Rheem Water Heater Troubleshooting - Common Problems and Solutions

Published by 
Last updated: 
January 19, 2018

Rheem water heater troubleshooting allows you to find pressure relief valve to some common issues or indicates professional repair or replacement is needed. This guide to common water heater problems covers gas and electric models from Rheem, Ruud, and other brands.

Before taking the Rheem water heater pressure relief valve below, it’s worth remembering the potential dangers – burns from hot water or the tank, shock from electrical connections and the risk of a gas leak or carbon monoxide leak from gas models. Only take Rheem water heater troubleshooting steps you’re knowledgeable about and comfortable with. Calling a Rheem water repair technician is an affordable way to avoid serious injury.

rheem logo

Our Favorite Rheem Water Heaters

Rheem Water Heaters – Common Issues

Here’s a list of the most common Rheem water heater problems to look for. Solutions requiring multiple steps are found below.

No Hot Water

A tripped circuit breaker will shut down an electric heater and gas models that use electricity.

  • Gas: Check if the gas valve has been turned off. If you use propane, your tank might be empty. If the unit has a pilot light (see your manual), check to see if it is lit.
  • Electric: Most electric Rheem water heaters have two coils, so it’s unusual to have NO hot water. Check the circuit in the electrical box to make sure it hasn’t been tripped. If it is on, it’s possible the circuit breaker in the box has failed.

Not Enough Hot Water

If the water heater is new, or if you’ve just moved into a new home and aren’t familiar with the water heater’s capability, it’s likely that the unit is undersized. You're using hot water faster than it can make it. This problem is more common with electric models since they don’t heat water as quickly as gas models.

  • Gas: If the burner is firing, but you’re not getting enough hot water, the unit is too small, the gas valve is plugged with debris from age or the temperature is set too low.
  • Electric: If this is a new problem, then one of the two heating elements or thermostats is probably bad.
  • Mineral deposits: There’s another reason for this issue, and it applies where very hard water is being used. Mineral deposits build up in a tank, so that within three to five years, especially if the tank isn’t periodically drained, mineral buildup can reduce capacity by up to 15 gallons.

There’s Water on the Floor

The water could be coming from a leaking tank, more common in old water heaters, a loose fitting or normal discharge from the temperature pressure T&P relief valve.

Tools You'll Need for the Job

This small collection of items will assist you in Rheem water heater troubleshooting and possibly making a repair.

  • Your owner’s manual: There’s likely a section in the manual on Rheem water heater troubleshooting that will address the issue you’re having. If you don’t have the manual, you can probably find it online by searching the model name or number.
  • Flathead and Philips screwdrivers
  • Electrical tester
  • Pipe tape: Make sure it is for water and not gas.
  • Small plumber’s wrench
  • Bucket and towels
  • BBQ-style lighter
  • Heating element wrench (electric models only): An element wrench like this one can be purchased for $9-$15 at home improvement stores and online sellers.

Rheem Water Heater Troubleshooting

Here are tips for solving your Rheem water heater problem or deciding to call a Rheem service company to handle the repair.

No Hot Water

All electric water heaters and gas heaters that use electricity: The first issue to troubleshoot is a lack of power to the unit.

  • If the water from the hot tap goes cold, give a gas unit 15 minutes and an pressure relief valve 30 minutes to start making enough hot water for you to notice at the tap. However, if the water remains cold, it’s safe to say the unit isn’t heating water.
  • If the circuit breaker in your electrical panel is in the “Off” position, turn it to the “On” position. If it is midway between the two, it has been tripped. Turn it all the way to “Off”, and then turn it to the “On” position. If the circuit continues to trip, there’s an electrical issue that needs to be diagnosed and repaired by a qualified service technician.

Gas water heater: If your unit has a pilot light and it isn’t lit, follow the instructions in your user’s manual to relight the pilot using the BBQ lighter. If the unit has an electronic ignition and it won’t fire, the ignition might require replacing. Since replacing it involves the potential for a gas leak if not handled properly, consider calling a repair technician for the work.

Not Enough Hot Water

Gas water heater

If your gas water heater isn’t making enough hot water, try adjusting the thermostat to a higher setting. This might require a flat screwdriver placed in the slot on the adjuster. The manual has detailed instructions.

Caution: It’s recommended that you set the thermostat no higher than 120 degrees Fahrenheit to reduce the risk of severe burns from scalding. If the unit still doesn’t make enough hot water, it is either undersized for your needs, partially filled with mineral sediment or has a plugged gas valve. A Rheem technician can check the gas valve and clean or replace it.

