Why is My Rheem Water Heater Status Light Blinking Blue?

By - Rajib Ahmed

Updated -

Rheem produces top-quality water heaters, among the most reliable ones in the HVAC industry. These heaters not only heat water fast but also include a warning system.

This warning system aids in monitoring and maintaining the unit. For instance, a blinking blue light indicates something is wrong with the heater.

Here are the problems with your Rheem water heater when it flashes blue light.

Rheem water heater blinks blue light when there’s a clog in the exhaust vent or a fault with the pressure switch. Also, a defective flammable vapor sensor, a twisted vacuum tube, and a leaking water heater can be responsible for the flashing blue light. You should attend to this warning light to prevent complications.

In this post, I’ll discuss the faults leading to the Rheem water heater’s status blinking blue and the troubleshooting steps.

Why Does My Rheem Water Heater Status Blink Blue?

Why is My Rheem Water Heater Status Blinking Blue

Your Rheem water heater status will blink blue to indicate a fault with the appliance.

Although this appliance is one of the best on the market, like every other home appliance, it can develop a fault with frequent usage.

For example, a flashing blue light indicates a problem with the pressure switch, vacuum tube, or vapor sensor.

Additionally, the blue light flashes several times to point at a particular fault with the appliance. For instance, if the blue light flashes three times, it signals a fault with the pressure switch.

Below are what you should know when you see a blinking blue light on your Rheem water heater:

#1. Problems with the Exhaust Vent

The exhaust vent is a vital part of the Rheem gas water heater, with an in-built fan that pushes the exhaust gasses through the outlet.

This part is critical for maintaining the integrity of your water heater, as it prevents gases from accumulating in the unit.

Faults with the exhaust vent can occur when dust, debris, or spillage blocks the outlet, preventing the unwanted gasses from escaping.

When this happens, the Rheem water flashes blue light three times.

#2. Twisted Vacuum Tube

A vacuum tube attaches to the pressure switch on top of your heater. Once this tube gets kinked or twisted, the heater flashes blue light to signal you.

#3. Problems with the Flammable Vapor Sensor

The Rheem water heater’s flammable vapor sensor (FVS) is a safety part that detects flammable vapor in the appliance.

When combustible vapors concentrate intensely in the heater, the FVS shuts off the gas valve to prevent an explosion.

A blue light in your heater status flickers seven times when this part stops functioning.

In addition, when this sensor goes out of specification, the heating system flashes blue light eight times.

The FVS can stop functioning due to physical damage. However, other factors can lead to its malfunction.

Below are some of the things that trigger a fault in the FVS:

  • For example, placing your unit near a cleaning agent or a laundry room can trigger the FVS into lockout mode.
  • Placing hydrocarbon solvents close to your heater can set it off. This solvent is very volatile and can ignite quickly.
  • Dirt or soot accumulation in the arrestor screen of the FVS can trigger it.
  • The sensor will trip off if the combustion chamber’s temperature increases against the required thermal rating (320°F–392°F).

#4. Problem with Pressure Switch

The pressure switch is on top of your water heater. The heater status will flicker blue light three times once this part is faulty. 

A high voltage, the exhaust vent, and the vacuum tube can cause a fault in the pressure switch.

#5. Leaking Water Heater

Your Rheem water heater will also blink blue light when it’s leaking. In this case, the blue light flashes six times. Several factors can lead to your system leaking water.

Below are some of them:

  • Excessive water pressure.
  • Damage in the internal tank.
  • Rusted T&P valve.

How Do I Fix Rheem Water Heater with Its Status Blinking?

Fixing your Rheem water heater isn’t difficult. But first, you’d have to inspect the parts for damages according to the number of times the blue light flashes.

Below are ways to fix a faulty Rheem water heater blinking blue: 

#1. Fixing the Exhaust Vent

If the heater status flickers blue light thrice, the exhaust vent is one of the parts to check for faults. 

To inspect the exhaust vent, do the following:

  • First, start and run your heater for several minutes.
  • Next, light a match and put it off, then hold it close to the base of the vent pipe.
  • You should see the smoke travel towards the flue; It shows the vent is venting gasses properly.
  • The smoke won’t go into the vent pipe if the vent is clogged.
  • To fix a blocked vent, first, turn off the heater. Then unscrew the vent and keep it joined to the hood. Then clean off every visible dirt and debris.

#2. Fixing a Kinked Vacuum Tube

If you notice the vacuum line is kinked, you only have to straighten it. However, you’d need to replace the tube if you notice a crack instead.

#3. Fixing the Pressure Switch

The pressure switch could also be faulty when the blue light flashes three times.

First, you’d have to test the switch for the reading. Use an ohmmeter to take the reading. It isn’t very accurate if it reads anything above 0-0.1. You’d need to replace the pressure switch.

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Here is how to replace the pressure switch of your Rheem heater:

  • First, unplug your unit from the power socket.
  • Next, remove the upper panel from the heater.
  • Next, remove the vacuum line from the pressure switch and disconnect the wires.
  • Next, use a flathead screwdriver and unscrew and remove the pressure switch.
  • Then, install the new pressure switch, positioning it under the frame and screwing it properly to secure it in place.
  • Next, connect the vacuum tube and all wires appropriately.
  • Finally, place the panel in place.

#4. Fixing the Flammable Vapor Sensor

The flammable vapor sensor is faulty when your heater blinks blue light 7 or 8 times. The first step in fixing this sensor is to reset it.

Below is the step in resetting the FVS:

  • First, locate the gas valve. Most heaters come with a Honeywell gas valve.
  • Next, disconnect the water heater from the power supply and plug it back after 10 seconds.
  • Then, hold the pilot knob of the gas valve switch and change it from the “Vacation” setting to the extreme “Hot” setting.
  • Repeat this step 5-6 times to reset the sensor successfully.

If, after resetting the FVS and the blue light keeps flashing 7 or 8 times, you’d have to replace the sensor.

Below are the steps to replace the FVS:

  • First, locate the FVS under your unit. You’ll find a bracket; remove the cover. Then, use a screwdriver to unscrew and pull out the FVS carefully.
  • Measure the reading with a multimeter. It should be between 7,000-25,000 ohms. 
  • If it’s below 7,000 ohms, then it needs replacement.
  • Fix the new FVS by screwing it in place and connecting the cables appropriately.

Furthermore, note not to place the heater close to any agent that can trigger off the flammable sensor. 

In addition, ensure the combustion chamber’s temperature is within the standard thermal rating.

#5. Fixing a Leaking Water Heater

When your heater status blinks blue light six times, your heater is leaking water. Various faults cause a leaking water heater.

First, you should locate the source of the leak to enable you to fix the leak.

Six Common Reasons Rheem Water Heater Blinks Codes

There are various reasons Rheem water heater blink codes. Usually, when there’s a fault with the heater, it blinks various codes to help identify the fault.

These could be flashing light codes, or you’d see the error code on the Led display panel in front of the heater.

Below is a table showing some of the reasons Rheem water heater blinks codes and their code numbers:

Reasons Rheem Heater Blinks CodesError Codes
The heater running for too long leads to one-hour continuous combustion00
Improper communication with remote control76
The temperature of the water is above the thermostat settings16
No ignition11
No flame12
Improper thermistor connection35

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