Dave from Schaefer Mechanical came out and diagnosed my AO Smith water heater problem in a timely manner and explained the possible solutions. After changing the gas control valve and igniter assembly, the water heater is working as it should. Everyone at the company is professional and pleasant to deal with. Something you can’t say about most service oriented businesses these days. They even pro-rated the time and did not charge some additional time used for getting parts, phone calls, etc. Definitely use them if you are in the Baltimore/Carroll County area. Good, honest, professional people. Reasonable fees.