Electric water heater

If you’re getting some hot water, and you can hear the unit heating, check the thermostat set point. Adjust it to a higher temperature, but no higher than 120F. If the water continues to be warm but not hot or heats very slowly, then one of the heating elements or thermostats is bad.

  • Use the electrical tester to test the heating elements and thermostats. Electrical current won’t pass through a bad part. Parts like this Rheem element and this Rheem thermostat are available online and at home improvement stores for less than $15. Titanium elements are available for about $50 if you want to reduce the chance of having to replace it again.

Replacing an Element/Thermostat

To replace an element or thermostat:

  • Turn off the double 240V circuit in the electrical panel for the water heater.
  • When replacing a heating element, shut off water leading to the water heater. Turn off the pump’s circuit, if you have a well and pump. Open a hot water faucet in a tub until the water stops flowing. This takes pressure off the water tank.
  • Remove the part from its packaging. Do the same with the wrench when replacing a heating element.
  • Use a screwdriver to disconnect the wires to the bad element or thermostat.
  • Place a couple towels on the floor if replacing an element. Quickly loosen the element with the wrench first and then with your hand. Pull it out quickly, insert the new element, and hand-tighten it. Then, use the wrench to tighten it until there are no leaks. Be careful not to overtighten it.
  • If replacing the thermostat, take a digital picture of the thermostat’s wiring before removing the wiring and the bad part. Install the new thermostat. Check the picture to ensure proper wiring.

Note: If you’d prefer not to have a small amount of water leak from the tank while replacing the element, drain the tank first by attaching a garden hose to the threaded spigot near the bottom of the tank, running the hose to a floor drain or to the outside of your home and turning on the spigot.

There’s Water on the Floor

If this problem starts immediately after you install or repair a water heater, a fitting is probably loose. Turn off power to the unit, if applicable, and check all pipe connections for water. Gently tighten any wet connection. The connection should have pipe tape on it and be very snug, not overly tight. If you replaced an electric element, remove the cover to it, and check/tighten the element if necessary.

In Case Everything Is Set

If everything is tight, the next step is to determine if the relief valve releases water.

  • Place a bucket on the floor beneath the valve or hang a light bucket from it, and if there is only water in the bucket the next time it leaks, you’ve found the source.
  • If the thermostat is set above 120F, turn it down to that temperature or lower. Having the thermostat set too high will cause water expansion and force water out the valve.

If Water Is Still Dripping

If water continues to drip or flow from the temperature/pressure relief valve, you can replace it with the following steps:

  • Purchase the right valve for your model. Your manual should have a parts list in it, or you can find one online. Common Rheem T&P valves like this one cost less than $20.
  • Turn off power and water to the unit, and turn off the well pump, if applicable.
  • Either run hot water at a tap for a few minutes or through a hose attached to the drain near the bottom of the tank. This should lower the water level to below the valve location.
  • Flip open the relief valve to take any remaining pressure off the tank.
  • Using a wrench, loosen the old valve by turning left/counter-clockwise.
  • Wrap pipe tape clockwise around the new valve’s threads, and install it, tightening by hand until snug.
  • Use the wrench to continue tightening it one-quarter to one-half of a turn
  • Turn the power and water back on. Allow the water to heat up. If the valve leaks because it is too loose, tighten it another quarter to half a turn.

If water isn’t coming from a fitting or the T&P relief valve, the tank is leaking. It’s probably time for a new water heater.

Caution Notes

We’ve included several safety steps in this Rheem water heater troubleshooting guide to prevent burn and shock. Here are additional warnings:

  • If you smell gas around a gas water heater, turn off the gas valve and don’t ignite anything. Evacuate your home, and call a repair technician or the gas company.
  • Since deadly carbon monoxide (CO) is a byproduct of the combustion of natural gas and propane, it is important to install a CO detector near a gas water heater. If the carbon monoxide detector goes off, evacuate the area. Call 911 or a service technician immediately.

Rheem Water Heater Troubleshooting Summary

If you didn't find the issue you’re having here or these steps don’t solve it, a service technician can help. They can evaluate whether you can repair or replace your water heater. Replacement makes sense if the unit is 7+ years old and the repair is a costly one. Finally, if you managed to solve your issue, sharing these Rheem water heater troubleshooting tips on social media might benefit others. They apply to any brand water heater.

All Things HVAC

We formed this web site so consumers could have an educational place to go for good, solid information.  We are not trying to sell you anything.
Copyright © 2023 AllThingsHVAC. All Rights Reserved