Yes it could be the thermostat. Check or replace thermostat first. Let me know how it goes?
BASIC HEATER SYSTEM TROUBLE SHOOTING CHART
CONDITIONPOSSIBLE CAUSE
Insufficient, Erratic, or No Heat
. Low Coolant Level
. Incorrect thermostat.
. Restricted coolant flow through core.
. Heater hoses plugged.
SPONSORED LINKS
Wednesday, December 10th, 2008 AT 11:29 AM