The shut off, inline water valve, is not open....
Kinked heater hose, (No water getting to heater)...
Very low on engine coolant...
Water pump having problems getting the water to the Top of cab,
Thermostat stuck Open, Engine itself is not hot enough, to give you a good heat transfer at the heater, WHAT IS THE ENGINE TEMP READING?...
On my
L4200 cab... I block the radiator air flow, slip a piece of cardboard or rigid plastic sheet into the slot that was designed for the filter screen...
The engine will run at a better temp during the winter & the Heater will get you Very toasty inside the cab... KennyV
