Honeywell Water Heater Status Light Blinking Blue [Solved]

Honeywell is highly known for producing high-quality water heaters with long durability and longevity. But while operating, owners often face some warning in the heater action as an error code. These error codes are specified by different colored lights flashing at a different number of times.

Same as, Honeywell water heater status light blinking blue 3/6/8 or 8 times points out several malfunctions from the heater. The leading reasons for flashing blue light include malfunctioning of the pressure switch, water leakage, a kinked vacuum tube attached to the pressure switch, or a faulty flammable vapor sensor. 

Anyway, you need to interpret the different blinking light codes to erase these codes from the heater. Read out our comprehensive discussion to know the details about each code with the corresponding solutions.

honeywell water heater status light blinking blue

Honeywell Water Heater Status Light Blinking Blue [Solved]

Let’s have a glimpse at the blinking blue light on the water heater at a different number of times:

  • Blue light blinking 3 times: Open draft pressure switch.
  • Blue light blinking 6 times: Water leakage in the water heater.
  • Blue light blinking 7 times: Flammable vapor sensor error.
  • Blue light blinking 8 times: Flammable vapor sensor out of specification. 

However, this troubleshooting guide will clarify all reasons that cause the heater to flash blue light. So, stay connected with us till the end.

Note: You can also read how to fix Honeywell hot water heater with no status light problem.

1. Honeywell Water Heater Status Light Blinking Blue 3 Times

Honeywell water heater flashing blue light 3 times is the error indication of an open draft pressure switch of the heater. The draft pressure switch of the furnace is a safety component that is connected with the draft motor through a hose.

 When it senses negative pressure from the draft inducer motor, it goes to the CLOSED position. Then, the combustion gasses will move out through the vents and start ignition again.

Anyway, if anyhow, the pressure switch fails to sense the negative pressure, it will be stuck open, and the furnace wouldn’t be vented. Then the heater catches the 3 blinking error codes from the status light. Note down the related responsive factors for stuck open draft pressure switch:

  • Blocked exhaust vent or air intake
  • Weak inducer fan
  • Failure of the inducer fan motor
  • Clogged condensate drainage system
  • Blocked or detached pressure switch hose
  • Low resistance through the pressure switch
  • Broken pressure switch


  • In the first step, you have to find out the blockage of the air intake vent and exhaust vent. Clean out the vents properly and the vents cap as well. Make sure you have turned off the power of the furnace before cleaning.
  • Now, remove the panel of the heater in order to gain access to the inducer fan assembly.
  • Clean the stuck debris of the fan and fan motor.
  • Ensure all the screws of the inducer fan assembly are tightened.
  • Check out all the wiring connections to the control board.
  • Measure the voltage reading of the motor. In the case of lower voltage, you need to replace the control board and fan assembly.
  • Clean the condensate drain. Check out the drain valve and clean it as well.
  • Besides, look for a kinked vacuum tube attached to the pressure switch. Replace the cracked one. 
vacuum tube of the pressure switch
  • Finally, measure the voltage of the pressure switch. A good pressure switch should give a 0 to 0.1 reading. If not, be sure it is the culprit and needs to replace.
  • Now, the blinking error issue should be resolved.

2. Honeywell Water Heater Status Light Blinking Blue 6 Times

Honeywell water heater flashing blue light 6 times is the error indicating water leakage in the water heater. There are several reasons that are responsible for leaking water out of the water heater. 

When you find out that the water heater is leaking, you need to take action immediately. But before that, let’s know the responsive factors for water leakage on the water heater.

  • Long-wearing and tearing
  • Loosen or opened the drain valve
  • Faulty temperature and pressure relief valve
  • High water pressure
  • Loosen inlet or outlet connection
  • Sediment collection at water tank bottom
  • Cracked storage tank
  • A deteriorate gasket

 Follow the below guide to resolve the leaking issue from the water heater.


