Home & Garden

Maintenance of Hot water Tank -- Anode replacement

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  • Oct 15th, 2015 7:55 pm
Sr. Member
Nov 24, 2002
900 posts
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Toronto
Just wanted to add my experience to this thread, in case anyone bumps into it in the future.

- Water heater installed by previous owner with Direct Energy June 2004 - 50 gallon direct vent
- I purchased the water heater from DE Jan 2013 for ~500$
- Today, I decided to replace the anode rod inside of it (original to the water heater) to extend my investment in the unit (funny how rental companies never replace this consumable component of the water heater .. almost like they want it to fail early, so they can lock you in into an even more expensive unit down the road..)

I purchased the anode rod from Home hardware for 22$ + tax. 1 1/16" socket from Canadian Tire (~8$) - these only come in 1/2" socket wrench. Most home owners / kits use 3/8" so be aware!

First attempt: Use 14" long breaker bar. No go. No matter how much I tried, 8 years of buildup in the tank (and the fact that these bolts are connected to the tank via impact wrench in the factory) made sure that I would never be able to open it. In addition, the long breaker bar was actually moving the tank! So be careful if this is what you attempt to do.

Second attempt: Borrow friend's 1/2" 8 amp (350lb/ft) wired electric impact wrench. It had the old anode off in about 3 seconds!

Condition of original anode: Surprisingly ~75% was still there! BUT Downtown Toronto water has very high calcium content (any home owner with humidifier knows this well) There was ~2mm crust around the entire anode.

I wrapped teflon tape around the bolt, inserted it into the hole, and used the electric impact wrench to tighten it back down (having this thing is a life saver, as it allows you to easily work in tight spots and doesn't twist / move the water heater!!) Turned the water back on, and made sure there were no leaks. I also confirmed with a volt meter that there's perfect continuity between the bolt of the anode and one of the copper pipes going into the tank. This confirmed that the entire tank was well connected to the anode, and that it could do its job!

Entire process beginning to end (if you have all your tools and components lined up): 15 minutes.

Good luck all with extending the life of your water heater!
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Aug 27, 2009
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leonk wrote: First attempt: Use 14" long breaker bar. No go. No matter how much I tried, 8 years of buildup in the tank (and the fact that these bolts are connected to the tank via impact wrench in the factory) made sure that I would never be able to open it. In addition, the long breaker bar was actually moving the tank! So be careful if this is what you attempt to do.

Second attempt: Borrow friend's 1/2" 8 amp (350lb/ft) wired electric impact wrench. It had the old anode off in about 3 seconds!
I had the same "first attempt" experience except my water heater was only 1 year old and I used a 20" cheater bar, but was unsuccessful so I gave up.

Given that the tank is "glass lined" I hesitated to use an impact wrench. Are you sure the anode is installed in the factory using an impact wrench? If it is maybe I'll give the impact wrench a go.
Sr. Member
Nov 24, 2002
900 posts
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Toronto
I've done a lot of research online about this, and it seems that a majority of pros use impact wrench. In fact, they say that impact wrench is less damaging to the tank than cheaper bar. Which makes a lot of sense if you ever see how an impact wrench works.. It's very similar to hammer drill, high RPM, very very short bursts. The nut turns really slowly.
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Feb 10, 2011
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I worked at GSW for 5 years building water heaters. they use a white pipe dope applied by brush then the use a air impact gun to tighten it. The longer the anode the longer the warranty. I know in some towns with a certain kind of water they would have to remove the anode.
No One Goes to Palmerston Ontario
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Jan 8, 2013
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OSHAWA
BinaryJay wrote: I would say almost never? The point of a pilot is to keep a draft going and power vents make their own draft with a damn noisy fan. I want to mod my powervent with some Noctua fans, I hate when the thing kicks in even though it's in a finished enclosed space.
The point of a CONTINUOUS Pilot is to generate electricity to either prove that the pilot is lit (thermocouple 120v design) and pull in the pilot stat so the main gas valve can open, or to generate electricity to operate the gas valve (thermopyle milivolt design, no external power). The point of the pilot on an electronic ignition pilot powervented water heater is to light the main burner off of an already ignited gas source. Many power vent water heaters have pilots but are of the electronic ignition variety meaning the user doesn't need to light it themselves.
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Oct 19, 2007
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Redfisher wrote: I worked at GSW for 5 years building water heaters. they use a white pipe dope applied by brush then the use a air impact gun to tighten it. The longer the anode the longer the warranty. I know in some towns with a certain kind of water they would have to remove the anode.
I just bought and installed a John Wood water heater and it looks very similar to GSW (I wonder if they're the same company). If so what kind of anodes are they using - ie magnesium or aluminum? I plan on buying a kit (anode + flush kit) from Waterheaterrescue.com

How is GSW build quality compared with Rheem / GE for example? Also between GSW tanks with different warranties, was there any other difference in build quality (aside from anode length) - ie glass lining thickness, steel grade, inner parts, etc?


