Heater not working properly

RBLEO

MEMBER
2008 CHEVROLET HHR
90,000 MILES

Defroster is working fine/ heater puts out no warm/hot air when heater is turned on. Have tried to set on low setting with warm heat requested, then high fan setting with hot air requested, but nothing happens. Is a fuse or sensor out or is there a control valve setting or cable loose below the dash that opens a flap to allow this air to be forwarded by the heater? Need some help as this is getting to be a real issue. Thanks --Randy B

1 Reply

ASEMASTER6371

MECHANIC
52,797 POSTS

Okay, I attached the procedure for replacing the thermostat.

https://www.2carpros.com/articles/replace-thermostat

I also attached a wiring diagram of the blower system. There is no fuse but we need to do some voltage checks to find the failure. Check for power to the blower motor and the blower resistor in the wire I highlighted.

https://www.2carpros.com/articles/how-to-check-wiring

Roy

Engine Coolant Thermostat Replacement (LE5-2.4L, L61-2.2L, LE5)

Removal Procedure

imageOpen In New TabZoom/Print

1. Drain the cooling system. Refer to Cooling System Draining and Filling (Static Fill-LE5, L61) (See: Cooling System > Removal and Replacement)Cooling System Draining and Filling (GE 47716 Fill) (See: Cooling System > Removal and Replacement).
2. Reposition the radiator outlet hose clamp at the thermostat housing.
3. Remove the radiator outlet hose from the thermostat housing.

imageOpen In New TabZoom/Print

4. Remove the thermostat housing cover bolts and cover.
5. Remove the thermostat.
6. Remove and discard the thermostat housing O-ring seal.

Images (Click to make bigger)