no heat on 1991 Chevrolet G Series Van (G20)

heater blows cold air when turned on.

Get Your Car Fixed at a RepairPal Certified Shop.
We certify shops based on expertise, quality work, and verified customer reviews
3 answers
I noticed mine blowing coldish on the feet only this winter when I took it for a trip.
could be heater control valve located just in front of heater core
themostat stuck open or heater core plug