The heater hose ball valves are the cheapest solution to this problem. The valves sure improved ours. The problem, as I understand it, is caused by the radiator/condenser being too close together to allow proper air flow. Neither Workhorse or my RV mfg will take responsibility and fix it. Of course, if you want to spend a bunch of money, either will be happy to install an upgrade A/C kit to make it work as it should.