Summary
- The heating system can malfunction if parts like the heater valve fails.
- A heater valve is the device that controls the flow of the coolant from the engine to the heater core. ...
- Usually designed to last up to 100,000 miles, a heater valve can be controlled electronically or by a cable or vacuum.
What are the symptoms of a bad heater control valve?
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- Heater doesn’t work One of the first symptoms of a faulty heater control valve is a heater that fails to produce warm air. ...
- Leaking coolant Another common symptom of an issue with the heater control valve is coolant leaks. ...
- Erratic heater behavior
How to remove and replace a heater control valve?
Part 1 of 1: Replacing the heater control valve
- Distilled or demineralized water
- Drain pan
- New heater control valve
- New engine coolant
- Pliers
- Ratchet set
- Screwdrivers
- Spill-free funnel
How can you get to the heater control valve?
Signs of a Bad Heater Control Valve
- Not all cars have a heater control valve. Some vehicles use a blend door, which is a motorized partition between the heater and the fresh air/AC systems.
- Symptoms of a bad heater control valve. ...
- Repairing a bad heater control valve. ...
- Repairing a bad valve can be tricky. ...
How do I replace the heater control valve?
- Control Valves
- Blend Door Actuators
- Air Inlet Door Actuators
- Mode Door Actuators
- Recirculation Door Actuators
How do I know if my heater control valve is working?
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.More items...•
Can heater control valve cause no heat?
Some vehicles use a heater control valve that only opens (allowing hot coolant to flow through the heater core) when the heater control calls for hot air. The heater will fail to produce warm air if the control valve is stuck closed, leaking or disconnected from the heater control.
What happens if you bypass heater control valve?
Your heater control valve works to deliver heat from the engine to the passenger cabin of your car, and if it has been bypassed, then the cabin will not receive heat. Instead, it will be dissipated by means of the bypass hose.
Do you need heater control valve?
Not all cars have a heater control valve The motion of the blend door balances the amount of hot and cool air coming through the interior vents, based on the climate control system settings chosen. In a blend door system, the heater is always on, so a heater control valve is not necessary to regulate its output.
Why is my car blowing cold air when the heat is on?
Low Coolant Level The coolant (usually a mixture of water and antifreeze) in your engine doesn't just work to keep the engine from overheating: It's also the source of heat supporting the heating system. If there isn't enough coolant in your system, the heater core will blow cold air into your car.
Why is my heat blowing cold air?
A clogged filter is one of the leading reasons for a heater blowing cold air. But even if you swap the air filter with a brand new one, dirt and debris can still be found within the unit. This could eventually lead to overheating. If your furnace looks pretty dirty, call an HVAC provider for a professional clean.
Does heater control valve affect AC?
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.
Can heater control valve cause overheating?
Leaking coolant A coolant leak at the heater control valve is not only a problem in that it will disable the heater, but it will also compromise the cooling system which can cause the engine to overheat.
How much does a heater control valve cost?
They'll likely inspect the other heater hoses during this service. Depending on the car you drive and the auto repair shop you go to it can cost between $181 and $250 to replace your heater control valve.
How long do heater control valves last?
How often do heater control valves need to be replaced? The original heater control valve for most vehicles should last for about 100,000 miles. Low-quality replacement heater control valves will more than likely fail much more quickly. It's worth noting that not all vehicles are equipped with a heater control valve.
Does coolant flow through heater core when heater is off?
When you turn on the heat inside your car, air blows over the heater core, is warmed and comes into the cabin. Some vehicles have a heater valve that directs coolant through the heater core when the heat is on and bypasses the heater core when the heat is off.
What happens when a heater control valve fails?
When the heater control valve fails it can cause issues with the vehicle’s cooling system, and with the operation of the heater. Usually a bad or failing heater control valve will produce a few symptoms that can alert the driver of a potential issue. 1. Heater doesn’t work.
Why does my heater control valve leak?
Leaking coolant. Another common symptom of an issue with the heater control valve is coolant leaks. 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.
How to tell if a 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. by Eduardo Ruelas on January 08, 2016. 1. Heater doesn’t work. 2. Leaking coolant. 3. Erratic heater behavior. Next Step.
Why does my heater control valve stop closing?
However, even if the heater control supplies vacuum the mechanical portion of the valve can fail, preventing the heater control valve from closing. Or, rust or sludge in the cooling system can block the valve and prevent it from closing fully.
