There is nothing worse than finding that you don’t have enough hot water when you really need it. Thankfully, homeowners can take care of a few minor Rheem water heater issues on their own.
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The first thing that you have to check is whether the heater is getting any power at all, for gas units – check the thermocouple. Always make sure that the thermostat is not set higher than 120 F and keep the parts of the unit clean and free of mineral buildup.
Fortunately, Rheem water heater troubleshooting is not nuclear physics and it’s relatively easy to find the root cause of the problem and, in a lot of cases, fix it, even if you are not a professional technician.
Safety Tips ; the Tools You’ll Need
Rheem has a wide range of water heaters available. If you decide to go for a unit that uses gas, you would have to keep these important safety tips in mind:
- Installing a carbon monoxide detector next to the heater is a must. If the device ever goes off, you have to evacuate the whole house and call a specialist immediately.
- In case you smell gas around the heater, make sure to turn the valve and do not ignite anything. Once again, you should make all the family members leave the house and call a technician.
It is incredibly important to pick the right tools when working with your water heater.
Some of the items that you might need include a screwdriver, an electrical tester, towels, a bucket, a lighter (a BBQ lighter is a right fit for the job), pipe tape, and a wrench.
Another thing that is going to come in handy is the manual that came with your Rheem heater.
Tip: don’t worry, if you accidentally threw the manual away – you’ll find all the instructions online.
How Do You Troubleshoot a Rheem Electric Water Heater?
If you have found that your electric water heater is not working to its full potential, it doesn’t necessarily mean that the unit has to be replaced.
Sometimes a minor issue can be easily fixed by the homeowner. However, always remember to call a professional, if you have any questions or if you don’t feel confident dealing with such units.
Why Is My Rheem Water Heater Not Getting Hot?
Lack of power might be to blame.
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Make sure that the circuit breaker is in the ‘on’ position. In case it is midway between ‘on’ and ‘off’, bring the breaker to the ‘off’ position and then to the ‘on’.

Tip: if such a ‘midway’ issue continues, it means that the circuit is tripping. Leave this problem to a professional.
Give your unit around 30 minutes to start producing hot water, if nothing happens, then the problem is not with the power, but with the actual unit.
Read: No Hot Water In The House? Here’s Why
There Is Not Enough Hot Water
- The heater might simply be the wrong size. If you are using more water than the unit is able to produce, then you definitely need a bigger heater.
- Never experienced such a problem before? Then there might be an issue with the thermostat or one of the heating elements.
- Have you had your Rheem water heater for over 3 years? It looks like there might be a mineral deposit buildup in the tank. Such buildups can drastically reduce the capacity of your tank.
What’s next?
You can try setting the thermostat to a higher temperature. However, do make sure that it is not higher than 120 F.
If the issue persists, then take your electrical tester and check the thermostat and the heating elements.

There is no current passing through these parts? Then you would have to replace the elements (you’ll find a step-by-step instruction below).
Read: How Many Amps Does Water Heater Use?
There Is Water on the Floor
The first thing that comes to mind is a leaking tank. Check the unit and fix the leak, if possible.
However, if water starts dripping right after you have performed a repair or installed the heater, one of the fittings might be loose.
Don’t forget to turn the power off and then check all the connections. Any wet pipe connections have to be tightened.
If everything in the unit is nice and snug but the problem remains, then there is something wrong with the relief valve.

- To check your theory, place a bucket right under the water relief valve and leave it there for some time. If you come back and there is water only in the bucket, then you’ve found the root cause.
- Make sure that your thermostat is not set higher than 120 F. Extremely high temperatures can cause the water to expand.
- If nothing helps, you would have to replace the valve.
How Do I Reset My Rheem Water Heater?
The majority of Rheem water heaters come with a thermostat and an element that makes sure that the temperature does not get too high.
If that does happen, the controller will break the power circuit. This is when you would have to reset the unit manually.
- Turn the power off.
- Remove the insulation and access panels, but don’t touch the protective cover on the thermostat.
- Push the red button.
- Put the panels back and turn the unit on.
Why Does My Rheem Water Heater Keep Shutting Off?
In a lot of cases, the issue with an electric water heater is pretty much straightforward – there is a lack of power.
But what about a gas water heater? What can make such a unit automatically shut off?
You will find this thing right next to the pilot light. In case it is dirty, turn the gas off, wait for the thermocouple to cool down, and then clean it with sandpaper.
- A damaged thermocouple
If this part of the unit is bent, you can, theoretically, try to rectify it, but the chances are high that you would have to call a professional to replace it.
- A dirty pilot tube
Is your flame weak and yellow? Then you should take a needle and gently remove any blockages from the pilot tube (don’t forget to let it cool down).
- A dirty air inlet
You might notice a screen at the bottom of your water heater. The job of the air inlet is to let enough air in the heater to keep the burners going.
However, if the screen is dirty, the air won’t be able to pass through it. Simply clean the thing and leave it to dry.
- Problems with the gas valve
If the valve is damaged, there will be no gas supply. Unfortunately, you will most likely have to replace the gas valve, if no advice mentioned above helped.
Is My Rheem Water Heater Overheating?
The most obvious sign that your water heater is overheating is extremely hot water.
Here are a few things that you can try to do if you have noticed such a problem:
- Adjust the thermostat lower. If this doesn’t help, you might have to replace the thermostat.
- Check the heating elements for mineral buildup. If the elements have such a coat, clean them.
- A pressure relief valve is the part of the unit that lets steam escape the system. If it is blocked, the water heater is going to overheat (it can be extremely dangerous).Turn the heater off and call a professional, especially, if you hear the water inside the tank boiling.
Read: Rheem Water Heater Error Codes
How to Replace a Heating Element or Thermostat?

Step 1
Turn off the water heater and shut off the water supply.
Step 2
If you want, you can drain the tank (this will help avoid any leaks).
Step 3
Take a photo of the wires and use a screwdriver to disconnect them.
Step 4
If you decided not to drain the tank, put some towels on the floor to keep everything dry.
Step 5
Use a wrench to loosen the element, pull it out, and then insert a new one. Tighten it with your hand and wrench, however, do make sure not to overtighten the connection.
Step 6
Consult the photo that you have taken to ensure that all the wires are in the right place.
What to Do If the Pilot Light Won’t Stay Lit?
Open the gas line valve, turn the knob to the ‘pilot’ position, and push it.
If you can’t hear a hissing sound, then the supply tube is blocked.
In case you can hear a sound, but the light just won’t stay lit, check the room for any drafts.
If this doesn’t help, make sure that nothing is blocking the vent and check the thermocouple.
Everything seems to be okay, but the flame isn’t able to stay lit? Then call a professional.
Read: Why Is My Propane Heater Not Working? 5 Common Reasons
To Sum Up
Always remember to follow the safety rules when troubleshooting your Rheem water heater.
In most cases, all you would have to do is adjust the thermostat and clean a few parts of the system. Some issues might require more complicated manipulations.
If you don’t really know what to do or feel like you are not the right fit for the job, the right (and safe) thing to do is to invite an expert over.
Read: How Much Does It Cost To Move A Furnace And Water Heater?