So I had my bunk heater serviced a few months ago because it would blow a lot of smoke and had difficulty starting up. Basically had all new parts installed instead of buying a new one which I should or did. Now the bunk heater works fine and fires up like it should but the air coming out the vents is luke warm. A few weeks ago it got hot like normal but now it’s back to only being luke warm and I’ll wake up freezing if the conditions are right. Any insight?