Hello AMW, welcome to irv2.com!
In order to receive knowledgeable help, we must know the brand of the furnace in your RV. This website
http://www.aerocoachinc.com/ownManual.php
Contains an extensive file of pdf operation and service manuals for a wide variety of RV appliances, and other vital components.
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2000 Winnebago Ultimate Freedom USQ40JD
, ISC 8.3 Cummins 350, Spartan MM Chassis. USA IN 1SG 11B5MX,Infantry retired;Good Sam Life member,FMCA.
" My fellow Americans, ask not what your country can do for you, ask what you can do for your country. John F. Kennedy