What to do if your heater isn't hot enough?
If you have No heat or the heater isn’t hot enough. 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. Check the heater hose on both sides of the heater control valve.
Why does my vacuum stop working?
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. Depending on the amount of vacuum, the vacuum motor will close off the flow of engine coolant fully or partially.
Why does my car not heat up?
No heat due to bad heater control valve. 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 ...
What to do if the inlet side is warmer than the outlet side?
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. If there’s no vacuum, conduct the steps shown below. Next, try moving the mechanical linkage by hand to open the valve. If the temperature still doesn’t change on the outlet side, ...
Can a heater control valve fail?
Vacuum operated heater control valve. 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.
Why is the heater control valve important?
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. Any car engine is built to be as efficient as it possibly can be. When it comes to keeping you warm on ...
Where is the heater control valve located?
In some cars it will be located in the engine compartment but in others you might find it near the passenger side firewall. Some vehicles will also feature the heater control valve behind the dashboard near your passenger’s feet.
What happens if the control valve is stuck in the open position?
If the valve is stuck in the open position, then coolant from the engine will always be rushing through the heater core of your vehicle.
How does coolant work in a car?
When it comes to keeping you warm on a cold day, your car uses heat generated by the engine that has been absorbed by the coolant to provide warmth for you in the cabin. This heated coolant passes through the heater control valve into the heater core in your car's heating system where air will then blow it into the cabin of your vehicle.
What happens if the heater control valve is closed?
If the heater control valve is closed, then that coolants will not enter your heater core and your heater won't be producing heat for you in the cabin. If something goes wrong with your heater control valve then it may not be able to open and close properly, or there can be other issues that prevent your heater from working the way you expect it to.
How much does a heater control valve cost?
On the website autozone.com you can find a range of heater control valves which cost anywhere from $10 to about $50.
Why is there no heat in my heater?
No Heat: Obviously a total lack of heat coming from your heater is a good sign that you're having a problem with your heater control valve. If the heater control valve has failed in a way that prevents it from opening to allow warm coolant to travel from your engine to your heater then when you turn your heater on the fan inside might be able ...
How does a heater valve work?
Once opened, the water flows from the engine coolant jacket in the block and then through the heater core by means of water pressure. Heater valves are also useful to aid with engine heating in the winter. By isolating the heater circuit from the coolant flow, this allows the engine to reach operating temperature faster.
What is heater valve?
Your heater valve is also useful for adding additional cooling to an overheating engine. By opening the heater control valve, you can allow additional coolant to flow through your heater core. The core acts as an additional mini-radiator to keep the coolant system from overheating for a longer period.
What valves do radiators use?
Consider hot water radiators. Technically, each radiator in your house uses a heater control valve in the simplest form. Early automotive valves functioned in the same way a radiator shut-off did.
Can you turn on a heater without starting?
This usually means you cannot turn on the heat without starting the vehicle . The newest designs of heater valves are electronically controlled. These valves depend on electrical voltage to energize a solenoid, which in turn attaches to the piston inside the valve.
How Does The Water Heater Control Gas Valve Work?
I mentioned before that the gas valve controls the gas flow into your gas water heater. But that is not its only job. The smart design of these devices allows them to serve a much more complex function than that.
Troubleshoot The Gas Control Valve
There are many parts involved with the operation of the gas control valve.
Troubleshoot The Heat Limiter And Thermostat
You can choose to replace only the heat limiter or thermostat if they are the parts causing problems. But, it might be a better idea to replace the gas control valve. Doing so is only slightly more expensive.
What Does A Gas Control Valve Cost?
I said before that a gas control valve is a pricey piece of equipment. How expensive it is will vary based on the manufacturer. But you can expect to pay upwards of $100 for a new one. That price doesn’t include the cost of labor if you hire a professional.
It Is Time To Replace Your Faulty Gas Control Valve
Working with natural gas can be quite dangerous. So always turn it off before attempting to repair your gas-powered water heater. Contact a qualified contractor if you are not comfortable working in this atmosphere.
Final Thoughts On Water Heater Gas Control Valve Replacement
Putting a new gas control valve on your water heater is a simple four-step process. Although the gas control valve is expensive, you can save on the cost of labor by doing it yourself.
