It's certainly not the cost of your motor home causing problems but it might be the unit you installed. I can't say as our convection / Microwave does nothing like you describe. We could not be happier with our oven and use it almost everyday as full timers (Cracker Barrel is not an option). We have had several, as a matter of fact, and they have all worked perfectly. We started with a Sharp which was impossible to replace when it died so we bought an GE Advantium which never cooked as well as the Sharp and eventually replaced it with a GE Profile which has been great and cooks even better than the Sharp. We have been living in this RV for going on 18 years and the oven has always been a major player in our dinners including Christmas Turkeys and Thanksgiving Roast Prime Rib. Yum!