6.0 Excursion heater fails when stopped

[Layson]

6.0 excursion blows cold air from the heater when stopped at a light or just sitting...any idea why?

 

[Layson]

Well as soon as I post this they checked the coolant and it was low. Topped it off and good now!

 

[dmd]

Coolant low.... Check the egr valve if you still have it, could be cracked..

From the photo it looks like you probably have it modded, but a 6.0 low on
coolant usually means trouble.

 

[DEEZUZ]

head gaskets