dash heater not working

[capt Frank]

My 1999 Newmar, Dutch Star side radiator diesel pusher on FL chassis seems to have a problem getting heat out of the dash. It has worked well in the past but seems to be problematic today. No heat from the dash, coolant level is ok, could it be an air block? What suggestions are out there?

Thanks in advance

capt Frank

[KSCRUDE]

You might check for a value on the heater hose that turns the hot water on and regulates the hot water flow. It may be cable controlled or electric. Or some coaches have the hot water flowing all the time and use a door system in the heater/AC box to get hot or cold air. If you can find the value feel the hose before and after the value while the engine is running and see if it is hot on both sides. If not you may need a new value or a new temp control switch on the dash.

[capt Frank]

Thanks, the hoses are cool at the front, and the valves under in the lines at the engine are open.