Winter is coming and I’m new to these older vans. Here’s a weird one. When on “heat” mode, low/no air comes from the vents regardless of fan speed.

-AC blows cold and responds to fan speed
-Vent blows warm and responds to fan speed on “vent” mode
-Defrost works well
-van runs cool on temp gauge (never over 1/4 up)
-heater hoses hot
-heater core replaced/system flushed a year ago (previous owner)
-upper radiator hose cool/empty feeling
-coolant topped off
-new radiator cap
-recent water pump (previous owner)

I’m thinking thermostat, but shouldn’t the vents be blowing air at me in heat mode?


Jason
2008 Ford E-250 4x4
1984 Chevy G20 5.3L/4L60E (SOLD)