Re: Ranco H 16

Posted by HH56 On 2015/2/22 0:03:38

Apparently Packard found that inside the box didn't work well with the thermostats they were using. When they introduced the thermostatic valve in 48 the bulb was inside the plenum sensing nothing but the heated air. Shortly after the 22nd series intro they said that location was not satisfactory and had dealers remove the bulb from the heater box and place it under the glovebox so it could sense ambient air (Dec 1, 1947 Service Counselor). They specifically told the mechanic to make sure free air could circulate around the bulb. In the units from 24th series on they used a different valve. It was placed next to an opening in the plenum and heated air was directed to blow past the sensing element. I guess they figured that was the best way with that valve so it could sense both ambient air and also monitor that the heated air was not too hot