External overheating protection is activated or the T_Supply sensor measures a temperature
The verrouillage error code on Utica boilers indicates external overheating protection is activated or the t_supply sensor measures a temperature.
Utica verrouillage means: external overheating protection is activated or the t_supply sensor measures a temperature. The usual causes are the heat exchanger thermal fuse has tripped, fil desserré or bcu ou pb mal programmés. You can safely reset the boiler once — if verrouillage returns, do not keep resetting. A qualified heating engineer should diagnose the root cause.
What Does verrouillage Mean
de sur Prot_Overheat_Temp — SGOverheat_Duplex_Tolerance pour une période de Max_Value_Period
The verrouillage code is shown by the boiler’s control board when it detects external overheating protection is activated or the t_supply sensor measures a temperature. 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 verrouillage and the boiler stops until the fault is cleared |
Common Causes
Causes documented in the Utica service literature published by uticaboilers.com, cross-checked against the manufacturer’s fault-code table.
| Cause |
|---|
| The heat exchanger thermal fuse has tripped |
| fil desserré |
| BCU ou PB mal programmés |
| incorrect grounding of BCU and boiler |
| If the outlet is programmed as a fill valve and there are too many fill attempts |
| If the outlet is programmed as a fill valve and filling takes more than 10 minutes |
Safety Warning
verrouillage 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.
How to Fix It
If the boiler does not start after resetting, contact the installer
Check if there is a leak in the central heating system or if the boiler itself is leaking also check the expansion tank if there is an internal leak
Refer to the Utica service documentation for the detailed procedure. Only a qualified engineer should carry out these repairs.
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Affected Models
Utica models that can display fault code verrouillage:
| Model Family | Output Range | Frequency |
|---|---|---|
| All Utica models | — | Possible |
Frequently Asked Questions
If the boiler does not start after resetting, contact the installer. According to the technical documentation, this is the first check on the list for verrouillage.
verrouillage is not classified as a high-severity fault, so the boiler can be reset once. If verrouillage comes back, stop resetting: the underlying cause is still there and needs a qualified heating engineer.