Clear Unsightly Surfaces and Fix Furnace Failures

RV advice from April's Mark My Words monthly column

March 31, 2019

Mark Nemeth

Hi Mark My Words readers! This month, we’ll cover decal removal, stains, leaks, furnaces and fridge issues. I hope you’re out there enjoying some great spring RVing. Remember to send your RVing questions to [email protected].

Hi Mark,
We have an older Montana fifth wheel that has many of its decals peeling. Is there an easy way to remove these decals entirely?

Hi Barry,

Removing the old decals is a difficult task and may be best left to professionals. There is no miracle solvent or tool, but if you have near-infinite patience and a heat gun, you can remove these unsightly coverings with a steel scraper, some heat and a gentle touch. I’ve also heard that you can buy a tool called an eraser wheel. You can purchase one at O-Reilly or Napa stores. It mounts to any drill and is a round wheel that is made of a material like a clear eraser. It’s designed to remove a decal and not harm any finish. Regardless of how you remove them, you’ll find that the paint or fiberglass underneath the old decal is almost inevitably going to be a different color because it hasn’t suffered exposure from the elements. So, remove one decal from a less conspicuous area and see what you think before you attack the whole rig. An alternative approach is to develop a blind spot and just not see the old decals. That approach has worked well for me in the past!

The closet in the bedroom of our fifth-wheel gets wet in one corner when it rains, and the water seeps through the whole carpet. The closet is a slide-out. There is no moisture on the walls, and the problem area has been re-caulked by my husband and a repairman, but it continues to get wet when it rains. There is no obvious crack in the slide. This is the second year we have had this rig and did not have this problem until now. The repairman and my husband both thought initially it was condensation, but then the repairman agreed with me that it is too wet to be condensation. We are staying in the southern part of Northern California. It is quite cool at night and then warmer in the day, but I have not found any other issues with moisture.
Any ideas? Thanks,

Hi Connie,
I agree that we can pretty much rule out condensation. You have a leak somewhere, and the evidence is appearing in the closet, but the actual leak could be some distance away. Water tends to travel once it enters the RV’s structure, so you need to examine the entire slide very carefully for any place that water could be getting in. Sometimes, the crack or opening will be very subtle and hard to find. It is also possible that the water is actually entering somewhere else and is running into the slide area from some other part of the roof or sidewall. Don’t rule out an internal leak source, either. A small drip at a plumbing connection could be the source of the water you see. I agree that a plumbing leak is unlikely, but still worth investigating. If you are unable to find the cause of the problem, some RV shops have the ability to mount a powerful blower on the RV, seal any vent and window openings, and basically pressurize the inside. Then a soapy water solution is sprayed on the outside of the RV and bubbles will appear anywhere there’s a leak. Sometimes this is the only way to find the really sneaky ones. Good luck in your search!

Hi Mark,
I have brown spots on the underside of my awning. I tried different types of cleaners but have had no luck. Can you help?

Hi Gary,
It depends on whether those brown spots are dirt or mildew on the surface of the vinyl, or if they are stains in the vinyl itself. Mix up some dish detergent and warm water and add a little chlorine bleach. Use a brush, a Dobie pad or other plastic scrubber, and give a small area a good scrubbing. If the spots don’t come off then, they’re probably stains. It is very difficult to get stains out of vinyl, but you can try a marine vinyl cleaner like Z-care or Moldzyme, available at most boat shops. I have had some luck with OxyClean mixed with a little water to make a paste. Apply the paste to the stain and let it sit until it dries. You can get OxyClean at Walmart in the laundry detergent aisle. As a last resort, try a Mr. Clean Magic Eraser or SoftScrub (Walmart again). These are abrasive, so be gentle and test a small area first. You can help prevent stains on any awning by following a simple rule: never roll it up if it’s wet. If you must roll up a wet awning, unroll it as soon as you can and let it dry before re-stowing it.

I have an Arctic Fox camper and noticed that one of the Bungie cords holding the roof covering in place has rubbed some of the white paint off the door holding the batteries. It’s just one small spot, the size of a quarter. Just wondering what’s the best method of getting that spot painted to match the rest of the coat. I’m not sure if it is a specific color of white, or whether it is a glossy or flat type of paint.