Thanks in advance
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Feb 10, 2011
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wally_walrus wrote: I just bought and installed a John Wood water heater and it looks very similar to GSW (I wonder if they're the same company). If so what kind of anodes are they using - ie magnesium or aluminum? I plan on buying a kit (anode + flush kit) from Waterheaterrescue.com

How is GSW build quality compared with Rheem / GE for example? Also between GSW tanks with different warranties, was there any other difference in build quality (aside from anode length) - ie glass lining thickness, steel grade, inner parts, etc?



Thanks in advance
Yes the john Wood is made by GSW.
They use Magnesium anodes.
I feel GSW are one of the best makers of water heaters.
only difference is the anode length, I use to apply the glass lining and it was the same for all tanks.
No One Goes to Palmerston Ontario
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Aug 27, 2009
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Redfisher wrote: The longer the anode the longer the warranty.
Longer warranties usually come with the more expensive water heaters. Are there any other differences besides the (longer) anode rods in the good/better/best WHs? More insulation perhaps? Sometimes the more expensive ones also come with larger burners.
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Feb 10, 2011
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RETD wrote: Longer warranties usually come with the more expensive water heaters. Are there any other differences besides the (longer) anode rods in the good/better/best WHs? More insulation perhaps? Sometimes the more expensive ones also come with larger burners.
Sure some things will be different with the more costly models, I know for a fact with the same model tanks the only difference between the 5 year and 7 year warranty was the length of the anode.
No One Goes to Palmerston Ontario
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Oct 19, 2007
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wally_walrus wrote: I just bought and installed a John Wood water heater and it looks very similar to GSW (I wonder if they're the same company). If so what kind of anodes are they using - ie magnesium or aluminum? I plan on buying a kit (anode + flush kit) from Waterheaterrescue.com

How is GSW build quality compared with Rheem / GE for example? Also between GSW tanks with different warranties, was there any other difference in build quality (aside from anode length) - ie glass lining thickness, steel grade, inner parts, etc?


Thanks in advance
Redfisher wrote: Yes the john Wood is made by GSW.
They use Magnesium anodes.
I feel GSW are one of the best makers of water heaters.
only difference is the anode length, I use to apply the glass lining and it was the same for all tanks.
Thank you! Much appreciated!
Sr. Member
Nov 24, 2002
900 posts
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Toronto
There's an easy way to find out what anode you got. Look at the top of it (without removing it). If you see what looks like a disc in the middle of the bolt, you got magenisium, if it's a single metal then you got aluminum.

No matter what you got, be aware that tank manufacturers don't make anodes. They're as standard as furnace air filters. Buy it at local plumbing supply store and cut to size. I got my GSW anode at home hardware for 22$
Jr. Member
Jan 12, 2006
122 posts
33 upvotes
Toronto
Thanks for a timely and informative post. Picked up a new magnesium rod from Home Hardware for $22.99 and installed. The old aluminum rod wasn't very badly corroded and looked to be full length but still preventative maintenance never hurts and it was nearly 4 years old. Tried a few methods to get the old one out - just a 1/2" ratchet, long breaker bar, air impact gun (smaller compressor - not enough torque) and finally the electric impact from CT (7.5A 1/2" on sale now for ~$50) which did the trick. The breaker bar moves the tank way too much and unless you have someone strong to help or can brace the tank properly I would not recommend. Electric impact gun had the old anode rod out in a few seconds. It was a bit of a tight squeeze and I had to disconnect and move part of the exhaust as that gun is quite large. Didn't use the vinegar as suggested but did drain a bucket or more of water from the bottom of the tank - there was no rust/residue that I could see. Used teflon tape on the new rod to ensure a proper seal but didn't cover more than half the threads and tested with multimeter after to ensure continuity. My 40 gallon GE tank has a 9 year warranty but to me this is a very easy and cheap measure to ensure it lasts at least that long.
Deal Addict
Jan 11, 2007
1275 posts
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Brampton
Thanks to the op and others in this thread I finally got around to doing this. Tank is over 13 years old and like a poster earlier on, I had a good 2 mm of calcium build up but a lot of the rod left. It looked like the calcium was possibly impeding the function of the rod as it was only corroded in a couple areas.

