GM Construction Residential Commercial Installer Servicer 18 years in business Address: 15133 Tombstone Creek Rd, EL CAJON California, 92021 Phone: 6195046708 Working days: SU MO TU WE TH FR SA About Company Number of employees: 1 Company history and description: I've been installing and servicing tankless water heaters since 2006. I have attended Noritz factory classes on many occasions.