Q. I have a water heater in my RV. Every year I drain it for storage. When I do, I notice that the anode rod, which is also the drain plug has been at different stages of decay.

Mark Says: It's a good thing you drain the water heater and that you take notice of the anode rod. Many people don't know it's even there. Anode rods are used in suburban water heaters because they have steel tanks. The anode rod attracts minerals and deposits that could be harmful to the tanks lining. These deposits eat away at the rod rather than damaging the tank. I would replace the rod when it's about 75% consumed.

Q. Would like your thoughts on pros & cons of towing a trailer behind my F/Wheel because I miss my Harley-Davidson during long winter stays down south! Also do you know of states laws prohibiting this? Thanks in advance for your reply.

Mark Says: It's quite common for people to tow things like boats and small trailers behind their trailer. Some concerns are the hitch on the back of the trailer, it needs to be capable of supporting the additional weight and the tow vehicle you are towing with needs to have a tow rating capable of towing the total amount of weight. If you were to exceed the vehicles Gross Combined Weight Rating your insurance or vehicle warranty may be voided in the event of an accident or breakdown.

As far as the legal issue goes, here is a link that shows each states laws for trailer towing. You will notice that one of the criteria is for towing two trailers. The one thing I'm not sure of is, if it's legal to tow two trailers in the state you live in can you tow that configuration across the border of another state and still be legal. You may want to contact the highway patrol and ask that question.

Q. Where would I be able to get instructions on using the convention/microwave oven in our motor home. It was put in to replace the original one but the instructions were lost prior to our purchasing the used motor home. So far the oven has not been used at all other than to heat something up.

Mark Says: Try to identify the manufacturer of the convection oven and go to their web site. Often times they will have the owners manuals available for download.

Q. I have a 27 foot Dutchman Travel Trailer that I bought new in 2002. To date I have blown out 7 tires. I am now on Goodyear radials having replaced the O.E. Carlyle tires. My question is this: Do tires on a trailer require balancing and alignment like a car? I just find it amazing that I have had that many blowouts.

Mark Says: My first thought would be that the tires are overloaded. If you haven't done it yet take the trailer to a set of scales where you can weigh each wheel position separately. Compare the weights to the tire weight rating when they are inflated properly.

I have heard a lot of people complain about Carlyle tires, but seven blowouts indicates some other type of problem. Balancing the tires cannot hurt but isn't absolutely necessary. Alignment for a trailer is usually related to one of the axles shifting over. If you stand in front of, and then behind the trailer look to see if both axles (tires)are aligned with each other. If one of the tires sticks out further than the other take it in to have it checked out.

I still don't think this is what is causing the problem. Weigh the wheel positions and try distributing any weight in the trailer so none of the tires are overloaded. Another important factor is to make sure you are using replacement tires designed specifically for trailers. The sidewalls are designed to hold up to the twisting and flexing that occurs when you make turns etc.

Q. I just subscribed to your newsletter, hoping for some helpful info as I get re-involved with motor homing. I sold my 24' class C and am shopping for something newer and more efficient, also larger. I'm tending toward the Class B+ Phoenix Cruiser, 27' with 2 slides. It comes as either gasoline or diesel. I've been told the additional cost for a diesel engine outweighs any gas mileage benefit unless you keep the rig for many years. But I also wonder if other things have been factored in, such as, cost of engine maintenance, cost differential for the fuel type (as gasoline prices rise, will diesel rise at the same rate, slower, faster? What about bio diesel? Is there a re-sale advantage to either one?

I haven't found a discussion of these issues anywhere yet. The dealer I've been working with just gave me the answer above... not cost-effective unless kept for many years.

I'm an older, single woman, wanting to do some touring with my dog for the next 2 years or so. I'm expecting various friends to link up for certain legs of the trip. I will appreciate good guidance.

Mark Says: Gas versus diesel is an age old discussion and one that often times gets heated. If asked this question several years ago I would have responded similar to the salesperson, because the cost difference was quite significant. Tody's RV's offer many gasoline models in the same price range as many diesel products. Mainly due to advances in the chassis itself driving the prices upward.

What I can tell you is a diesel will last longer that a gasoline engine so if you plan to keep the RV for a good amount of time it would be worth the investment. I have no idea what is going to happen with the types of fuel or the cost comparison between gas and diesel.

Maintenance wise it used to be that a diesel required less, keeping in mind there are more filters etc. on a diesel, but nowadays gas engines can go upwards of 100,000 before a tune up, with nothing more than routine oil changes, air filters etc.

This probably doesn't help much. If you want some other peoples opinions I recommend you go to the open roads forum and post this same question in the appropriate forum. You are sure to get many responses.

Q. I'm writing to ask which of your DVDs you think would be the most helpful for someone needing help understanding rv electrical systems and learning how to tap into them for simple projects such as a fridge baffle compartment fan, adding a 12v plug receptacle to charge things like cell phone, etc.

If not one of your DVDs, if y'all know of a book I'd really appreciate the advice. Thanks.

Mark Says: I don't think any of our DVD's would be helpful in these areas. There are a couple of books that might be useful to you. The RV Handbook and RV Repair & Maintenance.

Q. We have a 2003 23 ft. Komfort trailer with one airconditioner, micro wave, radio, and TV. Would you please tell us how to determine what size generator we need for the trailer?

Mark Says: The easiest way to determine what size generator you need is to calculate how many watts you plan to use at any given time. I am including 2 links that will tell you how many watts everything uses and then there is a link where you can plug those figures in and it will tell you the size generator you will want to get.

Q. I Have a Refrigerator that's freezing up. It Happened after we defrosted it last august. as of may 1 after turning it back on, it still freezes. any help?

Mark Says: Here is one possibility. Look inside the refrigerator compartment toward the back and you will see some fins. On one of those fins there will likely be a small piece of plastic. You can slide it up or down on the fin. That will control the temperature inside the refrigerator compartment. If it gets bumped or moved from it's original position it can cause it to freeze in the refrigerator. The problem is I don't remember which way to slide it to make it stop freezing. Get a small refrigerator thermometer and experiment with it to see where it needs to be adjusted. It will take quite a bit of time in each position so be patient. You want the temperature in the refrigerator to be around 36 to 37 degrees. Food can begin to spoil at 40 degrees.

Hopefully this will correct the problem.