marginal heat 85 300D

[tobybul]

First winter for me on my 85. Heat is very marginal. I have checked most everything and considering the low miles and "newer" age of the car, I believe the CCU is fine. I know the aux pump is working and so is the mono valve. Just for kicks I disconnected the monovalve and it did not improve the heat. In fact its better when its connected.

I am wondering if the thermostat may be reversed. The temp gage show good operating temp consistently (90c). Thanks for any input.