It can, if the engine is not warming up.
A definite maybe!
Other causes might be:
See "Related Questions" below for more
Yes.
Thermostat and/or heater core may be defective
Running a vehicle without a thermostat will cause it to take longer to warm up and your interior heater may not blow hot air.
heat core. leak. thermostat. no antifreeze.
Check the thermostat or heater core
the thermostat may be stuck open or the heater core may be plugged the thermostat may be stuck open or the heater core may be plugged
No, not if it's on a heat setting. Most home thermostats have a "Fan" setting that will blow cold air if the attic is cold.
It could be the thermostat on the engine. If the engine does not warm up adequately the heater will never blow hot air.
Most likely cause is a failed engine thermostat.
thermostat is stuck With my car, it was Heater matrix clogged with radiator sealant. The workshop cleaned it and it's start working fine!
Could be, low on coolant, stuck open thermostat, plugged heater core, faulty temp blend door actuator,
May be a defective thermostat or heater core