What happens when a heater control valve is stuck?
If the heater control valve is stuck closed depriving the heater core of heated coolant, the inlet hose to the heater core will be hot and the outlet hose much cooler. This can be caused by a clogged heater core. A leaking heater core will leak onto the floorboard and result in a sweet humid smell (coolant) coming from the vents while in operation.
How does a heater control valve work in a car?
It uses heated engine coolant to provide heat to the passenger compartment. A heater control valve controls the amount of coolant flowing through the heater core. It’s not used in all heater systems, as some manufacturers allow coolant to flow through the heater core any time the engine’s running.
How does a vacuum valve work in a heater?
The vacuum valve does the same thing with a pintle and diaphragm, except this type of valve is normally open. This is in case of malfunction; heat may still be provided to the occupants by the heating system. The engine supplies vacuum through a switch in the dash.
Where is the coolant valve on an AC heater?
It may be located on the inlet or the outlet port of the heater core and activated by a cable, electronic control, or a vacuum signal. This valve may be normally open, allowing coolant to flow until activated, or normally closed, allowing coolant to flow only when activated.
How does a cable operated heater control valve work?
A cable-operated heater control valve uses a Bowden cable to drive a flap located inside the valve. As the occupant manually moves a lever in the control panel, the cable moves a flap in the valve. The vacuum valve does the same thing with a pintle and diaphragm, except this type of valve is normally open.
If the heater control valve is stuck closed depriving the heater core of heated coolant, the inlet hose to the heater core will be hot and the outlet hose much cooler. This can be caused by a clogged heater core. A leaking heater core will leak onto the floorboard and result in a sweet humid smell (coolant) coming from the vents while in operation.
It may be located on the inlet or the outlet port of the heater core and activated by a cable, electronic control, or a vacuum signal. This valve may be normally open, allowing coolant to flow until activated, or normally closed, allowing coolant to flow only when activated.