On the covered AO Smith gas water heater, 7 flashes means internal control failure, which A. O. Smith lists when the gas control finds a fault in its own electronics. First, look for moisture or scorch marks around the control, and write down the seven-flash pattern.
Differential
Likely causes of “AO Smith gas water heater code 7 flashes”, and how to tell them apart
- 1
An internal fault in the gas control's electronics
What separates it Seven flashes and no heating
How to confirm A. O. Smith words seven flashes as an internal control failure
- 2
A power surge or a storm that damaged the control
What separates it The heater failed after lightning
How to confirm Check the home's other electronics and tell the technician
- 3
A control damaged by a flood or moisture
What separates it Water near the base of the heater
How to confirm Technician inspection of the area
- 4
Repeated relighting that wore the control
What separates it The heater was reset many times
How to confirm Stop relighting and call
- 5
A heater that is new and defective
What separates it The code appears early
How to confirm Warranty claim
Before you touch a setting
Record this first — changing settings destroys the evidence
- That the status light flashes seven times
- Whether a storm or a power cut came first
- Whether there is moisture near the heater
- The model, serial number and date on the label
Try in this order
0 of 8 completedWhat to do first
ReversibleLook for moisture or scorch marks around the control, and write down the seven-flash pattern.
Correct only the documented fault domain
ReversibleA. O. Smith's steps for seven flashes: put the gas control thermostat knob in the OFF position, shut off the main gas supply, and arrange for the gas control valve and thermostat to be replaced.
Count the flashes
ReversibleSeven, then a pause.
Turn the knob to OFF
ReversibleAnd shut the gas valve.
Look around the heater
ReversibleFor moisture or scorching.
Photograph the label
ReversibleFor the order.
Do not relight over and over
ReversibleThe control has failed.
Book a licensed technician
ReversibleTo fit a new control.
Model-specific
What is true of this model and not of its siblings
- A control with its own brain
- On this type of heater the gas valve, the thermostat and the safety logic live in one assembly. The assembly checks itself. Seven flashes means the self-check found a fault in the assembly's own electronics, which is why no amount of adjusting helps.
- Do not keep relighting
- Pressing the ignition again and again does not mend a failed control and keeps gas flowing to a heater that cannot control it. A. O. Smith's steps start with the knob and the gas supply off.
- Surge and moisture
- Control electronics are sensitive. A lightning surge, or a leak that dripped on the control, are two events a technician asks about, since they affect warranty and whether to check the rest of the heater.
- The part and its cost
- The control is a major part. A. O. Smith's guidance is to replace the whole valve and thermostat. Ask for the part price and labor in writing and compare with the cost of a new heater if yours is old.
- Hot water meanwhile
- Plan for several days. Use a kettle and the stove.
- Gas safety
- If you smell gas, leave first and call the utility.
Stop boundary
When this stops being a self-service repair
- !Turn the gas control knob to OFF and the main gas supply OFF before any repair
- !If you smell gas, leave the building and call the gas utility from outside
- !Call a licensed plumber or gas technician; replacing a gas control is not owner work
Evidence ledger
Sources behind this answer
Exact questions
Common questions
What does 7 flashes mean on a AO Smith gas water heater?+
Internal control failure, which A. O. Smith lists when the gas control finds a fault in its own electronics.
What do seven flashes mean on an A. O. Smith gas water heater?+
An internal control failure.
Can a storm cause it?+
A surge can damage the electronics.
How is it repaired?+
By replacing the gas control valve and thermostat.
Is it covered by warranty?+
Check the date on the label.