check your antifreeze and water...maybe water pump too.check for a thermostat that is not closing ,.in other words a faulty thermostat
One reason your home electric heater is blowing cold air is the heating elements are burned out. A bad thermostat may also be the problem.
check the coolant level, or, possible stuck thermostat.
This is caused by low coolant levels in most instances.
Depends on your location.
Call a heating specialist. Heaters are too dangerous for amateurs to fool with. There is danger of fire and, in the case of gas, asphyxiation if they are not properly repaired and adjusted.
Over-obvious answer? Your radiator, or one of your radiator hoses, leaks - badly.
It is because your heater is having to heat up so its blowing cold air out while its heating up.This means your heater is not very efficient and it needs to be checked.
The most common reason the heater is blows cold air on a 1999 Ford Winstar is a bad thermostat or blocked heater core.
Your cooling system is empty of coolant and you must have a large leak somewhere.
It's probably the radiator. Make sure there's enough coolant in the radiator.
That is exactly how a heat pump works in heating mode are you sure it's not a heat pump?
The electric heating elements are probably turned on.