It is OK. There are at least 2 threads with your post. Have you set up your e-mail for your profile. You should get an e-mail for each thread you post into.
Appliances are similar across many RV brands and models. So make and model of the furnace will get us oriented to answer your question. Searching for the make and model on-line often turns up sources to replace parts and both installation manuals and operator's manuals.
Appliance manufacturer websites often have the same information.
Pictures of your issue also help. See the lower part of the "Reply to thread" screen under "Additional Options" / "Manage Attachments" follow the prompts. Often unexpected additional steps are required to finish uploading. Read the whole screen at each step the first time you do it.
is one responsible source for parts. There are hundreds of sites, most of them are good. Amazon.com has a lot of stuff you can find using make and model.
I wish you good luck and happy trails ahead!