Well...they are VERY important. Ask me how I know...
So, assuming you asked, when we bought our new RV we wanted to put them on, seeing the wisdom of spending just a little bit now to protect our RV.
But...the store, we went to buy them only had one for our refrigerator and not for our furnace. With so much going on (settling into RV life for the first time) we completely forgot about the missing furnace mesh protector.
Why didn't I just go to Amazon and order them...
Here are a few Amazon links to mesh covers. Be sure to measure to make sure you get the right ones.
Furnace and Water Heater
Fast forward a few years...and you guessed it, we had a problem.
I noticed a black soot coming from our furnace. We were going into winter and this was not good!!!
We called a RV mobile technician and something (wasps or possible a mouse) had crawled up into our furnace and made a nest and/or died up there in enough quantity that we had a big problem.
Our furnace got so hot that the metal discolored and it blew a hole in the metal to boot! I'm pretty sure if this had continued without us noticing we could have had a fire and lost the whole RV. So, I am extra thankful that we caught it before something tragic happened.
We had to completely replace the furnace and we're about to have a $1500 hit to our savings.
What to do...
Somehow, I thought to call our RV insurance company just to see if they cover such things. The lady who answered put me on hold while she asked someone else. I really didn't have hope that they would, but as the saying goes, "Never say, no for them."
Turns out, because we had comprehensive insurance it could be ruled an act of animal they covered the new furnace (minus of course our deductible.) Yipeee!!!
We were so relieved! Now, I don't know what your deductible is, but as happy as we were not to be paying for the whole furnace we sure were kicking ourselves that we hadn't tracked down a furnace vent cover sooner!
Now, that's all the money side of it, there's also that winter was upon us. Thankfully, it was a very mild winter where we were, but there were delays, after delays, after delays getting the furnace from the factory and let me say that electric blankets just can't be over-hyped enough in such situations.
So, the moral of the story is and what we've now done is buy every mesh vent cover that we can get our hands on.
Because I do not want to be responsible for your RV here is a disclaimer: This information is just what I do. If it would damage your RV please don't do this. I am just a fellow RVer like you trying to figure this stuff out and not a chemist or a professional anything to know what could or could not hurt your RV.