HouseWarmer Slim-Profile Direct-Vent Wall Heater with Built-In Blower - 18,000 BTU, Propane, Model# HWDV181BDVP Mounts on any outside/exterior wall from 4 1/2in.-12in. thick Thermocouple safety valve Heater requires no electricity (electricity required for blower) Easy to install 10-year limited warranty on heat exchanger; 1 year on balance of product