i changed my therostat. my heater still COLD, no HEATER. What could be the problem?

Question

my vehicle is a 1997 Ford Expeditions.

my heater does not have a raditator cap, so it must be closed system.

Dodgeman where is this temperature switch located?

Answer 1

first make sure the engine is coming up to proper operating temperature. what does the temperature gage say. if the engine is up to proper temperature, feel the hoses going to the heater. if one is hot the other cold you have either a plugged heater core, or a bad radiator cap not letting the coolant circulate properly. if the engine isn't heating properly you put in a defective thermostat.

Answer 2

If you changed the thermostat to correct a heater problem, that might not have been the solution. If you changed it & now you have that problem, chances are, you did not properly burp the system or relieve all of the air out of the system. To do this, I usually put the heat on max and run the vehicle with the reservoir cap off or radiator cap off until the heat blasts out of the vents. I know at that point that the air has been purged. It may spill over out of the radiator so at that point, I leave the reservoir cap off until heat comes out of the vents.

I'm thinking there is a problem with your heater control valve not allowing the coolant to flow into the core. I would need more information about the vehicle to give you a better diagnosis though. I have an Alldata setup at my house that I use for my business so I can pull up just about anything.

Answer 3

First are you sure you installed the thermostat correctly and if so are you sure it wasnt stuck in the open position when it was installed ? It is not uncommon to get a new thermostat that does not work properly. Also get someone to work the heat controls while you look to make sure the heat control valve is working and the transition flap for the heat/cool system is opening and closing.
You should check the the heater hoses to make sure no one has by passed the heater core, if they have then reconnect the hoses to the core. If everything apears to be in working order and you still have no heat then disconnect the heater hoses from the heater core and take your garden hose and flush the core out, Hold your hose to the outlet side of the core first and let the water flow out of the inlet side for 5 to 10 minutes then reverse the process by flushing from the inlet side. Make sure to start with the outlet side first because if the core is stopped up and you start from the inlet side first you may push the clog further into the core and then be unable to flush it out. Most times this solves the problem, if red looking water comes out of the core dont worry, it is just the rust and sediment coming out that has the core plugged up, continue flushing until only clear water comes out of the core

Answer 4

Either you don't have a sealed system due to leaks or your radiator is low on fluid. Check your heater lines and the shut off valve to make sure it's open allowing engine coolant to flow through the heater core.

Answer 5

i own a repair shop ,,and you need to make sure the coolant is circulating good through out the engine,if its not it will not put out any heat on it,also there is the temperature switch that could be bad,this is what takes it from hot to cold,and yours may be stuck in the cold position on it,i have seen a few of the expeditions do this ,before,check and see if it has the heat control switch that mounts in between the line ,and see if it is stuck,good luck i hope i hope this help,s.

Answer 6

I have the same problem with mine I replaced every cooling component but the problem persisted. I finally found out that the heater core was plugged up and water could not go through it. $600.00 repaired the problem.

Answer 7

vent ? heater hoses connected? did any one by pass the heater core because of a leak ?