I replaced the thermostat in the van but the vents don't blow out hot air. However the AC works.

Did you bleed the air out of the cooling system after replacing the thermostat? If not it will give you a no heat issue.

How do you do that. I started the van while putting the coolant in and waited for the bubbles to stop. Is that what your talking about?

Yes but did you have the heater on max heat? It is advised to turn it on high while bleeding the system. Did you have heat before changing the thermostat?

I had heat, but the thermostat broke and I had to replace it. After I replaced it, I didn't have heat so I replaced the thermostat again thinking it was a faulty part and still didn't have heat.

Ok you have air in the system. Try bleeding system again with the heater on max heat. Once you get all the air out you will have heat. If after bleeding the system again you still don't have heat feel the heater hoses going to the heater core in your dash. If one is hot and the other is cold then it is possible that your heater core is stopped up. Did you ever put any "stop leak" fix in a can stuff in your cooling system?

No, I don't use that stuff.

there's a little rivet in the thermostat that let's air pass one little bubble at a time....at the shop we'd snip these out with a dykes to leave a hole for air to get EASILY thru that...you may consider doin' this if air-bound now~...also some automakers are nice to give you a schroeder valve at the exit pipe of the heater core (the highest point) to let the air out easily with the engine off~

you all get "kudos" from the judge for just participating in this forum and puttin' a little MEAT on the bone....advise wise....for anyone who's researchin' this exact problem with this exact vehicle...got it man, you're a permanent part of automotive history....lots of these guys don't think of the permanance of what's bein' offered here...I for one am grateful to participate sharin' what I got with everybody~

Good evening judgeroy. Check your model for the valve that judge is talking about. I feel that your issue is air in the cooling system. Glad you don't use that stuff. They call it a fix in a can but really it's just more problems in a can.

it's Freakin Eighty degrees in Clearlake....like Minus 15 in Milwaukee....I love California...there's plenty of room for everyone...Clearlake has stars and moon...deer and hundreds of species of birdies including the comical Western Ground Quail...here and Oregon are the only places this paint-brush headed little guy is found~

Have you seen DavidH25...gifted him some Nueske's Landjaeger sausages and haven't heard a peep from him since...we used to communicate daily...I see he answers corolla questions...so he's still alive....wonder about that guy sometimes~

we'd simply take the top hose off...coolant went everywhere but the air came out...admittedly this was a disgrace....but got the problem solved....and NO parkin' on a hill ain't gonna do it~

Thank you I'd try that tomorrow. I hope after this, the heat will work. I'll let you know.

No ain't heard from him. Miss him on here. Good luck with bleeding the system. When you get all the air out you will have heat.

amazing how some etylene glycol and water 50/50 mix will get "crispy boulders" that stick and foul up an otherwise good thermostat and create WEAR on the waterpump...seasonal coolant flushes are paramount if you want to keep your engine clean~ I've recently discovered with the cold weather some cold-weather antifreeze and recommend it because is slightly "thinner" because it does not want to turn into ice very easily~

In addition to no heat, when I open the front driver side door, the interior lights do not come on. However when the other doors are opened, the lights comes on.

That's your door switch either dirty or faulty.

I am beginning to work in a shop, when you do a tire rotation do you have to balance the tires? If so, all the tires or just the front?

On just a routine rotation with no complaints of a vibration there is no need to balance the tires. If new tires all of them will need to be balanced.

Thank you, and the cooling system is still having problems so I am going to bring the car into auto school and let my teacher look at it.

Sounds good. Learn all you can we need a good group of mechanics to take our place as we get old and gray. Lol