Get your drains open and flowing again like new. Pour approximately half the bottle (500ml) down the drain of the affected area. What an amazing group of folks it has been a pleasure to see this company evolve they are doing it right!! very community and service oriented always willing accommodate they even responded to help me christmas eve at 9:00 p.m. Hvac license numbers in: h0010016. The thermal actuator twa range is used with electrical on/off-controls.