The Tank › New water heaters
- February 1, 2005 at 10:11 pm #3230Guest
Hello: I am installing four new water heaters in my rental units. I am trying to set them up for future mentainance according to the ideas set out on this site. These are all Kenmore Rotoswirl 9 year models – two 30 gal standard height models and two 40 gal short models. I unscrewed the anode rods from all of them and noticed the following: the two 40 gal and one 30 gal models had 24inch rods. The remaining 30 gal model had a 40 inch anode which looked more shiny than the others. I assume that they all were aluminium anodes as they had hex heads. They were all about 3/4 inch in diameter.
My question is: why does one 30 gal tank have a 40inch rod and the other 30 gal tank have a 24 inch rod? They are identical models. All things being equal, would the longer anode with more meat give better protection to the tank it’s installed in? Do you think this is a factory oversight, or something more sinister like an attempt to shortchange the buyer? By the way, all the tanks have 24inch combo rods in the hotwater outlet.
More questions: Both the anodes and the TP valves were screwed in with a white joint compound which I assume was some kind of teflon formula. Is wrapping the threads with teflon tape a superior way with respect to removing them years later when heat and corrosion have done their work?
I have seen a previous post where the difficulty of removing the anodes even on new tanks was discussed. I got around the problem by removing the TP valve and screwing a 24 by 3/4 inch nipple in its place. This gave me enough leverage to use a 24 inch breaker bar with a 1 3/4 socket on the anode rod head. With the two opposing forces it was easy to work with the tank in an upright position and keep it from waltzing all over the boiler room floor. It will be interesting to see how this works out a few years down the road when the tank is full of hot water and the parts have fused. I don’t know how hefty the metal tank is, but I hope I haven’t twisted anything by using the method I described and applying force to the side of the tank. Would the slightest flex of the TP valve tapping on the side wall cause the glass lining on the tank interior to crack?
Thanks for any response from the experts….. ArnieFebruary 2, 2005 at 1:20 pm #3231Randy SchuylerKeymaster
I enjoyed your post. You touched on several interesting issues. As to the anodes, the only reason the hex anodes might be that short would be if the tank was too short to accommodate longer ones.
Half-length combo rods, however, are not unusual. Many tanks with longer warranties have one full length hex rod and a half-length combo rod. If the tanks will accommodate longer anodes, you should put them in, since the more anode metal in the tank, the longer the tank will last.
If the hex heads had a bump on them, as in a comparison photo I have on the product page of my site, then they’re magnesium. If the hex heads are flat, the rods are aluminum. Whatever metal the hex anodes are made of, the combo rods will be the same.
What you used to remove the anodes is a technique we recommend, except that you can just use the hot and cold nipples instead of putting a nipple in the T&P port. That should spare you some trouble in later years when you go back to check the anode.
Essentially, you take one pipe wrench with a long handle and place it on the nipple the farthest from the anode turning in the closing position, with the handle extending past and touching the other nipple. Then you put another wrench on the anode and squeeze the two handles together, as you describe. I’ve started including a diagram with anode orders describing this and another technique, since some people have experienced difficulty removing anodes.
I don’t think you damaged the glass lining with the action you described.
As to the pipe dope, it could be anything. I know some plumbers like Teflon dope, but we prefer the tape.
Randy SchuylerFebruary 3, 2005 at 1:21 am #3241Larry WeingartenParticipant
Hello: Might I suggest you use the method Randy describes for loosening tight fittings? Screwing a pipe into the T&P port, I feel could easily cause damage. Tanks are not made of particularly heavy steel. I’ve seen tanks flex just by wrenching on a side mounted T&P. The two foot pipe trick makes me nervous! But, the anode will protect any new holidays. 😉
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