I agree with them also. On a different thought, install a water valve on the heater line. I get them from Lowes in the plumbing section with the barbed ends cast into brass the ball valve and splice it in the line. Been doing this for years because the heater valves that comes factory let's a little hot water circulate even when off. Check your hose and see. Both my Suburbans are done this way and the 96 was cooled down 12 degrees at the AC vent! Valve and two clamps about $10.00, cooler air out the vents, Priceless!
