What happens when the heater control valve goes bad?

Heater doesn’t work If the heater control valve breaks or gets stuck, the coolant flow to the heater core may be restricted or stopped completely. Without coolant flow to the heater core, the heater will not be able to produce warm air for the cabin.

What are the signs of a bad heater control valve?

Many factors can cause a bad heater control valve. Here are some of the warning signs of a bad heater control valve: Heater operates erratically, putting out more or less heat without any control changes Higher-than-normal temperature gauge readings (from loss of coolant)

What happens when a heater core goes bad?

A heater core often goes bad due to leaking. As the heater core uses engine coolant to generate heat, a leaking heater core will reduce the amount of coolant in the cooling system. Low coolant will cause an engine to run at a higher temperature, which can result in extensive engine damage. Can a Bad Heater Core Cause Overheating?

What happens if a heater control valve breaks?

One of the first symptoms of a faulty heater control valve is a heater that fails to produce warm air. If the heater control valve breaks or gets stuck, the coolant flow to the heater core may be restricted or stopped completely. Without coolant flow to the heater core, the heater will not be able to produce warm air for the cabin.

Can a bad blower motor indicate a bad heater core?

It may indicate that your blower motor or another component of your heater has gone bad (cheer up, it may be a component that’s less tedious to fix than the heater core). Though, if you’re seeing one of the other signs in addition to a lack of heat that’s a pretty good indicator that the heater core itself has a problem.

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.

What causes coolant to leak out of a heater?

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 can you tell if a heater control valve is working?

A quick test to see if it’s working is to feel the hose before and after the valve. If it’s the same temperature after the valve, it’s open and working fine. You must have the heat on when doing this test. If the outlet is cool or cold and the inlet is hot, look to the valve for the issue. It might not be the valve’s fault though.

Why do I need a heater control valve in my car?

You wouldn’t want your cold AC air to pass through a hot heater core before it enters the passenger compartment, so this heater control valve regulates coolant flow into the heater core. If this valve has an issue, it can cause no heat or AC that doesn’t cool enough.