Combines 2188 Cab Heater Not Working

We had the same problem a few years ago on our 2188- the valve under the cab was clicking and didn't let the hot water into the heater core. Replaced the valve and cured the problem.

We had the same thing happen twice on a 2166. As roster said the valve in the buddy box is the problem. It opens and closes as you adjust the heater knob. The valve drive has plastic gears in it and they strip. The valve comes as an assembly. We removed the drive from the new valve and put it in the old valve. This can be done with out breaking the water lines in the buddy box and getting water in the cab.

I've done the same thing. It saves a mess! It's probably no harder to accomplish either.

I've been through the same thing. It just occured to me that my valve went bad right after I change coolant. Does anybody know whyIJ