Technician diagnosing a fault at an HVAC control panel

Fault site survey and diagnosis

We do not replace parts by guesswork. We measure first, find the cause of the fault, and present repair options in writing.

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In shortA fault survey finds the real cause of a breakdown by reading the unit's error code, measuring pressure, superheat, current and temperature, and testing the electrical and control circuits. At the end of the survey, YOİ Mühendislik reports the fault, the recommended repair and the cost in writing; if the repair is approved, the survey fee is deducted from the total price.
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About fault site survey and diagnosis

The same symptom can have different causes: an AC that is not cooling may have a refrigerant leak, a dirty condenser, or a faulty sensor or PCB. A wrong diagnosis leads to unnecessary part replacement and recurring breakdowns. That is why the site survey involves measurements, records and a clear decision.

Scope of service

  • Reading error codes and alarm history
  • Pressure, superheat and subcooling measurement
  • Compressor and fan current measurement
  • Winding insulation (megger) test
  • Sensor, control board and communication line test
  • Preliminary refrigerant leak scan
  • Diagnostic report with photos and measurements
  • Written quote for repair and replacement options
YOİ Mühendislik technician taking measurements with a manifold on a VRF outdoor unit
Diagnosis is made by evaluating pressure, current, temperature and fault codes together.

Our site survey process

  1. Collecting the symptom, error code and unit label information
  2. On-site measurements and tests
  3. Identifying and recording the cause of the fault
  4. Repair options and written cost estimate
  5. Repair with your approval; the survey fee is deducted if we carry out the repair

Buildings we serve

Home and officeStore and restaurantHotel and hospitalData centerFactoryPublic building

Our base is in Ankara Etimesgut. We provide fault diagnosis and site survey services daily in Ankara, and on a project and contract basis in all 81 provinces of Türkiye, including İstanbul, İzmir, Bursa, Antalya, Konya, Kayseri, Eskişehir, Kocaeli, Adana, Gaziantep, Samsun and Trabzon. See our service areas.

Frequently asked questions

Is there a charge for the fault site survey?

A site survey fee is charged for fault diagnosis; if you approve the repair, this fee is deducted from the total repair cost.

What should I prepare before the site survey?

Sending a photo of the unit's make/model label and the error code on the display via WhatsApp helps the team arrive with the right equipment.

Do I get a written report after the site survey?

Yes. The identified fault, measured values and recommended repair options are provided in writing.

Can the fault be fixed during the site survey?

Simple faults (fuse, filter, sensor connection, etc.) are often fixed during the site survey; for jobs that require parts, an appointment is scheduled with your approval.

Serviced together

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From 1 unit to 1,000 units, from a single provider.

Sales, installation, maintenance and repair for all brands and equipment. Nationwide across Türkiye.

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