Heater control valve
Thread Starter
Instructor
Joined: Nov 2020
Posts: 145
Likes: 48
From: France (Britanny)
Heater control valve
Hello everyone 
On my 86, my heater control valve has no movement, so it stays closed. I have no heat in interior.
However, I can move the valve manually, but it's too hard to be automatically activated I think !
By turning it manually, I have some good heat.
1- When is this valve open or closed ? (I think closed when air conditioning is on ?)
2- Can I let it always open, knowing that I've no air conditioning anymore ?
Thank you
Chris.
On my 86, my heater control valve has no movement, so it stays closed. I have no heat in interior.
However, I can move the valve manually, but it's too hard to be automatically activated I think !
By turning it manually, I have some good heat.
1- When is this valve open or closed ? (I think closed when air conditioning is on ?)
2- Can I let it always open, knowing that I've no air conditioning anymore ?
Thank you
Chris.
Instructor
Joined: Dec 2016
Posts: 241
Likes: 77
From: Arlington VA
Yes you’re right. You can just leave it in the on position for the winter. It closes completely when the a/c is on but doesn’t stop the a/c from working, just reduces how well it works. Did that for a year or so till I repaired it.
Instructor
Joined: Jun 2019
Posts: 147
Likes: 48
From: Rockland County, New York
1. The valve is normally closed and only opens when you call for heat.
2. It can stay open always. You will just have coolant always circulating into the cabin heat exchanger.
Funny because mine would always spring closed. Only opening from vacuum. It was super easy to fix. Here's the thread I followed to fix it. https://www.corvetteforum.com/forums...-corvette.html
2. It can stay open always. You will just have coolant always circulating into the cabin heat exchanger.
Funny because mine would always spring closed. Only opening from vacuum. It was super easy to fix. Here's the thread I followed to fix it. https://www.corvetteforum.com/forums...-corvette.html
Last edited by bartenderfloyd; Nov 13, 2021 at 02:12 PM.
Drifting
Joined: Jan 2005
Posts: 1,354
Likes: 325
From: San Antonio Tx
Starting in 88 they didn't install these valve anymore while everything else in the heater system stayed the same. Many, including me, have removed the valves with no noticeable effect while in cooling mode. So yes you can permanently block it open with no problem.
