Preformed Cooling maintenance. Filter clean Checked all electrical components and refrigerant charge. Unable to rinse coils due to water shut on/off not functioning properly. System currently cooling, draining, functioning properly, & at manufacturer specifications at this time. Cooling maintenance form filled out and attached. Homeowner asked if I could repair doorbell and found low voltage for doorbell & transformer not wired properly. I attempted to wire doorbell low voltage up properly and found/heard electrical buzzing within wall near outlet to where transformers possibly tied into. - Recommend homeowner call license electrician to diagnose problem before attempting to connect up to that transformer.