Tripping of the safety thermostat and/or siphon pressure switch
The 07 error code on Sime boilers indicates tripping of the safety thermostat and/or siphon pressure switch.
Sime 07 means: tripping of the safety thermostat and/or siphon pressure switch. The usual cause is the boiler stops due to the intervention of the safety thermostat or the intervention of the siphon pressure switch. the system pump remains in operation for one minute. You can safely reset the boiler once — if 07 returns, do not keep resetting. A qualified heating engineer should diagnose the root cause.
What Does 07 Mean
The 07 code is shown by the boiler’s control board when it detects tripping of the safety thermostat and/or siphon pressure switch. The boiler then stops instead of continuing to run in that condition: the code is the appliance reporting a problem, not proof that the boiler is broken.
| What you see on the boiler |
|---|
| The display shows 07 and the boiler stops until the fault is cleared |
Common Causes
Causes documented in the Sime service literature published by centriassistenza.org, cross-checked against the manufacturer’s fault-code table.
| Cause |
|---|
| The boiler stops due to the intervention of the safety thermostat or the intervention of the siphon pressure switch. The system pump remains in operation for one minute |
Safety Warning
07 involves electrical or pressure-related components. Do not attempt repairs without proper qualifications. Ensure the boiler is electrically isolated before any inspection. If you notice water leaks, unusual sounds, or pressure anomalies, contact a qualified heating engineer immediately.
Parts & Prices
Prices shown are indicative. Actual prices and availability vary by region.
Step-by-Step Diagnosis
Consult service manual
Refer to the Sime service documentation for the specific diagnosis procedure for fault code 07.
Check error log
Access the boiler error log to check for related fault codes that may help identify the root cause.
Contact manufacturer support
If the fault persists after basic checks, contact Sime technical support for specialist guidance.
How to Fix It
Remove and flush the condensate trap, and clear the condensate pipe. If the pipe runs outside, check it is not frozen.
Refer to the Sime service documentation for the detailed procedure. Only a qualified engineer should carry out these repairs.
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Affected Models
Sime models that can display fault code 07:
| Model Family | Output Range | Frequency |
|---|---|---|
| All Sime models | — | Possible |
Frequently Asked Questions
07 is not classified as a high-severity fault, so the boiler can be reset once. If 07 comes back, stop resetting: the underlying cause is still there and needs a qualified heating engineer.