On the covered Rheem PowerVent water heater, display 89 and eight-two flashes means a temperature sensor fault was detected. First, note the code and the model number. Then: Rheem's bulletin lists this as a temperature sensor fault. Sensor work belongs to a technician.
Differential
Likely causes of “Rheem PowerVent water heater display 89 and eight-two flashes”, and how to tell them apart
- 1
A temperature sensor fault was detected
What separates it The status light flashes eight times and then two times
How to confirm Note the code and the model number
- 2
A sensor that has failed
What separates it The sensor reads out of range
How to confirm A technician tests the sensor
- 3
A damaged or loose sensor wire
What separates it The wire is chafed or unplugged
How to confirm A technician checks the harness
- 4
A sensor that is not in contact with the tank
What separates it The sensor has slipped out of its well
How to confirm A technician refits it
- 5
A control board fault
What separates it The sensor tests well
How to confirm A technician checks the control
Before you touch a setting
Record this first — changing settings destroys the evidence
- That the pattern is eight flashes followed by two
- Whether the water is hot, cold or inconsistent
- The model number
- How long the code has shown
Try in this order
0 of 9 completedWhat to do first
ReversibleNote the code and the model number.
Correct only the documented fault domain
ReversibleRheem's bulletin lists this as a temperature sensor fault. Sensor work belongs to a technician.
Count the flashes
ReversibleThe pattern is a group of eight flashes, a pause and then two flashes. Write it down.
Note the model number
ReversibleThe correct sensor depends on the model, so record it from the label.
Check the water temperature
ReversibleRun a hot tap and see whether the water is hot, cold or varies.
Do not touch the gas controls
ReversibleLeave the gas valve and the sensor to a technician.
Call a technician
ReversibleSensor work belongs to a technician.
Ask for a sensor test
ReversibleThe technician measures the sensor and its wiring before replacing any part.
Describe the symptoms
ReversibleTell the technician whether the water has been too hot, too cold or has changed with use, since that helps them to confirm that the sensor is the cause.
Model-specific
What is true of this model and not of its siblings
- The code on this page
- Code 89, eight then two flashes: temperature sensor fault.
- Parts involved
- The temperature sensor and its wiring.
- Rheem's guidance
- Sensor work belongs to a technician.
- What the sensor does
- The temperature sensor tells the control how hot the water is, so that the control can open and close the gas valve to hold your setting. If the sensor fails, the control has no way to know whether the water is cold or dangerously hot, so it stops the heater to be safe.
- Symptoms before the code
- A failing sensor can make the water temperature swing, with bursts of very hot and very cold water before the control reports the code. Telling the technician about these swings helps them to confirm the sensor as the cause.
Stop boundary
When this stops being a self-service repair
- !Rheem's bulletin lists this as a temperature sensor fault, and sensor work belongs to a technician
- !Do not bypass a temperature sensor
- !If you smell gas, leave the house and call the gas company
Evidence ledger
Sources behind this answer
Exact questions
Common questions
What does display 89 and eight-two flashes mean on a Rheem PowerVent water heater?+
A temperature sensor fault was detected.
Does the heater still heat?+
It may not, or it may behave unpredictably.
Can I replace the sensor?+
A technician should, since it is part of the safety system.
Is it expensive?+
A sensor is usually a modest part.
What if I ignore it?+
The control may lock out, and you would lose hot water.
Does the water get dangerously hot with a sensor fault?+
The control shuts the heater down before that happens, but the water in the tank may still be hot, so use care.
Is the sensor easy to replace?+
For a technician, yes, though it needs the tank to be drained in some designs.