(Circuit B, Compressor 1 Failure) T056
The P055 error code on Carrier boilers indicates (circuit b, compressor 1 failure) t056.
Carrier P055 means: (circuit b, compressor 1 failure) t056. The usual causes are add strike to compressor, automatic or (max 3). You can safely reset the boiler once — if P055 returns, do not keep resetting. A qualified heating engineer should diagnose the root cause.
What Does P055 Mean
The P055 code is shown by the boiler’s control board when it detects (circuit b, compressor 1 failure) t056. 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 P055 and the boiler stops until the fault is cleared |
Common Causes
Causes documented in 1 technical sources.
| Cause |
|---|
| Add strike to compressor |
| Automatic |
| (max 3) |
| High pressure switch, compressor |
| current, wiring error |
| T055 |
Safety Warning
P055 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
Note the exact error code and check the manufacturer's installation and service manual for specific guidance
Check all visible wiring connections for security and condition
Power cycle the boiler — switch off at the mains for 30 seconds, then switch back on
If the fault recurs, check the fault history for related or recurring codes
Inspect the boiler for any obvious signs of damage, leaks, or unusual sounds
How to Fix It
Reset the boiler after investigation
repair any loose connections or damaged wiring
replace the faulty component identified during diagnosis
if the fault persists after basic checks, contact a qualified heating engineer with the exact error code
Refer to the Carrier service documentation for the detailed procedure. Only a qualified engineer should carry out these repairs.
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Affected Models
Carrier models that can display fault code P055:
| Model Family | Output Range | Frequency |
|---|---|---|
| All Carrier models | — | Possible |
Frequently Asked Questions
Reset the boiler after investigation. According to the technical documentation, this is the first check on the list for P055.
P055 is not classified as a high-severity fault, so the boiler can be reset once. If P055 comes back, stop resetting: the underlying cause is still there and needs a qualified heating engineer.