Where is heater control valve located?
The heater control valve allows the flow of coolant through the heater core to be controlled and switched on and off without affecting the operation of the rest of the cooling system. 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.
What happens when a heater control valve is bad?
The heater may produce hot air, but only at certain times, such as at idle, and the hot air may come and go. A faulty heater control valve may also cause the temperature gauge to behave erratically, rapidly climbing and falling, which will make it difficult to determine the temperature of the engine.
How does a vacuum heater control valve work?
The heater control valve either permits or restricts coolant flow through the heater core, depending on whether vacuum is applied to it. It is a normally OPEN valve which closes when vacuum is applied. When the valve is open, coolant circulates through the heater core and you have heat.
How do you test a heater control valve?
How Do You Test a Heater Control Valve?
- Bring the engine up to operating temperature and switch the heater to the hottest setting.
- Check the temperature of the valve’s outlet hose (between the valve and the heater core)—it should feel nearly as hot as the valve’s inlet hose.
What is the function of heater control valve?
The heater control valve (sometimes called the hot water valve) is used to control the rate at which coolant flows through the heater core. The valve is located on the heater inlet hose.
Does heater need control valve?
That’s why it is surprising for some people to learn that the heater control valve is a necessary part of how the heater works because it allows coolant to pass from the engine itself through the car heater where it’s able to warm you up.
How to check the temperature of a heater control valve?
Then check the temperature of the hose on the inlet and outlet sides of the heater control valve. The inlet and outlet hoses should be the same temperature. If the inlet side is warmer than the outlet side, the valve isn’t opening or opening fully. Remove the vacuum line from the vacuum motor and check for engine vacuum.
Where are the heater control valves located in a car?
Some heater control valves will be located in the engine compartment at or near the passenger side firewall. Others are located behind the dashboard near the passenger footwell.
What can cause a heater control valve to fail?
A heater control valve can fail in several ways. Since a vacuum operated valve defaults to the fully open heat-on position when vacuum isn’t applied, a loss of vacuum is the first thing to suspect in a “heat always on” condition. The loss of vacuum can be caused by a break in a vacuum line or a faulty vacuum switch.
How does an air conditioner control valve work?
During times when the air conditioner is in use, the heater control valve closes, preventing engine coolant from entering the heater core. The result is less heat in the passenger compartment, allowing the air conditioner to work more efficiently.
Where is the heater / AC control vacuum check valve and the check valve?
In case this is not making sense no. 5 in the first pic is the source vacuum no.5 in the connector pic. No. 13 in the first pic is to intake manifold vacuum. This helps a lot. To confirm, what I need to do is: 2) Install – anywhere convenient – a new reservoir and check valve (items 15 and 14 in the diagram)
A heater control valve can fail in several ways. Since a vacuum operated valve defaults to the fully open heat-on position when vacuum isn’t applied, a loss of vacuum is the first thing to suspect in a “heat always on” condition. The loss of vacuum can be caused by a break in a vacuum line or a faulty vacuum switch.
Some heater control valves will be located in the engine compartment at or near the passenger side firewall. Others are located behind the dashboard near the passenger footwell.
What causes a vacuum to go out on a heater?
Since a vacuum operated valve defaults to the fully open heat-on position when vacuum isn’t applied, a loss of vacuum is the first thing to suspect in a “heat always on” condition. The loss of vacuum can be caused by a break in a vacuum line or a faulty vacuum switch. To repair a faulty switch, you sometimes have to replace the heater control.
