Rheem Water Heater 8-1 Flashes: Meaning and Fix
Applies to: Rheem ProClassic power direct vent gas water heaters (natural or LP) with a flue damper, per the Gas Valve LED Codes table in the Use and Care manual; other Rheem and Ruud water heater lines can use different codes.
Also shown as: Eight-One Flashes, 8 1 Flashes
Reading the water heater display
A gas tank water heater reports its fault as a count of LED flashes on the gas control valve, seen through the small window or viewport near the base of the tank. Count the flashes, note the pause (usually three seconds) and watch a second full round before you decide which code it is. Some controls use two groups, such as six flashes then one.
Rheem makes gas furnaces, tank water heaters and tankless water heaters, and each line reports faults differently: status LED flash counts on furnaces and tank gas controls, numeric codes on tankless units. Use the table for the product family on your rating plate. Check the model label on your unit before using any chart.
What causes 8-1 Flashes
- Flammable vapor sensor values out of range
- Improper sensor wiring or connection
- Faulty flammable vapor sensor
How to fix it
If you smell gas, leave the building and call your gas utility from outside; do not touch switches or the unit. Switch the water heater off and let it cool before you touch any internal part, and call a licensed plumber or water heater technician if you are not sure.
The code meaning comes from the manufacturer document listed under Sources. The causes and steps below are general troubleshooting guidance, not the manufacturer's service procedure.
- Turn the gas control knob to OFF. If you smell gas, leave the building and call your gas utility from outside; do not touch switches.
- Have a technician inspect the flammable vapor sensor wiring and connections.
- Replace the flammable vapor sensor if the reading is out of range.
- Replace the gas control if the fault remains.
- If the code returns after these checks, call a licensed plumber or water heater technician and give them the flash count and the model number from the rating plate.
Questions
What does Rheem water heater 8-1 Flashes mean?
8-1 Flashes on a Rheem gas storage water heater with an LED on the gas control means the system is in lockout because it detected a flammable vapor sensor fault. The manual lists sensor values out of range, bad sensor wiring or connections, or a faulty sensor. The Rheem manual lists this under Gas Valve LED Codes.
Can I reset the water heater myself?
Turning the gas control knob to OFF, waiting, and relighting it clears some codes. If the same flash count comes back, the fault is still there and the unit will lock out again. Do not bypass a safety device to keep it running.
When should I call a technician?
Call a licensed plumber or water heater technician for anything involving gas, venting, the pilot, the gas control or flammable vapor sensor, or when the code keeps returning after the simple checks.
Other Rheem water heater codes
Sources
Part numbers are OEM references; confirm fit by your model number before ordering. Meanings compiled from manufacturer and parts-retailer documentation; see sources below. Unplug the appliance before opening it.