|
|
RV Doctor ColumnRV Doctor #274 Hello Doc, we live in a fifth-wheel year round and supplement our gas furnace with small electric heaters to prevent the LP furnace from running too much. Even with that I have to replace the electrode assembly about twice a year (the old one is very burnt and crumbly when I take it out). Is this normal? I have asked others living around us and they don't seem to have to replace the electrode but every few years. What's up? Ron Shepherd, (East Hampton, CT) Ron, without even knowing what brand or model furnace you have in your rig, it's safe to say that it is not common for electrodes to deteriorate twice in one year. Indeed there is something amiss. First, check the delivery line pressure of the LP. All LP appliances are designed to operate at an optimum pressure of 11.0 inches of water column. Have a qualified tech check the pressure using an accurate manometer. Also, read through the literature for your furnace to see if there is a primary air adjustment on the main burner. Apparently the mixture of LP and air is not quite right. Some furnaces do not have this adjustment so the pressure and cleanliness of the orifice and burner are most crucial. In any event, the flame should be mostly blue in color with some tinge of orange. A dirty orifice and/or a dirty burner assembly will always contribute to improper combustion. Additionally, the gap spacing between the probes is also important as is the position of the entire assembly in the furnace. Your electrode assembly probably has three probes. The spacing between the center ground probe and the flame sense probe, (the one with the small diameter wire), should be twice as large as the distance between the ground probe and the spark probe, (the wire that looks like a spark plug wire). You do not want the spark jumping to the flame sense probe. This could damage the printed circuit board. Also be sure a new gasket is used whenever replacing the electrode assembly. Air leaking into the combustion chamber will indeed cause a disruption in the fuel/air ratio and lead to improper and incomplete combustion. Be sure to reinstall the assembly in the exact position as equipped from the factory. Finally, be sure there is no obstruction in either the exhaust vent assembly or the fresh air intake assembly at the exterior of the RV. Over time, critters such as mud-daubers and wasps love to build nests in those tubes. All of the above tasks, collectively called a "clean & service," are an important maintenance requirement each year for all LP burning appliances. Performed annually, it will minimize and most likely eliminate such problems. If you are a handyman around the RV you might want to attempt this procedure yourself. We have an instructional video presentation for the furnace clean and service that is now available to everyone. This tape was written and produced for the professional RV technician and is used in RV training schools everywhere. If you are interested in obtaining one, send us your mailing address and an order form will be sent to you. In any case, yearly maintenance is a must. Dear RV Doc, do know of any special way I can track down a water leak in my roof? My right wall (inside), near a window gets saturated when it rains. I have completely sealed off the roof and the window. The trailer remains parked all the time. Reyes Rivera, (Baldwin Park, CA) Reyes, water seeks its own level, so any moisture manifesting near one wall or any window can actually enter the RV at any point above that. In other words, rain water can enter through a cracked seal around anything screwed to the roof or side walls and drip downwards until you actually see it under that window. The best advice is to carefully and completely inspect the roof area of the RV. Look closely for dried and cracked sealants around vents, pods, antennas, roof racks, ladders, etc. Anything screwed or bolted to the roof is a possible entry point. If your rig is equipped with a front and rear cap, check closely the overlapped portion. If you have a rubber roof, look carefully for scrapes, tears or small holes anywhere. You may be able to isolate the leak to a certain area by using a garden hose to saturate one portion of the rig at a time. Be sure to use a lot of water and let the unit stand for awhile to see if any new water appears at that same point. Check the sealant around all the windows and the entry door as well as the trim molding on the sides and rear of the coach. Running lamps can also be a place where water enters the void between inside and outside walls. Basically you must carefully check anything mounted above that window all around the RV. Perseverance will pay off. Take your time. Dear Gary, if you were buying a used 1999 motorhome from a dealer, what would you have them check and repair before you took delivery? We are brand new to this, and have never owned or used an RV before. Myra Echols, (Cumming, GA) Myra, purchasing a used RV for the first time can indeed be quite daunting. Unfortunately there are a few unscrupulous peddlers out there, but by and large, most are reputable dealerships. Prior to buying any used RV, I would first check with the Better Business Bureau to see if that company has any complaints on file. It is usually best to buy from a long-standing, established dealer with a track record in the community. This isn't always a guarantee, but it is certainly better than buying from the guy who just rented that vacant gas station parking lot and hung a cardboard sign in the window. Be sure to check the Blue Book prices first so you will have some idea what the retail value would be. All reputable dealers perform what's called a Pre-Delivery Inspection (PDI) on all the coaches they sell. For one thing, they must be certain the RV passes industry mandated and/or state requirements for safety concerning the LP system, the plumbing system and the electrical systems. Most PDI's are quite lengthy and involve testing literally everything on the unit. This takes four to five hours to complete for the typical motorhome. Every item should be in good working condition. Ask your dealer to see the technician's sign-off PDI sheet for that RV. You must satisfy yourself fully that an honest and factual PDI was performed whether he allows you to view the sign-off sheet or not. I'd question why if he refuses. Additionally, ask direct questions about the warranty. How long is it? Does it cover absolutely everything? Most in the industry distinguish a difference between the chassis and the RV section. Be sure you understand exactly what is covered under their warranty and what is not covered. Important to ask; "What is the procedure should I experience the unlikely event of a breakdown while on the road?" Will you pay for the emergency repairs I must have performed while out of town? What is the exact procedure? This is assuming there is a warranty. Of course, the dealer can sell the unit, "As is" meaning there is no warranty at all and you get just what you see. Only experienced RVers should ever consider buying an "As is" used unit. It typically means there is something wrong (read; expensive to fix), with the RV. A reputable dealer will allow you to take the unit to your mechanic for an inspection prior to closing the sale. You will have to pay for this service, but you will be getting the satisfaction of knowing your guy checked it out. This is considered cheap insurance and money well spent. Better to spend a few bucks up front rather than wallow in a poor decision that in all likelihood will cost much more later on. Any item that needs repair now becomes a bargaining chip during the price negotiation. Consider asking an experienced RVing friend for input. Finally, go on your gut instinct. You've bought other things before. What is your gut level feeling about this purchase? Has there been any coercion or pressure to buy this unit right away? It is best to make large purchasing decisions only after doing your homework and sleeping on it a few days. If it's been sold by the time you return, then that coach wasn't meant for you. Keep in mind there are literally hundreds of thousands of used RVs available. This could be the coach of your dreams......or it could not. Make an informed decision based on the facts at hand, not simply on the lure of the lifestyle and blue sky.
|
|
|
[ Home ] [ Ask the RV Doctor ] [ RV Doctor Column ] [ Memorandums ] [ Interesting Articles ] [ Product Spotlight ] [RV Service Technician Training ] [ Seminars ] [ Links ] [ Gary's Bio ]
Send your questions and comments to:
gbunzer@cox.net |
|