Gas water heaters · Australia

Rheem tankless water heater error 10

Your Rheem continuous-flow gas water heater shows 10 on its LED display. Rheem Australia classes it as abnormal low-rate combustion.

Short answer

Abnormal low-rate combustion: call Rheem Service.

What 10 means on Rheem

Rheem Australia lists code 10 on its continuous-flow gas water heaters as "abnormal low rate combustion". Rheem gives no owner checks for this code and asks owners to book a Rheem service call.

Safety first. If you smell gas, do not touch switches: leave, then call your gas emergency number from outside. Only a licensed gas fitter/plumber may open the unit, change venting or adjust gas pressure. Owners may check that outside vents are clear and reset the unit. More safety notes

Step-by-step fix

Note the code and model
Write down the code and the model number from the label on the unit.
Do not keep resetting
Do not reset repeatedly or adjust gas pressure yourself.
Book Rheem ServiceCall a pro
Rheem asks owners to call Rheem Service (13 10 31 in Australia) or use a licensed gas fitter.

Common causes

Abnormal combustion at low burner rate. Rheem does not list owner-fixable causes for this code: diagnosis is a service job.

How to prevent it

Follow the service schedule in your Rheem owner's guide

Tools & parts you may need

None for owners

FAQ

Does US Rheem use code 10 the same way?

Rheem's US models have their own manuals and code lists. We only list the meaning Rheem Australia publishes; check the manual for your model.

Sources

Rheem Australia: Troubleshooting guide (continuous-flow error codes)

Checked on 26 October 2026. Codes can differ between model generations: your own manual always wins. Spotted an error? See About & corrections.