Ask technician to D-rate a gas wall heater for high altidude. The first comment that he made after I stated that the tenant smelled gas was that it could be a cracked vent pipe. At this point, he hadn't even tested the heater. Technician stated that D-rating wouldn't solve the issue present. Since I already had TLC do several other heaters with the same issue, I asked him to do it anyway and retest the heater. He replied that he could do it and would take some time. I watched him getting started comparing to what I wittnessed with TLC and it made me wonder about his qualifications. I decided to ask him to leave. TLC came in yesterday and D-rated the heater and it is working properly. When I made the appointment, I explained what needed to be done; all the technician was told that there was a gas leak. Would he have been told what I requested, he might have asked to send someone else. I paid the trip charges of $85.22. I would have given 0 stars if that were an option.