Heater randomly works

[775TSI]

Ok so this is mainly referring to my wifes Acura but my car does it as well.

Heater does not work (blows cold) on park and neutral, when given gas the heater picks up and works great. Any idea?

 

[2point3Tsi]

Low coolant , thermostat stuck open or plugged heater core

 

[775TSI]

Well checked everything and low and behold shes out of coolant. But still doesnt explain why mine does it too. I spend every hour on my car i have no leaks and my coolant is always checked. Really odd, must me a core.

 

[troppo loungo]

Could also be your heating controls not letting coolant to the core or a stuck damper. Does your A/C work?