why did my Rinnai gas hot water system just suddenly turn off?

The main cause of a sudden but apparently-routine shutdown of your Rinnai gas hot water system is overheating – so you might be seeing Error Code 16. Then again, it could be a ventilation issue (Error 10) or an unspecified system fault (Errors 70, 71 & 72) – and for these you’ll need a plumber or technician.

Your Rinnai rescue team at Rapid Service Plumbing

Rinnai hot water system not working? The solutions and insights you see above are all courtesy of the real-world customers and plumbers of Rapid Service Plumbing. Our friendly plumbers Sydney wide are serious experts in dealing with Rinnai hot water systems of every kind, age and condition, offering expert guidance and fast, affordable solutions. Rapid Service Plumbing stand out from the crowd with our lifetime workmanship guarantee and a range of other service goodies, so for fast help 24/7, don’t hesitate to give us a shout day or night.