Dave Henninger has cleaned & serviced our System 2000 heater for several years. He is very efficient and reliable. He is an excellent service technician and we highly recommend him. A few years ago he came to clean our heater and noticed a potential problem and fixed it before it caused a breakdown during the upcoming winter. He does a complete check of your heater every time he cleans it. The best technician Walton has on staff. John B. Kulpsville