The Aqua Hot is a pretty simple unit. BTW, that is NOT antifreeze, it's boiler fluid. Do NOT refill your reservoir with antifreeze. Anyway, the boiler fires and heats the fluid which in turn gives you heat inside your unit. Each one of those fans are separate from each other. Check to ensure each fan unit is functioning properly and getting fluid thru them. If it's an air lock, they should be able to easily bleed the system if they know what they're doing. Be sure, while they have it, that they service the nozzle assembly and also check the fuel pump pressure.
You said they've only had it since Monday. I think two weeks is a dealer minimum to keep your coach regardless of the 'fix'...:)....Dennis