Can a faulty heater control valve be repaired?
To repair a faulty switch, you sometimes have to replace the heater control. Depending on the amount of vacuum, the vacuum motor will close off the flow of engine coolant fully or partially. However, even if the heater control supplies vacuum the mechanical portion of the valve can fail, preventing the heater control valve from closing.
Where is the control valve on a heater?
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.
Why is my heater control valve leaking coolant?
Over time the heater control valve can wear out and crack, which will cause coolant to leak from the valve. Heater control valves can also leak from excessive corrosion from contact with old or contaminated engine coolant. Usually a leaking control valve will have to be replaced in order to repair the leak.
How can I tell if my car heater is not working?
Common signs include the heater not working, coolant leaking from under the engine, and no voltage across the heater control valve. 1. Heater doesn’t work 2. Leaking coolant 3. Erratic heater behavior Average rating from 129,829 customers who received a Vehicle Engine Cooling Inspection.
What happens if you have a bad heater control valve?
Higher-than-normal temperature gauge readings (from loss of coolant) While a lack of interior heat from a bad heater control valve is a serious enough problem, the real danger from a bad heater control valve is the possibility that enough coolant could leak out to cause your engine to overheat.
How do you replace a gas control valve on a water heater?
Take the original valve with you to the hardware or gas supply store to get a matching replacement. Reconnect the new valve in reverse order. If you do not detect gas or a rotten egg odor, relight the pilot and verify that the water heater is working properly. Newer models may have wires connected to the gas control valve.
How does a heater control valve work in a car?
The heater control valve (or hot water valve) opens to allow hot coolant from the engine to flow through the heater core, which heats the air supplied to the passenger compartment. Adjusting the temperature may not change the output from the heater. Valve may leak coolant.
Over time the heater control valve can wear out and crack, which will cause coolant to leak from the valve. Heater control valves can also leak from excessive corrosion from contact with old or contaminated engine coolant. Usually a leaking control valve will have to be replaced in order to repair the leak.
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.
In some cars, the heat is regulated by a heater control valve that controls the flow of hot engine coolant from the engine to the car’s heater core. On older vehicles, the valve is operated by a cable, while newer vehicles used a vacuum actuator controlled valve. A heater control valve can fail in several ways.
What to do if your heater is not blowing hot air?
Pinch off the hose on the outlet side of the heater control valve (the hose closest to the firewall) and drive the vehicle at highway speeds. If the blower stops blowing hot air, you’ve found the problem.
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.
What to do if your heater control valve breaks?
On a cable operated system, the cable can break or detach from the control levers, leaving the valve in the fully open position. Adjust the heat to the full on position with the engine at operating temperature. Then check the temperature of the hose on the inlet and outlet sides of the heater control valve.
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.
Pinch off the hose on the outlet side of the heater control valve (the hose closest to the firewall) and drive the vehicle at highway speeds. If the blower stops blowing hot air, you’ve found the problem.