The tip to use the impact gun was a good one and it made it an easy 10 minute job. I picked up the magnesium rod at Lowes for about $20 and they had a couple other types available there as well.
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Nov 18, 2005
11955 posts
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Kingston
stevezed wrote: I really wanted to replace mine, but I think it must be seized up. I went to town on it with an adjustable wrench and couldn't get it to budge.
I had this problem with a brand new GE tank. Actually had the tank replaced under warranty only a few months after install because the anode couldn't be removed.
-jinx- wrote: Thanks for a timely and informative post. Picked up a new magnesium rod from Home Hardware for $22.99 and installed. The old aluminum rod wasn't very badly corroded and looked to be full length but still preventative maintenance never hurts and it was nearly 4 years old.
everylittlecent wrote: I would think the water is of similar quality and would change it every 3 odd yrs. How old is your tank. after all if youre doing it the part is less than $20 :D
The maintenance instructions for my tank say to check it every year, but only replace it when the anode is corroded down to the wire (in any spot). As long as you have material left on the anode there is no benefit to replacing it (other than you could forget about checking it for a longer period of time)
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Aug 27, 2009
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I recently got around to checking my anode last weekend. WH is 2 years old, gas-fired, 50 US Gal GE Model from Home Depot. Our water comes from Lake Ontario.

An impact wrench made removal very easy.

The rod also had about 2mm of crud on it after only 2 yrs while others had the same after many more years. It was more corroded at the top and bottom and at random spots along the length. Cleaned off all the crud, teflon taped the threads and re-installed, checked continuity. Given the amount of crud I'll probably service the anode annually.

When I drained some water from the bottom of the tank I was struck by how non-hot the water was. When measured at the tap the temp. was about 55C (130F) but the water from the bottom of the tank, while hot, was not too hot to the touch. That explains why sometimes we sort of run out of hot water even though there's no way we've used 50 US gal of hot water.

Obviously there is a temp. gradient in there but if the water at the bottom is not at such a high temp. it's probably not hot enough to kill all the bacteria.
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Jul 20, 2012
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RETD wrote: I recently got around to checking my anode last weekend. WH is 2 years old, gas-fired, 50 US Gal GE Model from Home Depot. Our water comes from Lake Ontario.

An impact wrench made removal very easy.

The rod also had about 2mm of crud on it after only 2 yrs while others had the same after many more years. It was more corroded at the top and bottom and at random spots along the length. Cleaned off all the crud, teflon taped the threads and re-installed, checked continuity. Given the amount of crud I'll probably service the anode annually.

When I drained some water from the bottom of the tank I was struck by how non-hot the water was. When measured at the tap the temp. was about 55C (130F) but the water from the bottom of the tank, while hot, was not too hot to the touch. That explains why sometimes we sort of run out of hot water even though there's no way we've used 50 US gal of hot water.

Obviously there is a temp. gradient in there but if the water at the bottom is not at such a high temp. it's probably not hot enough to kill all the bacteria.
There is a reason why the water is cooler at the bottom of the tank. There is a dip tube at the cold inlet that forces the incoming water to the bottom of the tank.
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Brian71 wrote: There is a reason why the water is cooler at the bottom of the tank. There is a dip tube at the cold inlet that forces the incoming water to the bottom of the tank.
I realize that, but the WH hadn't been used for a while (no hot water drawn) and the burners weren't firing so the controls thought the water was at target temperature. I would have thought that most/all the water in the tank would be "hot" but apparently not, as least not with my WH.
Deal Guru
Nov 19, 2010
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Lol my tank has warranty for the next 20 years. No worries.
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Oct 4, 2001
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Thanks op. I just took the old anode out and LOW BEHOLD there is no ANODE. The water heater is a RHEEM about 6 years old. Someone told me that the anode was good for 10 years so I was not worried. I quickly ran to Home Hardware and replaced it. Should I be worried that perhaps the water heater is now rusted?
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Jun 22, 2012
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wilsonlam97 wrote: Lol my tank has warranty for the next 20 years. No worries.
It's probably limited in some way that will give you worries if you need to claim it.

But more importantly, if a hot water tank leaks and causes $40,000 damage, will it really matter that the tank company gives you a replacement of their $700 device? If $25 and 10 minutes of effort could prevent that, wouldn't that be something you'd consider?

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