I have a 2018 Thomas Safte liner with a rear engine Cummins . The last few mornings the driver is not getting any heat to the passengers . Last year we shut off two valves by the heater booster pump .What could I be missing ? The valves are turned in line . Is there another valve I am missing ? The drivers compartment is working but she said it's not as hot as last year . Thanks
Air bubble? Our Thomases are 1999's and older, but one of the heat valves is right on the engine block and the other by the boost pump. On a new one like yours make sure there isn't a dash mounted temperature control that goes to an electronic or cable valve somewhere inline.
Funny you should mention that . We do have a temp control that is electric . Where is the valve for that ?
Its in the front compartment where the blower motors are. Follow the copper pipes and youll see the valve with a little black plastic motor on it. Ive had to replace a few.
It can if its stuck shut. Or the motor fails after closing the valve. Remove the panel and get someone to cycle from full hot to full cold and you can see the shaft turning. Ive seen them fail both ways. Wither motor failed or broke, and/or the valve seized up.
It can control all heat because I believe the coolant is routed from the engine to the defrost heater core first, then the rest of the bus. Unless Thomas still plumbs the whole thing in parallel like on our '93 pusher. I'm not a mechanic, just a part time driver that has helped the mechanic occasionally.
I know I am being stupid but what panel and where ? I am not to familiar with this bus .So I need some more help and thank you all for your help I knew I could count on the replies !!! Thanks
In the front of the bus open the panel in the middle and look in the middle, there is a small piece that can slide up and reveal the cabin filter remove the screws holding the panel over the little one, be careful not all the screws have to come out some around the copper tubes will remain. Inside will be the blower motor assy for heat and defrost to the right, looking at the bus will be the heat valve. Check your lines to see if one or both are hot/warm have someone work the temp control knob and observe the movement of the heat valve, if no movement you may have a faulty control panel. They do go bad even on new units. If you have a sister bus try swapping one (one from a C2 is different). Let me know if you need more help.
Okay I opened the panel in front outside . I see the lines going in . One is cold and other is hot . I looked at the dash and it is all one piece . So I would have to remove the dash ? This is a rear engine Thomas . Thanks
This is a common valve failure in the HDX heating system. You can contact Schetky or Freightliner NW and get the valve assy. It's kind of a pain in the butt to change but its the only fix. If a driver tries to change the heat it can get stuck closed again since its an electric valve. Good luck
A double-ended hose barb and 2 hose clamps fix our Blue Bird electric valves every time! Not sure if that would work on this particular application since I haven't had the pleasure.
Thomas no passenger heaters ???
Posted - 09/24/2018 : 09:51:25 AM
