A HVAC heater control valve is an essential component of any HVAC system. It is responsible for controlling the flow of hot or cold air into the home, depending on the season. The valve is usually located near the furnace or air handler and is operated by a thermostat. The valve opens and closes depending on the temperature setting of the thermostat. When the temperature setting is higher than the current temperature, the valve opens and allows hot air to flow into the home. When the temperature setting is lower than the current temperature, the valve closes and prevents cold air from entering the home. The valve is an important part of the HVAC system, as it helps to regulate the temperature of the home and ensure the comfort of its occupants.