On another topic (same RV), we’ve noticed on some occasions that when we turn up the thermostat inside the camper, the furnace fan comes on. Sometimes it produces no heat and just continues to blow cold air. Sometimes, no amount of off/on with the thermostat seems to correct the situation, and the next time it will come on just fine. I never know if it’s actually something regarding the furnace, or if the propane just hasn’t gotten to the burner area?

It does seem that when the camper isn’t used for long periods (even with the stove), air must get in the lines, as it takes a bit of hissing from the stove before it will light. Thus, it’s not a simple procedure to see if propane has gotten to the furnace burner significantly enough for it to fire up. Perhaps you could explain the procedure on the newer RV furnaces, as I understand there are several checks they go through before they will fire. I still don’t know if this might be a situation of propane not getting to the burner or if there is a fault in the furnace itself.
Thanks for anything you can provide,

Hi Dale,
Let’s talk about the furnace first. RV furnaces are not real smart: if they fail to light the first time, they enter lockout mode, which means the blower will continue to run with no heat being produced. Just turn the furnace off at the thermostat, wait a moment, then try it again. In a rig where you haven’t used the propane system in a while, you may have to go through that cycle several times before the furnace will actually light and produce heat. That’s because it can take a while to purge out the propane line to the furnace. Now, if the furnace fails to light intermittently, even when the gas supply has been on and in use for a day or more, then there may be a problem developing with the furnace itself. Let’s review the sequence the furnace goes through when starting.

When we turn the furnace on, usually by setting the thermostat to ask for heat, the first thing that happens is the furnace receives a 12-volt signal from the thermostat, and the fan blower relay closes, and the blower will start running. Normal airflow will cause a sail switch inside the furnace to close, sending power to the circuit board. The board will open the gas valve after about a 15- to 30-second delay, and the electronic igniter will begin to spark. If the flame lights, the board senses “flame lit,” and the furnace will run and produce heat until the thermostat is satisfied. Furnace shutdown starts by the loss of the 12V signal from the thermostat. This removes power from the circuit board, closing the gas valve and extinguishing the flame. The blower relay (time delay) stays closed for about an additional minute before it opens, shutting the blower down.

The circuit board in the furnace monitors several things to ensure that everything is working properly. If anything happens to make the circuit board unhappy, the furnace enters lockout mode, which means the gas to the burner is shut off and the fan will run forever, or until you shut it off at the thermostat. If this intermittent failure to light continues to happen, and it’s not obviously related to the propane system being shut off, then it is probably best to have the furnace checked out by a tech. If you are comfortable working on the furnace yourself, then here’s a good furnace troubleshooting guide:

OK, the paint problem: In my experience, it is almost impossible to color match, paint and feather a small damaged area yourself and make it look like new again. Have you considered covering the spot with something like a small decal or sticker? Can the door be easily removed? Repainting the whole door is actually way easier than trying to fix a small blemish in the existing paint. You can paint it yourself with a rattle can, but you may need to experiment a bit to find an off-the-shelf color that is close enough to original to look good. The only alternative would be to take it to a paint and body shop, but I think the price tag on that will be pretty high.

Hey Mark,
I have an older Golden Falcon fifth-wheel, and at the end of last season, the fridge froze up. I got solid ice buildup on the fins in the fridge, as well as on the freezer’s back wall. Could this just be an issue with the thermostat, or should I look at replacing the fridge?

Hi Brad,
Take a look at the fins inside the refrigerator compartment. Some fridges use a small sensor (a thermistor, actually) on the fins to monitor the cooling system temperature. If that little sensor falls off the fin, the cooling system will run continuously, causing all your food to freeze. Just clip the sensor back onto the fin, and you should be good to go. If you don’t have a wayward fin sensor, then the most likely culprit will be the refrigerator control board or its temperature sensor. If your refrigerator is original equipment and is getting on in years, I wouldn’t spend too much on repairs, because in my experience, most RV absorption fridges don’t last much longer than 12 to 15 years. Given that reality, a replacement fridge may be more cost-effective than repairing yours.