NSG is led by a technician with over 30 years of experience in the HVAC sector, specialising in the diagnosis, maintenance and repair of air conditioning systems. He has worked as an official technical service provider for a leading Japanese brand, providing a solid foundation and in-depth knowledge of the most advanced equipment on the market. 

Because we combine professional technical expertise with a friendly, personalised service. Each customer receives attention tailored to their needs, ensuring accurate diagnoses and lasting solutions.

We work with all types of HVAC equipment: split systems, multisplit systems, VRF systems, aerothermal systems, CO₂ heat pumps, and industrial equipment. Our experience ranges from residential installations to large commercial projects.

Yes. At NSG, we specialise in high-precision technical diagnostics, using our own instruments and equipment developed by us, such as the EEV CHECKER, to detect faults that other methods cannot identify.

Of course. We design customised maintenance plans, tailored to each type of installation, to prevent breakdowns, reduce energy consumption and extend the useful life of the equipment.

Yes. We offer services to private customers as well as businesses, installers and maintenance providers, ensuring the same level of technical quality and personalised attention in all cases.

What sets us apart is our technical precision and professional integrity. Every diagnosis is based on real data and proven experience, not assumptions. We always seek the most efficient and cost-effective solution for the customer.

Each job is carried out under rigorous technical protocols, personally verified by a professional with extensive experience. In addition, we use advanced tools and verification methods that ensure reliable results.

Yes. NSG also provides advice and technical support to installers and companies, particularly in resolving complex faults and commissioning VRF systems or heat pumps.

You can contact us directly through our official website, by email or WhatsApp. We respond to each enquiry individually and provide guidance based on your specific needs.

The EEV CHECKER is a portable device designed to test and diagnose four-phase single-pole electronic expansion valves (EEVs) used in air conditioning equipment and VRF systems. It allows you to verify their operation without the need for the original controller.

The EEV CHECKER works with most unipolar stepper motor valves on the market. It is currently compatible with four-phase unipolar valves (4 wires + common). These are found in most VRF, split and direct expansion equipment on the market.

Yes. 

However, it is always advisable to disconnect the valve from the equipment before connecting the EEV CHECKER, to avoid interference or damage to the original controller.

Enables quick, safe and portable diagnostics without the need to dismantle the valve or use external controllers. Saves time and reduces errors in repair or maintenance. 

No.

It is an intuitive tool designed to facilitate diagnosis for both junior and senior technicians.

Yes. 

Each unit comes with a QR code from which you can download the manual in different languages, explaining step by step how to connect, calibrate and operate the device.

Yes.

As long as the valve is a 4-phase unipolar valve, the EEV CHECKER is compatible with brands such as Mitsubishi, Daikin, LG, Panasonic, Toshiba, among others. 

The equipment has built-in electronic protection that prevents damage from incorrect connections or reversed polarity. 

You can purchase it directly through our official website or by contacting us. We ship to any country in the EU, UK, and Latin America. 

Of course. The EEV CHECKER comes with a one-year warranty against manufacturing defects and direct technical support to resolve any queries or incidents.