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Most people have a hot water heater in the house. Anyone know how to change a John Woods heater's Anode rod? Answered

Its a plumbing problem possibly requiring cutting copper pipe and soldering fittings together. Basically I need to know if the anode rod is in the same place as usual for most hot water heaters or if my John Woods hot water tank does have the anode connected to the hot water intake. If so, how am I going to save money and change the magnesium anode rod myself rather than paying a plumber 80$/hour.


If the anode rod on your water is like mine, then you can get it loose just by putting a wrench on it and unscrewing it, at the hole where it fits at the top of the water heater.

However the process may be complicated by the fact that the new anode rod is long, and it will likely hit against the ceiling before you have pulled it all the way out. 

One way to get the rod into place is to tip the whole water heater at an angle, so the top moves away from the ceiling, but you probably do not want to do that because the water heater is big and heavy, and also physically connected to water pipes and other things.

If you could cut a hole in the ceiling right above where the rod goes, that might be handy.

Or perhaps they make anode rod that comes in short sections that can be threaded together?  So you could sort of assemble, a section at a time, lowering the end into the hole as you did this. I have never seen an anode rod of this kind, but it would be handy if such a rod existed.

The only anode rod I have actually seen, was one that came with a new water heater that I installed recently.  This rod was about 4 feet long, and I had to tip the water heater at an angle, to get enough space between the top of the tank and the ceiling in my basement, to get the anode rod back into the tank.

You might wonder why I went to the trouble of taking the anode rod out of a new water heater, but I assure there was a good reason for doing this.

How do you know it needs replacing, out of interest ?

most water tanks around here seem to get 10ish years without an anode rod replacement. That means the rod corrodes first and then the tank within 10. The tank I have is 5 years old. i bet it needs doing. Its a 30$ part and the plumber I had over to give me a quote told me that the rod was connected to the hot water intake just to make it harder for DIY-ers. The only way to know for sure if it needs doing is to take out the old one. If im going to do that much, I might as well put in a new one.

I assume yours are made of steel ? In the UK, we've used copper tanks since forever. Mine's coming up to 25 years old, my mom's is over 40 ! With copper pipes as well, they LAST !


They sell a few models, and without knowing yours, I'll have to assume that from one model to another there isn't any major design differences (except size) with John Wood. According to this pdf I found, they say the Anode rod is top mounted. The pdf includes a diagram if that helps.

Here's some good information about anode rods, DIY inspection and replacement. Obviously, the condition of your water (and a few other factors) will determine how quickly the rods will dissolve, but (at least in North America), its suggested that the rods should be checked every 4-5 years. Unfortunately, most people aren't even aware that they can and should inspect the rods and replace them when needed to extend the life of the tank. So kudos' to you for knowing that. ;)


6 years ago

The anode rod is there to prolong the life of the tank. It is "sacrificial" in that it is designed to be attacked and eventually dissolved rather than the tank itself. Most of the time they will outlast the life of the heater. Because of this they are seldom thought of as needing replacing. Usually when the rod is gone the heater has come to the end of its life. It will depend on your water though. Where I live the water is very alkaline and has a lot of iron in it. The magnesium rods in the heaters combine with the water and turn it black and sulfurey rotten egg smelling. A lot of people have taken the rods out when they first install the heaters. The rods are usually screwed into the tank very much like any water supply pipe. To remove them you unscrew the cap and pull the entire rod out, then with a hack saw you cut it off from the plug and then screw the plug back in. If you file down the rod and get a little pile of filings you can light it with a torch. Its magnesium and it burns super bright.
Anyway, some water heaters here are more than 30 years old without having the rods in them and are still water tight. I would suggest that you just leave yours alone and save up to replace it when it finally starts leaking.