Rheem Hot Water System Not Working? What You Can Do to Fix It

Is your Rheem hot water system not working the way it should? We get it. There’s nothing worse than starting your day with an ice-cold shower or finding out your hot water is not working right when you need it most.

At Fix N Flow, we’ve helped thousands of households get their hot water running again without fuss. This is a clear and practical how-to. It’s your complete guide with practical steps, expert insights, and easy-to-follow advice to get your Rheem hot water fixed.

How to Troubleshoot Your Rheem Hot Water System

1. Spot the Issue

Take a moment to step back and observe. What’s the system doing? Or more importantly, what isn’t it doing?

• Is there no hot water at all?
• Is the water lukewarm, running out quickly, or fluctuating?
• Are you hearing unusual noises from the unit?
• Is your Rheem displaying error codes, flashing lights, or beeping?

These signs can lead you to the root of the problem. Digital displays and manuals make newer Rheem units easier to diagnose. But if yours is an older model, you’ll need to pay close attention to any signs it’s giving off.

Also, don’t forget to check if the issue is affecting just one tap or the entire house. That’ll tell you whether it’s a system-wide fault or a plumbing issue isolated to one outlet.

2. Quick Fixes for Electric Rheem Systems

If you have an electric unit and your Rheem hot water heater is not working, you’ve got a few things to check before calling in the pros.

A. Check the Power Supply

This one might sound obvious, but it’s where most successful fixes begin.

• Look at your home’s switchboard or fuse box.
• If the circuit has tripped, reset it.
• Make sure the system is plugged in and the isolator switch is turned on.

If your Rheem still isn’t heating, keep reading.

B. Test the Thermostat

Your water might just be cold because of the thermostat.

• Try adjusting the temperature to around 50°C, which is the recommended maximum for households in Australia to prevent burns.
• If it’s already set correctly and you’re still not getting hot water, the thermostat might be faulty or misreading the temperature.

A malfunctioning thermostat can prevent your system from heating water efficiently, or at all.

C. Inspect the Heating Element

This is a common culprit when electric systems stop delivering.

• Make sure the power is completely off at the main switch.
• If you’re comfortable with tools and have a multimeter handy, you can test the heating element for continuity to see if it’s blown.
• Not feeling confident? That’s okay! This is one of those times it’s perfectly fine and smart to call in a licensed professional to take over. They’ll have it sorted in no time.

3. Solutions for Gas Rheem Systems

If you’re running a gas unit and facing problems, there are a few different things to look at.

A. Check the Gas Supply

No flame means no heat. So your first step is checking the gas.

• Look at your gas meter, make sure it’s switched on.
• If you’re using bottled gas, check if it’s empty.
• Test other gas appliances like your stove or heater. If other appliances are working fine, your hot water system might need a reset or it could be something that needs fixing.

B. Relight the Pilot Light

This is one of the most common quick fixes.

• Open the panel on your Rheem unit and locate the pilot assembly.
• Use the relighting instructions printed on the side of your system.
• Hold the button down after lighting to let the thermocouple heat up.

If the flame won’t stay on, your thermocouple could be faulty and will need replacing.

4. Tips for Instant Flow Units

A. Check Both Power and Gas

These systems use electricity to ignite the gas. So both need to be functioning.

• Make sure the unit has power, and look for lights or display screens.
• Check your gas supply as described above.

B. Clean the Filters

Sediment and debris can cause performance issues over time.

• Look for the cold water inlet filter and give it a good clean.
• Check to make sure that the isolation valve isn’t partially closed or clogged.

Even a small blockage here can reduce water flow and confuse the temperature sensors.

C. Try a Reset

Sometimes all it takes is a reboot.

• Find the reset button.
• Press and hold it according to your unit’s manual.
• Then wait a few minutes and try using hot water again.

If that works, great! If not, it’s time to look at error codes.

5. Rheem Water Heater Troubleshooting Guide

Modern Rheem units are smart. When there’s a problem, they will display an error code to help you pinpoint the issue.
Check what the error code means in the Rheem water heater troubleshooting manual, or give our team at Fix N Flow a call for fast support.

6. When It’s Time to Call a Pro

DIY can be great, but there are moments when it’s safer to hand things over. If any of these signs show up, reach out to our team:

• Strong gas smells
• Persistent error codes despite resets
• Burning electrical smells
• Leaking water or rust-coloured water
• No water flow at all

7. How to Prevent Future Issues

Want to keep your hot water running smoothly? A little regular maintenance can save you a lot of stress later.

• Flush the tank every 6–12 months to keep sediment away.
• Inspect the anode rod once a year. This protects your tank from corrosion.
• Service your unit annually, especially before winter.
• Install a tempering valve if you don’t already have one. It adds safety and longevity.
• Keep the area around your unit clear, especially for gas systems, so nothing blocks airflow or interferes with safe operation.

Final Thoughts

By now, hopefully you’ve sorted the issue. And if your Rheem hot water system still isn’t working? That’s exactly where we step in. Give us a call on 1300 319 275 or fill out our online form, and we’ll get things flowing again in no time.

At Fix N Flow, we’re here to make things simple. Fast service, real solutions, and no runaround, just warm showers and happy households.