# Thermostat

**URL:** <https://community.cartalk.com/t/thermostat/59704>\
**Category:** Maintenance/Repairs\
**Tags:** chevrolet, s-10\
**Created:** [January 8, 2011, 4:46pm UTC](https://community.cartalk.com/t/thermostat/59704 "2011-01-08T16:46:22Z")\
**Posts on this page:** 9\
**Page:** 1

<div class="post-metadata">

**Author:** ![sheridan](https://avatars.discourse-cdn.com/v4/letter/s/b782af/32.png) [@sheridan](https://community.cartalk.com/u/sheridan)\
**Post date:** [January 8, 2011, 4:46pm UTC](https://community.cartalk.com/t/thermostat/59704/1 "2011-01-08T16:46:22Z")

</div>

why have i had to replace the thermostat 7 times and my heater still doesn"t work? I have only put 61000 miles on the vehicle.

---

<div class="post-metadata">

**Author:** ![jesmed1](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/jesmed1/32/2097_2.png) [@jesmed1](https://community.cartalk.com/u/jesmed1)\
**Post date:** [January 8, 2011, 4:51pm UTC](https://community.cartalk.com/t/thermostat/59704/2 "2011-01-08T16:51:25Z")

</div>

Have you checked any other possibilities, such as a broken heater valve, blend door stuck closed, or air trapped in the heater core?

---

<div class="post-metadata">

**Author:** ![the\_same\_mountainbike](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@the\_same\_mountainbike](https://community.cartalk.com/u/the_same_mountainbike)\
**Post date:** [January 8, 2011, 4:53pm UTC](https://community.cartalk.com/t/thermostat/59704/3 "2011-01-08T16:53:59Z")

</div>

Why? Because you’ve been changing the wrong part.

Can you explain better?

---

<div class="post-metadata">

**Author:** ![common-sense-answer](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/common-sense-answer/32/716_2.png) [@common-sense-answer](https://community.cartalk.com/u/common-sense-answer)\
**Post date:** [January 8, 2011, 5:13pm UTC](https://community.cartalk.com/t/thermostat/59704/4 "2011-01-08T17:13:25Z")

</div>

State The Model-Year Of This Vehicle.

Who has put in 7 thermostats ?  
What brand are they ?  
After thermostats 2, 3, 4, 5 , and 6, did anybody have a suspicion something was a bit odd ?  
What other diagnosis of “no heat” has been done ?

CSA

---

<div class="post-metadata">

**Author:** ![sheridan](https://avatars.discourse-cdn.com/v4/letter/s/b782af/32.png) [@sheridan](https://community.cartalk.com/u/sheridan)\
**Post date:** [January 8, 2011, 7:34pm UTC](https://community.cartalk.com/t/thermostat/59704/5 "2011-01-08T19:34:50Z")

</div>

once i replace it with a new thermostat the heat starts working fine.but but not long after it stops blowing warm air.

---

<div class="post-metadata">

**Author:** ![sheridan](https://avatars.discourse-cdn.com/v4/letter/s/b782af/32.png) [@sheridan](https://community.cartalk.com/u/sheridan)\
**Post date:** [January 8, 2011, 7:40pm UTC](https://community.cartalk.com/t/thermostat/59704/6 "2011-01-08T19:40:27Z")

</div>

no,it diagnosis faulty thermostat every time.

---

<div class="post-metadata">

**Author:** ![common-sense-answer](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/common-sense-answer/32/716_2.png) [@common-sense-answer](https://community.cartalk.com/u/common-sense-answer)\
**Post date:** [January 8, 2011, 8:11pm UTC](https://community.cartalk.com/t/thermostat/59704/7 "2011-01-08T20:11:14Z")

</div>

I Wouldn’t Blame That Bunch Of Thermostats.

Sounds like you’re getting air in the cooling system. When you open it up to change thermostats, you’re purging the trapped air (Thermostat housings are ussually near the top of the cooling system and air rises in liquid).

After a couple of drive cycles, you’ve got air surrounding the thermostat. Then, no heat.

You need to find the source of air entering the system. The system is supposed to be a closed loop. Your loop is open.

A cooling system pressure test is a start in the right direction.

Are the radiator and coolant recovery tank always full to normal capacity when you check them after “no heat” begins ?

CSA

---

<div class="post-metadata">

**Author:** ![Rod-Knox](https://avatars.discourse-cdn.com/v4/letter/r/a183cd/32.png) [@Rod-Knox](https://community.cartalk.com/u/Rod-Knox)\
**Post date:** [January 8, 2011, 8:42pm UTC](https://community.cartalk.com/t/thermostat/59704/8 "2011-01-08T20:42:07Z")

</div>

Reinstall the current thermostat with a bead of RTV in the slot that the thermostat rests in along with a new gasket.

---

<div class="post-metadata">

**Author:** ![oldschool](https://avatars.discourse-cdn.com/v4/letter/o/e19adc/32.png) [@oldschool](https://community.cartalk.com/u/oldschool)\
**Post date:** [January 8, 2011, 9:35pm UTC](https://community.cartalk.com/t/thermostat/59704/9 "2011-01-08T21:35:06Z")

</div>

I kinda shake my head with thermostat replacements. For many cars they are so cheap that you might as well go ahead and replace them. They are also so simple I really don’t understand why they get replaced so much (perhaps because they are so cheap) but I bet many are “A OK”. Now BMW has a “feedback” thermostat and at times it sends the wrong data, perfectly good functioning thermostat but fails in an electrical sense. People sure get told to replace thermostats of all types quite a bit.
