On 09 July 2011, I requested Air Conditioning service for my home AC unit from B & B Air Conditioning and Heating Co. Inc in Sterling Va. and was told the cost for B & B to come out and diagnose the problem would be $110.00 for the first half hour and $45.00 for each additional quarter hour. And this would not include any repair work. That cost would be separate and additional. I agreed and a service man arrived within the hour. It was low on refrigerant and the serviceman informed me to further diagnose the cause, he would need to use a tool called a Leak Detector for an additional cost of $90.00. I needed to know the cause, so I said proceed. In a follow-up visit with a B & B management team, asking why was I charged $90.00 for the use of a diagnostic Leak Detector tool and why was that not part of the cost to diagnose the problem ? B & B management replied, the additional cost for the use of the Leak Detector was for the serviceman’s labor (5 minutes) and not the use of the tool. In all, I'm paying for his time to be there and the additional cost of his time to use this tool. Total cost $620.00 for adding refrigerant. I would not recommend B & B.