You have a bad thermostat. It is a cheap fix (3-9$) in most cases, and fairly easy.
The most common reason the heater is blows cold air on a 1999 Ford Winstar is a bad thermostat or blocked heater core.
What do you mean by "has no heat"? No air blowing out, blowing out cold air when heater is on, blowing nothing at all? Heater not turning on? What specifically is happening?
faulty control valve on heater or air in the lines
Low coolant and a clogged heater core are possibilities.
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.
Low coolant, stuck thermostat, blocked hoses.
You may need to replace your Thermostat or your Heater Core.
If you are saying the heater is blowing out cold air you need to change the heater core which is located inside the dash
Your heater may be blowing cold air because there could be a problem with the thermostat, a lack of fuel or a clogged air filter. It is recommended to check these components and consult a professional if needed.
Low coolant? Defective thermostat? Heat control cable not adjusted properly? Heater core plugged or airbound?
Check to see if you pilot light is lit
because u pooped in it