A.O. Smith fault code F04
Fault code F04 on an A.O. Smith water heater (including ADMR) means: Three unsuccessful ignition attempts: No gas. Reset the appliance once. If the code comes back, a part is usually faulty. You can check the water pressure and settings yourself; leave work on gas-carrying parts to a certified gas engineer.
After a safety alert (gas, flue gas, combustion), reset no more than once and call in a certified gas engineer. If you smell gas, call your national gas emergency number or 112 immediately.
Cause
Fault code F04 on an A.O. Smith water heater indicates: Three unsuccessful ignition attempts: No gas.
Applies to
A.O. Smith ADMR, 115, 135, 40, 50, 60, 80, 90.
Fault code F04 on other A.O. Smith series
The same code does not mean the same thing on every series. Check the rating plate to see which series you have:
- F04 on ADMR, 115, 135, 40, 50, 60: Three unsuccessful ignition attempts: Air in the gas pipe.
- F04 on ADMR, 115, 135, 40, 50, 60: Three unsuccessful ignition attempts: No burner pressure.
- F04 on ADMR, 115, 135, 40, 50, 60: Three unsuccessful ignition attempts: Fault in the hot surface igniter circuit.
- F04 on ADMR, 115, 135, 40, 50, 60: Three unsuccessful ignition attempts: Fault in the ionisation circuit.
- F04 on ADMR, 115, 135, 40, 50, 60: Three unsuccessful ignition attempts: Supply voltage too low.
- F04 on BFC, 100, 120, 28, 30, 50: Three failed ignition attempts: No gas.
- F04 on BFC, 100, 120, 28, 30, 50: Three failed ignition attempts: Air in the gas pipe.
- F04 on BFC, 100, 120, 28, 30, 50: Three failed ignition attempts: Fault in the hot surface igniter circuit.
- F04 on BFC, 100, 120, 28, 30, 50: Three failed ignition attempts: Fault in the ionisation circuit.
- F04 on BFC, 100, 120, 28, 30, 50: Three failed ignition attempts: Supply voltage too low.
- F04 on Innovo, IR 12-160, IR 12-200, IR 20-160, IR 20-200, IR 24-245: Ignition fault: No gas.
- F04 on Innovo, IR 12-160, IR 12-200, IR 20-160, IR 20-200, IR 24-245: Ignition fault: Air in the gas pipes.
- F04 on Innovo, IR 12-160, IR 12-200, IR 20-160, IR 20-200, IR 24-245: Ignition fault: Defective glow plug circuit.
- F04 on Innovo, IR 12-160, IR 12-200, IR 20-160, IR 20-200, IR 24-245: Ignition fault: Fault in ionisation circuit.
- F04 on Innovo, IR 12-160, IR 12-200, IR 20-160, IR 20-200, IR 24-245: Ignition fault: Supply voltage too low.
- F04 on Innovo, IR 12-160, IR 12-200, IR 20-160, IR 20-200, IR 24-245: Ignition fault: The bent ionisation probe is touching a metal surface.
- F04 on Innovo, IR 12-160, IR 12-200, IR 20-160, IR 20-200, IR 24-245: Ignition fault: The ceramic part of the ionisation probe is broken or cracked.
Matching parts
A.O. Smith parts are available from Instalpunt; shipping to EU countries from €17.95 (€24.95 for more distant countries), usually 3–5 working days.
For fault code F04, the part involved is usually in the category: burner.
This message does not point directly to one faulty part. These are the parts that most often fit this appliance:
- A.O. Smith anode 3/4" € 47.04
- A.O. Smith service gasket manhole € 56.19
- A.O. Smith sensor NTC assy € 57.50
Fix it yourself or call an engineer?
Always consult the manual for your appliance and work safely. If in doubt or if the fault comes back, call in a qualified professional. A question about a part? Write to us at info@instalpunt.nl.
Frequently asked questions
What does A.O. Smith water heater fault code F04 mean?
Three unsuccessful ignition attempts: No gas.
How do I fix fault code F04 on an A.O. Smith water heater?
First check the cause described above. Then restart the appliance using the reset button. If the message comes back, a part usually needs replacing or the fault needs to be repaired by a qualified professional.
Which parts do I need for A.O. Smith fault code F04?
That depends on the exact cause. In the A.O. Smith parts overview at Instalpunt you will find the current price and stock for each part.
Can I fix fault code F04 myself?
You can reset the appliance and check things like the water pressure or settings yourself. Work on gas-carrying parts must be left to a certified gas engineer.
All A.O. Smith water heater faults and codes at a glance →