Perplexing Furnace Problem
Dear RV Doctor:
I was intrigued to read the letter from Mike Tobias in the August 2015 “House Calls” column (page 20) about lack of heat in his 2014 Tiffin Phaeton equipped with two furnaces. We have the same problem in our 2015 Itasca. Our two furnaces fail to work when the temperature is in the mid-30s or below. This has happened on a number of occasions, and the dealership has been unable to determine the cause. Technicians changed the propane regulator, but a trip to the Canadian Rockies, where we again experienced low temperatures, proved the regulator was not the issue.
I have narrowed the possibilities to the propane system, because when the furnaces fail, our propane water heater and the cooktop do also. I have discovered that by using a hair dryer (no naked flames) to gently warm the area around the output of the regulator, I can restore the propane flow and then the furnaces will work for a short time. It seems the area that freezes is near the output of the regulator and the short, flexible hose that runs from the regulator to the main rigid propane piping. That hose looks to be a small bore, and I wonder if that might be the cause, or maybe there is some kind of venturi effect where the propane enters the hose, causing supercooling. Any thoughts would be greatly appreciated.
Nick Hodson, F438637
Salt Spring Island, British Columbia
Since you’ve experienced operational problems with more than just the furnaces (great job troubleshooting, by the way), it leads me to believe the issue is appliances (specifically the furnaces) outrunning the rate of vaporization of the propane system; therefore, the demand for propane is higher than what the system actually can deliver. This is called “container refrigeration.” It happens often in cold climates.
You are spot-on that the area around the propane tank service valve and regulator should be kept warmer. If the problem persists, and you have 120-volt-AC electric available, run a 100-watt trouble light to the area inside the propane compartment and position it near the junction of the regulator and service valve. Make sure it’s not just a bare bulb resting on a flexible rubber propane hose. Keep it illuminated the entire time while parked in those cold temperatures.
If you are worried about the bulb breaking, an alternative is to use one of the commercially available 120-volt pipe-warming tapes that can be found at most hardware stores. They come in various lengths and usually have a built-in thermostat, which saves on electricity. The added heat might warm the liquid propane enough to allow it to evaporate with enough expediency to keep the appliances running.
If you have an electric option on the water heater, use the electric element instead of propane to heat the water. And try to avoid cooking while the furnaces are operating.
Another suggestion is to not run both furnaces at the same time. Perhaps alternate them so that the propane system can keep up. Also, and most importantly, during cold-weather RVing, always keep the propane tank filled to above 50 percent capacity. In fact, if at all possible, I recommend keeping it filled to its 80 percent maximum capacity whenever the furnaces are needed. I touched on this topic in a December 2015 article in FMC (“Furnace Maintenance,” page 48).
Finally, if you suspect your American Society of Mechanical Engineers (ASME)-certified tank might contain commercial butane rather than propane, it may be a good idea to have a supplier purge what is left in the tank, add a moisture-drying agent, and refill the tank with the correct blend of propane for winter use.
Chalky Fiberglass
Dear RV Doctor:
I read your recommendation regarding roof cleaning in the July 2015 issue (“House Calls,” page 24), but my question is a little different. I have a 2007 Winnebago with a fiberglass roof. I get up there three to four times a year to clean it, so I do not have a mildew problem. However, I have a chalking problem. Is there anything I can apply to seal the roof and stop the chalking?
My coach is black and silver, so when the rain washes the white from the roof down onto the front and sides of the coach, it does not look pretty, and then I have to wash it again. I tried to use a spray-on wax, but that is not a great idea because it causes a slippery condition. It is bad enough getting up there with a ladder; I don’t want my exit to be without one!
Jim Stoodley, F389890
Hollywood, Florida
It’s quite common for just about all types of RV roofing to oxidize over time, including fiberglass and rubber. To combat this normal occurrence, a roof requires periodic maintenance. Keeping it clean is the best thing, which you are already doing.
For fiberglass oxidation and chalking specifically, I’ve had great success for many years with Protect All’s Fiberglass Oxidation Remover and Color Restorer. Most RV accessory stores carry this product, and it’s available online as well. I recommend it for dull, faded, chalky front and rear caps, although it works fine on any fiberglass component.
I do have to warn you, though. Since the product removes an actual layer of the finish and then polishes it, the roof will be slick, so take extreme care should you opt to perform this yourself. Personally, I believe this would probably qualify as a great sublet job! But it will indeed remove that chalkiness and will last probably for a couple of years under normal care and use. Plus, you can use it on the front and rear caps.
That said, if you truly like your coach and will be keeping it for a while, I also highly recommend the RV Armor roofing system. It is a one-time-only, guaranteed-for-life RV roofing system that requires zero maintenance, period. You never have to get up on the roof again. For more information, visit www.rv-armor.com.
LED Is On The Blink
Dear RV Doctor:
I recently installed a 12-volt LED lamp on the exterior of my coach. The only problem is I can’t get it to work when the unit is plugged in to 120-volt electricity. I’m thinking somehow it’s not going through the transformer. I even tried tying it in to a light that I know works while the coach is plugged in. Any ideas?
Clint Brandon
Via Email
The converter, while connected to 120-volt shore power, typically produces the DC voltage for all the low-voltage circuits, so be sure that lamp is wired to the output side of the converter. And just as important, the negative connection must ultimately terminate at the frame of the RV. If the converter is not bonded to the frame, or the negative DC conductor from the lamp does not have a good, solid ground connection, it could result in an open circuit.
Remember, with DC electricity, the “open” could happen on the positive or the negative side of the circuit. If you’re sure you have good positive 12 volts DC at the lamp, be equally sure you have a good negative connection as well. If that lamp works when on battery power (not plugged in to shore power), then I’d look closely at the negative connection between the converter and the frame.
Also, be aware that some LED bulbs and lamps must be connected with correct polarity. Check the brand of the new LED lamp and see whether it requires a certain polarity at the positive and negative connectors. There are some other electrical anomalies to consider, such as AC voltage ripple, etc., but that gets us deeper in the weeds. Start by verifying the voltage and polarity requirements of the new lamp and be sure that the circuit feeding it is compliant with those requirements.