Dash heat control

[az bound]

I had a problem with the dash heat control and after doing some research and testing I was able to resolve the problem. Want to share it with others whom may have the same symptoms. I could not control the temp. of the dash heat (all or nothing).
The system on my Airstream (WH chassis) has a potentiometer on the dash temp. control, which in turn controls a valve controling the flow of water through the heater core.
For a troubleshooting guide and parts go to www.evanstempcon.com I hope this will help others with heat comtrol problems.

[JCM]

They have a "hard" controller that looks the same but adjusts a cable which will operate a ball control valve. It gives a more positive control over your temp and has a faster reaction time.

[oemtech]

This has been hashed over a number of times. One thing I found out was that the Evans valve is not desgned as "blend" type valve. Read this Thread for more info.

[az bound]

Dale; Thanks for the thread link. I had to replace the valve and thought I would share info with others. Hope the new one lasts longer than 4 years.

[JCM]

I read the thread but don't understand why it is not a blend valve. I have one in my hand and it has a ball +opening like the electric model. If I open or close it a little that would allow more or less water through blending with the other source. Looks the same as the electric one (down the hole) but doesn’t have 50+ gears. The dash replacement controls the pull-push cable to the ball valve.

[oemtech]

I can confirm that the Evans valve does not act or react like my Honda's temp control. On my Honda the change in temp is almost instantaneous and takes awhile on my my motor home.