Welcome to our Blog page!

Our blogs are updated once a month, usually on the first day of the month. On this page, we offer advice, tips, and insights for becoming a safer driver and for better travels on Chico roads. Bookmark this page and remember to check back!

If you need auto repair service, don’t forget that you can schedule an appointment at this link for D&E Auto Repair in Chico. We look forward to seeing you! Remember that you are a part of the family at D&E Auto Repair in Chico. We’re located at 3328 Esplanade St., Chico, CA 95973.

The Hot Switch (Coolant Vacuum Valve Switch)

When the weather gets cooler, you want the cabin of your vehicle to stay warm.  When you switch on the heat, you may find the air that comes out of the vents just isn't hot. 

The problem could be a part in the heating system that not that many people understand.  It's called the coolant vacuum valve switch or thermostat vacuum switch.  Here's what it does.

When you don't need heat in your vehicle, you don't need hot coolant from your radiator to go through the heater core in your vehicle.  (The heater core is like a small radiator that exchanges heat between the coolant and your cabin air.)  When you turn on the switch for heat or defrost, it signals the coolant vacuum valve switch to open.  That should send hot coolant to the heater core which heats your cabin air or defroster air.  If the coolant vacuum valve switch isn't working, you don't get warm air to either.

Sometimes the coolant vacuum valve switch can crack, be jammed up with dirt or debris, or even be clogged up with old coolant.  Another sign your coolant vacuum valve switch isn't working is engine overheating. If it’s cracked, you may see coolant leaking under the dash or smell an odd, sweet odor. 

If you notice any of these symptoms, you should have your vehicle checked out at your NAPA AutoCare Center.  Other things can cause your heat to stop working - your qualified technician will be able to diagnose the problem.  Make sure you and your passengers stay warm, and your windshield is properly defrosted.

CHICO, CA 95973
(530) 343-9703


Cooling System