While Csaba is definitely right about the translation of the part "klima és légtechnikai", obviously the last word in your term "szerelés" is not "repairman" in Hungarian (but you already knew that :)), as Katalin pointed out.
On this particular certificate, the name of the qualification is "HŰTŐ ÉS KLÍMABERENDEZÉS SZERELŐ, KARBANTARTÓ" - that is, Heating, Ventilation & Air Conditioning (HVAC) Technician. In order to successfully pass the exam and obtain such qualification, students are required to complete certain tasks, "KLÍMA ÉS LÉGTECHNIKAI SZERELÉSI FELADATOK" - that is, "Heating, Ventilation & Air Conditioning (HVAC) Service Tasks."
Such service work may include installation (beszerelés), servicing & repair (szerelés & javítás) and maintenance (karbantartás).

Please see detailed (US) training description below:

Heating, Ventilation & Air Conditioning
We balance hands-on training, classroom instruction and computer simulations to give you a well-rounded education. This method of teaching will not only give you the skills you need, but also train you to utilize those skills correctly in the most challenging situations. A tool kit is included in the cost of this program!
Gain the technical skills to service, maintain and troubleshoot heating, air conditioning and refrigeration units. Become a certified HVAC technician at Institute of Technology and prepare for a variety of commercial and residential areas, such as:
Sales
Contracting
Servicing
Installation
Repair and maintenance

(Institute of Technology, California)
http://www.it-colleges.edu/iot/t-heating-ventilation-and-air...

Example for an "HVAC Service Technician" job:
"ModSpace is seeking an experienced HVAC Technician to perform service calls at customer sites."
http://www.jobhost.org/jobs/viewjob/hvac-service-technician-...