ACV · Kompakt HR eco combi condensing boiler · Europe

27 error code

ACV Kompakt HR eco 27 error code – External temperature sensor short circuit

FaultUnknownAlso: Kompakt HR eco; Kombi Kompakt HR eco; HR eco combi3 min read
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Quick answer

What does ACV Kompakt HR eco combi condensing boiler 27 mean?

ACV documents display code 27 for the Kompakt HR eco 24/28 and 30/36 combi boilers as: External temperature sensor short circuit.

The code identifies the condition detected by the product; it does not always identify the failed component on its own. Confirm the full code and exact model before ordering parts or attempting a reset.

The ACV Kompakt HR eco combi condensing boiler 27 error code indicates aCV documents display code 27 for the Kompakt HR eco 24/28 and 30/36 combi boilers as: External temperature sensor short circuit. This guide explains what the code means, the symptoms and likely causes, the checks that are safe to make, and when to stop and arrange an authorised repair.

Symptoms you may notice

The fault indicator flashes and the temperature display shows 27. The boiler may lock out, stop firing, or interrupt central-heating or domestic-hot-water operation.

Common causes

The official table identifies a short circuit in the outdoor-temperature sensor circuit; the sensor wiring or the sensor may be defective.

Before you start troubleshooting

Use the display, rating label or product menu to confirm the exact model. Similar-looking codes can have different meanings across product generations and regions.

  • Record the complete code before switching the equipment off.
  • Check only user-accessible controls, filters and external connections described in the manual.
  • Do not open gas, refrigerant, combustion or electrical compartments.

Troubleshooting steps

Record code 27 and the exact Kompakt HR eco model. Check only the visible pressure, electrical supply, thermostat demand and external controls permitted by the operating instructions. Internal sensor, fan, ignition, gas-valve, relay and combustion tests require a qualified engineer.

Can you fix this error code yourself?

The safest next step depends on the exact model and the cause behind the code. External checks may help, but a returning fault needs professional diagnosis.

A successful reset is not proof that the underlying issue is fixed. If 27 reappears, note when it happens and give that information to the service engineer.

Reset instructions

After the underlying fault has been corrected, hold the reset button for five seconds as specified in section 8.1 of the official manual. If code 27 returns, stop resetting and arrange professional diagnosis.

Applicable products and models

ACV Kompakt HR eco combi condensing boiler Kompakt HR eco 24/28; Kompakt HR eco 30/36Kompakt HR eco combi condensing boilerKompakt HR eco 24/28; Kompakt HR eco 30/36Official installation manual, © 2022 ACV International

When to contact a professional

Contact ACV support or a qualified heating engineer when code 27 persists, returns after a permitted reset, or requires internal testing, adjustment or component replacement.

Frequently asked questions

What does ACV Kompakt HR eco combi condensing boiler 27 mean?

ACV documents display code 27 for the Kompakt HR eco 24/28 and 30/36 combi boilers as: External temperature sensor short circuit.

Can I fix ACV Kompakt HR eco combi condensing boiler 27 myself?

Some external checks may be suitable for the user, but the result depends on the exact model and cause. Use the official manual and arrange service if the code returns.

Should I reset the product after code 27?

After the underlying fault has been corrected, hold the reset button for five seconds as specified in section 8.1 of the official manual. If code 27 returns, stop resetting and arrange professional diagnosis.

When should I arrange a repair?

Contact ACV support or a qualified heating engineer when code 27 persists, returns after a permitted reset, or requires internal testing, adjustment or component replacement.