Rational Combi Oven Error Code Service 140.4: Gas Warning Level 1-2
Service 140.4 on a gas SelfCookingCenter (Index H and I), iCombi Pro or iCombi Classic is warning level 1 and 2 of the gas combustion system. It follows several gas resets in a row, or a short at the ignition electrode lasting 60 seconds or more. Close the gas valve if it keeps returning and call us early, before cooking is blocked.
High: a gas combustion warning that leads to a cooking lockout if it continues.
- Code
- Service 140.4
- Maker
- Rational
- Equipment
- Combi ovens
- Applies to
- SelfCookingCenter (Index H/I, SCC-07-00-10.6.34+), iCombi Pro (Index J, LM100-16.3.28+), iCombi Classic (Index J, LM200-8.0.0+)
What does Rational error code Service 140.4 mean?
Updated software on gas Rational ovens keeps a history of gas resets and watches the ignition electrode. Service 140.4 is the first warning stage of that system. It appears after several gas resets in a row, or when the ignition electrode shows a short lasting 60 seconds or more. Each earlier reset has been the control retrying a gas start, so the message tells you the oven has been struggling with combustion, not just once. If the problem stays, the oven blocks cooking, which is why the maker's advice is to call early. The listed causes are the ignition electrode and its short to ground, the gas valve and automatic ignition controller, gas supply pressure and connection, and the history of recent gas resets stored in the oven. That last item matters because the oven counts resets, so pressing reset repeatedly pushes you toward the lockout. This stage is a warning, and the oven may still cook, but the same causes that trigger it are the ones that lead to Service 140.8.
Affected models and control systems
This applies to gas SelfCookingCenter (Index H/I, SCC-07-00-10.6.34 and later), iCombi Pro (Index J, LM100-16.3.28 and later) and iCombi Classic (Index J, LM200-8.0.0 and later), per Technical Information TI_2220.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- Service 140.4 on the screen
- Gas resets happening several times in a row
- A burner that starts with difficulty
- Cooking still possible but with warnings
Possible causes
Listed in Rational's documentation
- Ignition electrode shorted to ground
- Gas valve or automatic ignition controller
- Gas supply pressure or connection
- Several recent gas resets stored in the oven
Other likely causes — what usually sits behind error code Service 140.4 on this control. A technician confirms which one it is before any part is replaced.
- Carbon or moisture bridging the electrode to ground
- Gas pressure dipping when other kitchen appliances start
- Repeated manual resets that stack up the count
Safe checks before calling for service
- Close the gas valve to the oven when the message keeps coming back.
- A gas smell means leaving the building first and phoning the utility from outside.
- Resist pressing reset again and again.
- Call us with the exact message and when it first showed. Leave the panels and the burner area untouched.
How a technician diagnoses error code Service 140.4
- Read the message and the gas reset history in the oven.
- Check gas supply pressure and connections.
- Inspect the ignition electrode and measure its insulation to ground.
- Test the gas valve and the automatic ignition controller.
- Clear the cause behind the resets, not just the count.
- Run several ignition cycles with a gas leak check to confirm.
- Ignition electrodes and gas valves sit in a gas-fired area with high voltage.
- Measuring electrode insulation and valve operation needs test instruments and care.
- Clearing resets without the cause only speeds the lockout.
How error code Service 140.4 differs from similar codes
Service 140.4 is warning level 1 and 2. Service 140.8 is warning level 3, where a repeat inside three days blocks cooking.
Technical reference
- Document
- Technical Information TI_2220 New gas service messages 140
- Edition
- TI_2220_en-GB V02.1, 05/2023 (sheet dated 21/09/2022, series 2022/20)
- Models / control
- SelfCookingCenter (Index H/I, SCC-07-00-10.6.34+), iCombi Pro (Index J, LM100-16.3.28+), iCombi Classic (Index J, LM200-8.0.0+)
- Section
- Trigger criteria and warning levels, printed pp. 1-2 of 4 (Service 140.4 / 140.8); ignition controller error list 17, 18, 22, 37, 38, 42 on p. 3-4 near the end of the sheet
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related Rational combi oven error codes
Does 140.4 mean cooking is blocked?
Not yet. If the problem stays, the oven blocks cooking.
Should I press reset?
Resist pressing it repeatedly, since resets feed the warning count.
Is this a gas leak?
Not necessarily, but if you smell gas leave the building and call the utility.
Need help with Rational error code Service 140.4?
A technician confirms the cause on site and gives you the price in writing before any work starts.