House Calls with the RV Doctor
By Gary Bunzer
February 2007
Dear RV Doctor:
The head of the nylon drain plug on my water heater broke off while removing it to drain my Atwood water heater. Is there a trick to removing the remainder of the plug without damaging the threads? Hopefully, I’m not the first person to ever experience this. Any ideas?
Les Williams
White House, Tennessee
RV Doctor: I have seen this problem before, Les, so you’re not the only one. And it’s basically caused by someone tightening that plastic plug a little too tight and possibly using an incorrect sealant on the threads. Over time, exposure to the heated water has caused it to be nigh impossible to remove easily. Another factor is that exposure to UV radiation degrades all plastics, making them brittle and more prone to breakage.
If the head is totally broken off, you’ll have to drill a hole through the center of the plug and use a tool commonly called an “easy-out” to remove the plug (see photo). Also called a screw extractor, easy-outs are available at any hardware store and come in various diameters. You’ll want one about half the diameter of the plug; the larger the easy-out, the less force is required to back the broken plug out. The flutes on the easy-out are “left hand,” in that when tapped into the hole in the plug, they will grip and embed themselves into the edges of the drilled hole. You can then use an adjustable wrench or socket to remove the plug. After removing the remnant of the plug, turning the easy-out in the opposite direction while holding the plug will cause it to release its grasp. Using an easy-out also will keep you clear of the soft aluminum female threads on the inner tank of the water heater.
Clean any leftover sealant from the drain opening threads with a stiff brush and install a new brass plug. Be sure to use a fresh-water-approved sealant on the male threads of the new plug . . . and don’t overtighten!
Cranky Convertor
Dear RV Doctor:
My parents recently purchased a used 1997 motorhome that has a Magnetek convertor with a battery charger. All of the circuits on the convertor are working okay. On the charger side, the output stopped the first time they plugged it in at the campground. From what I gather, Mom was listening to the radio while packing the RV before they left. When they got to the campground, the radio would not work. The battery is new. The transformer is putting out more than 16 volts on one side and only 8 volts on the other. I don’t want to waste anybody’s time if this is a lost cause. Where can I find some technical info or a replacement unit?
Rob Gibson
Findlay, Ohio
RV Doctor: Rob, some older convertor-chargers are quite capable of being repaired as long as parts are still available for them. However, in some instances of undersized convertor outputs (for the application), or convertors of lesser quality (components or design), it may be best to upgrade to one of the newer, sophisticated, multistep chargers. Some of the current designs employ actual computers with special algorithm principles that can truly satisfy today’s high demand for onboard 12-volt power by keeping the battery bank fully charged, without the fear of overcharging. Sadly, many of the earlier convertor-chargers used in the RV industry were mediocre at best. Some were underpowered, while others were prone to literally boil the electrolyte out of the batteries. Before condemning any convertor, however, I recommend a complete bench test and an internal electrical “checkup,” if you will.
Like I’ve mentioned before, some convertors can be repaired quite successfully, so you must be prepared to choose between a repair and a new convertor. Here are some factors to consider: How long do you think your parents plan to keep that RV? Are they thinking about a trade anytime soon? Do they want the absolute best of today’s technology? Answers to these questions will help decide between a repair of the existing convertor or a new one. But before you can even consider such a choice, you must first have the existing convertor analyzed by performing very specific tests and measurements. Unfortunately, without actually viewing the convertor first-hand and performing these diagnostics, I’d just be guessing.
I do, however, have a recommendation for you. When it comes to convertor-charger experts in the RV industry, I recommend Master Techs. They are located in Marshall, Michigan, but they receive convertors from all over North America for repair. They have a quick turnaround time (they ship back to you within 24 to 48 hours) because of the considerable inventory of spare parts they carry for virtually all brands of convertors. Chances are they will have the convertor tested, repaired, and shipped back to you faster than you could secure an appointment at a local RV service facility. Chances are also that facility would have to order the repair parts from Master Techs anyway; that is, if they even do internal convertor repairs at all. Not many shops dig into the innards of a charging convertor. To have your convertor checked out by Master Techs, call (800) 848-0558. They will provide all the necessary information to ship your convertor to them.
Battery Capacity
Dear RV Doctor:
One of my Group 24 series batteries has gone bad. I would like to replace them with 6-volt golf cart batteries. I was at the Pennsylvania RV and Camping Show and attended your battery seminar. I thought you told us we would only need two 6-volt deep-cycle batteries. Can I do this? How many do I need and how do I hook them up? I have a Holiday Rambler Presidential 36-foot coach. Everyone I ask tells me I’ll need four 6-volt batteries to replace the current 12-volt batteries.
Richard Baker
New Enterprise, Pennsylvania
RV Doctor: Richard, your two Group 24 batteries connected in parallel yield approximately 170 combined amps of storage (about 65 amps each). Two Trojan 6-volt batteries wired in series yield about 225 amps at 12 volts. The more batteries you add, obviously, the more current you’ll be able to store. Four of the same 6-volt batteries wired in a series-parallel configuration, for example, will provide about 450 amp-hours of use. Even if you had two Group 27 batteries in parallel, they would total about 210 amps, still less than two 6-volt golf cart batteries.
When one is wiring two 6-volt batteries in series, the hot lead (from the RV) connects to the positive post of one battery and the negative lead to the negative post of the second battery. A jumper cable interconnects the two batteries between the negative post of the first battery and the positive post of the second battery. Connect the positive cable to the first battery first, then the interconnecting cable second, and, finally, the ground cable to the second battery as the last step.