New warranty policy from Grand Design

I suspect it's a solution without any problem to solve. I've NEVER been denied service from any RV dealer that sells the product I've having issues with. Water heaters, refrigerators, water pumps and many many other items in your RV are found in many different brands of RV and any of those dealerships can (and almost always will) work on them under warranty or otherwise. IF you find a dealer who will not do warranty work on those type of items you've likely found a dealer you don't WANT touching your RV because they're turning down good business. Problem is if they do shoddy work they would often have to do work TWICE or more times to get a problem fixed and most suppliers will only pay for the work to be done once.

If it's structural issues you're having (leaky roof or delamination of side walls or suspension, you may indeed need to go ONLY to the dealer of that particular brand for repair work. Dealer C sure isn't going to get paid by dealer A for fixing a roof that was put on improperly by the manufacturer.