14th Oct 2026
Norcold N4000 Error Code 3 (Gas Lockout: No Flame in 30 Seconds)
CODE 3
Norcold N4000 Error Code 3 (Gas Lockout: No Flame in 30 Seconds)
The burner didn’t light within 30 seconds, so the fridge locked out gas. If the flame lit and then went out during the same cycle, it tries 3 times before locking out.
Before you start
- Where things are. The power board, fuses, burner and heaters are behind the lower outside vent on the back of the fridge. The control panel is on the front, at the top.
- Good gas pressure is 10.5 to 11.5 inches water column.
- Safety first. Let the burner cool before working on it. Never use a flame to check for leaks.
Fits these models
The Norcold N4000 series, built by Thetford. 3-way (12V DC, 120V AC and propane).
How to read this code
LED panel: press the ‹, □ and › buttons together until the temperature bars change. The lit bars spell the code in binary. This pattern is code 3.
LCD panel: the code number shows next to the wrench symbol.
No 12 volts, no code: the controls need 12V DC to show any error. With 12V, the blue power light is on.
STEP 1
Check the gas supply
Make sure the tank isn’t empty and every gas valve between it and the fridge is open.
Is gas reaching the fridge?
Fix the gas supply
Fill the tank, open the valves, then turn the fridge off and on.
STEP 2
Look for a spark
Turn the fridge off and on and watch the electrode while it tries to light.
Is there a spark?
STEP 3
Check the gas valve
There’s a spark but no flame.
Is the gas valve opening?
STEP 4
Check the electrode gap
Measure the gap between the electrode tip and the burner.
Is it about 4 mm (5/32 inch)?
Adjust the gap
Set it to about 4 mm, then try again.
STEP 5
Check the electrode and its connections
Look at the electrode, its cable and connections for damage or a loose fit.
Are they OK?
Repair or replace
Repair the connection, then turn the fridge off and on. If the electrode is damaged or code 3 comes back, replace the electrode.
STEP 6
Check the burner and flame
Look at the burner jet (injector) and, if it lights, the flame.
Is the injector clean and the flame dense and blue?
Clean the burner
Clean the burner and injector. Replace the burner if combustion is still poor.
STEP 7
Check the gas pressure
Measure the gas pressure at the fridge.
Is it 10.5 to 11.5 inches water column?
Check the gas installation
The RV’s regulator or gas lines aren’t delivering the right pressure.
Replace the power board
Gas, spark and burner are all good. Replace the power board. Match the part number on your old board; see the N4150, N4141 or N4104 parts or ask a tech.
Still stuck? ask a tech with your model, serial number and the code you’re seeing. We’ll confirm the part before you order.
Covers the Norcold N4104, N4141 and N4150. Based on Thetford’s N4000 troubleshooting guide (Error code 3), with North American voltage and gas pressure values.