  • First of all, you have to detect the source of the problem. Look closely at the heater exterior and find out from where moisture is developing.
  • Once you have found the leakage source, your next step will be shutting down the heater. 
  • Shut off the gas shut-off valve as well, and stop the flow of the cold water supply into your water heater.
  • Now, depending on the severity of the leakage, you will have to fix it.
  • If the water is appearing from the connection points of the cold water inlet and hot water outlet pipes, take a pipe wrench to secure the connections.
  • Now, in the case of sediment build-up at the tank bottom, flush and clean the tank. 
  • Slowly tighten the loosened drain valve using a pipe wrench. Replace the defective valve.
leaking water heater drain valve
  • If you suspect the leak is due to a worn gasket, faulty pressure relief valve, or cracked tank, you need to contact a plumber to replace the defective part.
  • Also, discuss with them to determine what’s causing excess pressure inside the tank.

3. Honeywell Water Heater Status Light Blinking Blue 7 Times

Blue light flashing in the water heater 7 times every 3 seconds means flammable vapor sensor error. Here the flammable vapor sensor of the water heater goes into lockout mode. 

Flammable vapor sensors are safety devices that lead the heater to the safety lockout mode. In this soft lockout, the heater and pilot light shut down when flammable vapors are detected near the unit.

 By this, the sensors help to prevent the possibility of unsafe ignition. The sensor functions by changing resistance when it detects flammable vapors near this passive safety device. 

Anyway, after a sudden changing of the resistance from the designated range, the control panel of the heater senses this and won’t let the heater fire up and flashes blue light 7 times as an error indication.

The FVS will get tripped by placing paints, mopping the floor with bleach, or by noticing seemingly harmless events in very close proximity to the heater. When the heater is in a soft lockout mode, it will not operate again until the sensor is reset or replaced. 

Now, if you are confused about how you reset the FVS lockout to turn back on the heater, follow the below instructions:

How To Reset Flammable Vapor Sensor Lockout In Water Heater

  • The first thing is that you have to shut down the heater. Then, unplug the heater from the power connection.
  • By this, the flickering from the blue light will stop.
  • Leave the heater unplugged for about 10-20 seconds, and then plug it back again.
  • Now flip the pilot light knob from Low to High and then turn the knob from High to Low again. Repeat this attempt about 6 times or until you will hear a click sound.
flipping pilot light knob from low to high
  • The status light blocking will be clear, and the heater will start to operate again. 
  • In many cases, you need to replace the FVS. Contact any certified plumber to do this.

4. Honeywell Water Heater Status Light Blinking Blue 8 Times

Flashing a blue light 8 times on the Honeywell water heater indicates that the Flammable Vapor Sensor is Out of Specification. This error is most likely related to a bad thermostat or flammable sensor. 

Either the FVS has been disconnected or defective. Sometimes it results in a lockout or a reset problem of the water heater. This could happen due to gasoline or other flammable gas being detected by the sensor, lower voltage supply, or faulty wiring from the sensor. 

By this, the water heater will not be able to either start or work at all. Follow the below instructions to erase the 8 times blinking issue from the heater.


  • First, if there is gasoline or other flammable gas nearby from the heater, the sensor will go to soft lockout. Reset the FVS correctly. We have already discussed the needed methods for this.  
  • Now, locate the flammable vapor sensor of your heater. You will find the sensor near the bottom of your unit.
  • Then, pull the flammable vapor sensor from its bracket on the base ring of the heater.
  • You will find two wires attached to the FVS.
  • Carefully detach both wires.
  • Now, take a multi-meter and go ahead to measure the voltage reading of the sensor.
  • Place the lead between the two terminals on the sensor.
  • There should be 7000 to 25,000 Ohms as good FVS.
  • If not, replace the defective FVS and the faulty wiring.
  • The blinking issue should be resolved.


What does a blinking white light mean on a water heater?

The blinking white light on the water heater tells you that your unit’s pilot light is out. Also, there may have a thermocouple issue or malfunctions from the water heater tank. The faulty electrical connection is also highly responsive to this.

What does a blinking yellow light mean on a water heater?

When there is inadequate combustion air throughout the unit, the heater starts blinking yellow on the status light. Leaking pipes, worn-out gas valves, clogged exhausts, and damaged temperature/pressure valves are the leading reasons for this.

Wrapping Words:

Since we have reached the end of this guide, hopefully, now you know every flashing blue light code on the honey well water heater. Each solving point is enough to resolve the related error codes efficiently.

If still, you have any questions and queries on the above-discussed factors, don’t hesitate to let us know through comments. We will reach out to you with the best solutions as soon as well.

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