Abnormal Recycle: Hardware flame rod short
The 327 error code on Slant-Fin boilers indicates abnormal recycle: hardware flame rod short.
Slant-Fin 327 means: abnormal recycle: hardware flame rod short. On this component the documented failure modes are no gas reaching the burner, or the gas supply is shut off, ignition or detection electrode dirty, worn or out of position or flue or air intake blocked or restricted. You can safely reset the boiler once — if 327 returns, do not keep resetting. A qualified heating engineer should diagnose the root cause.
What Does 327 Mean
The 327 code is shown by the boiler’s control board when it detects abnormal recycle: hardware flame rod short. 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 327 and the boiler stops until the fault is cleared |
Common Causes
The manufacturer does not publish a cause list for this specific code. The causes below are the failure modes documented for the same component on other boilers, confirmed by the service literature of 11 different manufacturers.
| Cause |
|---|
| No gas reaching the burner, or the gas supply is shut off |
| Ignition or detection electrode dirty, worn or out of position |
| Flue or air intake blocked or restricted |
| Mains gas pressure too low |
| Faulty gas valve, or its wiring and connector |
Safety Warning
327 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
Check that the gas service valve is open and that other gas appliances in the property work. If they do not, the problem is the gas supply, not the boiler.
Inspect the ignition and detection electrode: clean off any deposits, check the gap and position against the manual, and replace it if it is worn.
Inspect the flue and air intake along their whole length, including the outside terminal, and clear any obstruction or debris.
Have the inlet gas pressure measured at the boiler with a manometer and compared against the figure in the manufacturer’s data table.
Check the gas valve connector and wiring for continuity, then test the valve coil resistance against the manual; replace the valve if it is out of range.
Refer to the Slant-Fin service documentation for the detailed procedure. Only a qualified engineer should carry out these repairs.
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Affected Models
Slant-Fin models that can display fault code 327:
| Model Family | Output Range | Frequency |
|---|---|---|
| All Slant-Fin models | — | Possible |
Frequently Asked Questions
Check that the gas service valve is open and that other gas appliances in the property work. If they do not, the problem is the gas supply, not the boiler. According to the technical documentation, this is the first check on the list for 327.
327 is not classified as a high-severity fault, so the boiler can be reset once. If 327 comes back, stop resetting: the underlying cause is still there and needs a qualified heating engineer.