Anode length and drain size American Standard water heater

[BurtEggley]

Have American Standard 2021 water heater installed early January 2022. Model GN50T1-3-6. (it is GN and not GSN) Low NOX 50 gallon residential. No where can I find an actual parts list for this unit after hours of searching. At 4 years it is time to check the Anode rod and flush it. The flush drain opening is small and we wanted to upgrade it to a large size opening on the drain valve. Most water heater drain valves are 3/4 in size but this one is stamped 21/31 and has AS (American Standard?) on the other side. What the heck size is a 21/31 plumbing size/thread? 3/4 would be same as 21/28 so my concern is a 3/4 might be loose, although MNPT is tapered.

As to the anode rode, the manual says they all ship with aluminum anode rods but there is no length. I don't want to buy a longer one and cut it, or have to pull it out once to measure, see if I already have one or go shopping if I don't. Anyone know the length of the anode rod on a 50 gallon natural gas American Standard water heater?

Happy New Year to all.

 

[nafterclifen]

I thought to myself, there HAS to be a parts list. But you weren't kidding - I couldn't find one either. I did find some info that might help though.

In the Instruction/Install Manual on this page, https://www.pacesupply.com/Product/ASWNLN50NT, it says...

In each water heater there is installed at least one anode rod (see Parts section) for protection of the
tank. Certain water conditions will cause a reaction between this rod and the water. This is defined
as smelly water and removal of the rod will void any warranties stated or implied. The parts list includes
a special anode that can be ordered if odor and/or discoloration of water occurs. However, this rod
is only good to a certain point, after which, we can only suggest that a water conditioning company
be contacted to supply filtration equipment.

That sort of tells me the manufacturer doesn't want you messing with the original aluminum anode rod. But get this - they off a warranty upgrade kit to increase warranty from 6 to 12 years. And guess what's in the kit? A 2nd (magnesium) anode rod. Part number for that kit is 50315160005. More info and pics on this page, https://www.gosource.us/products/pace_supply_p_50315160005

You can try entering your serial number on this page, https://www.americanwaterheater.com/service-support/replacement-parts, and see what it shows you for replacement parts.

 

[BurtEggley]

I think that American Water Heater, and American Standard are different companies. Thank you though for trying. The owners manuals have a back page that says parts. It shows all the parts but no part numbers. I guess I will just try a 3/4" brass setup, and see if it fits. As for the anode rod, the sales spec sheet for my model does say aluminum rod. However all the other models say magnesium rods, so I don't know how reliable the sales spec sheet actually is. I guess I could just pull it and grind on it to see what color the sparks are. Don't want to accidentally ignite magnesium because the idea of a 3' long magnesium flare doesn't excite me - although it might excite some people. They used to burn magnesium VW cases out in the desert back when I was a young man. Throw a bucket of water on it and watch it take off as the magnesium strips the oxygen from the water - same if CO2 is used to try to put it out.

 

[rlitman]

Once you go anode rod shopping, you'll find that the rods for 40 and 50 gallon heaters are all pretty much the same length. Assuming you have a ceiling overhead, you'll want a segmented "flexible" anode rod. That's bunch of metal anode sections connected with a stainless steel cable. Don't worry about the length! It won't reach the bottom of your tank, and even it it did, it wouldn't be a problem.

The best metal to choose for a replacement depends on your water chemistry. If you have a plug style anode, a dot of weld bead in the middle of the hex plug would indicate magnesium, while a plain hex plug means aluminum. The manual I found doesn't show the anode, but it does show a pair of caps in the top cover, which makes me think you have one or maybe even two plug anodes under them. You may need to go digging through foam insulation under those caps to unearth it/them. If there's nothing there, you might have a ****** style anode on the hot tap.

I don't know why you think the 21/31 marking has anything to do with the size of the valve, but it doesn't. I've never seen a water heater drain valve in anything other than 3/4 NPT.

 

[BurtEggley]

Once you go anode rod shopping, you'll find that the rods for 40 and 50 gallon heaters are all pretty much the same length. Assuming you have a ceiling overhead, you'll want a segmented "flexible" anode rod. That's bunch of metal anode sections connected with a stainless steel cable. Don't worry about the length! It won't reach the bottom of your tank, and even it it did, it wouldn't be a problem.

The best metal to choose for a replacement depends on your water chemistry. If you have a plug style anode, a dot of weld bead in the middle of the hex plug would indicate magnesium, while a plain hex plug means aluminum. The manual I found doesn't show the anode, but it does show a pair of caps in the top cover, which makes me think you have one or maybe even two plug anodes under them. You may need to go digging through foam insulation under those caps to unearth it/them. If there's nothing there, you might have a ****** style anode on the hot tap.

I don't know why you think the 21/31 marking has anything to do with the size of the valve, but it doesn't. I've never seen a water heater drain valve in anything other than 3/4 NPT.

thank you. I assume it is 3/4 but when I see a fractional size marked on a plumbing valve, it may be indicating size. One possibility is that is the valve internal size when the ball is open. It looks to somewhere around a half inch.

 

[mike93lx]

I can't imagine they would use something other than 3/4.

I'd have the parts on hand to swap it. Worst case, it doesn't fit and you reinstall the original.

For the anode, I'd get a standard one and just swap it. Again worst case its long and you just cut it

 

[JSutter]

0000

 

[rharman]

I've used a segmented magnesium anode for years - it gets replaced every 2 years. Headspace is an issue so I went segmented with the first replacement. One replacement was quite long so I just snipped off the last segment. We have a water softener and that exacerbates the wear on the anode. Over time, I've figured 2 years is a good interval.

Here's a pic of my drain setup. it's all 3/4" brass. I added a ball valve and a hose bib adapter. Easy to drain - I drain 5-8 gallons every quarter - at least, I try to do it quarterly. The upper part of this plumbing won't matter to you. I have it tee'd as that's the return for our hot water recirculating.

I believe @nafterclifen is misinterpreting the manufacturer info. I think what they're describing is the choice of magnesium and aluminum and saying that, at some point, either may cause smelly water and you'll need additional measures to combat it.

 

[BurtEggley]

21/31 could be a date. I'll buy that.

 

[sgrammel]

I bought a 44" segmented rod for my Rheem 2018 water heater. Never changed out the rod..so first time. Looks pretty simple...only concern I have is getting the old one loose. Can't get a cheater bar on it because of clearance..so hoping a 1/4 Dewalt 20v impact driver will work...

 

[mike93lx]

I bought a 44" segmented rod for my Rheem 2018 water heater. Never changed out the rod..so first time. Looks pretty simple...only concern I have is getting the old one loose. Can't get a cheater bar on it because of clearance..so hoping a 1/4 Dewalt 20v impact driver will work...

No chance that a 1/4" driver will work

 

[rlitman]

I bought a 44" segmented rod for my Rheem 2018 water heater. Never changed out the rod..so first time. Looks pretty simple...only concern I have is getting the old one loose. Can't get a cheater bar on it because of clearance..so hoping a 1/4 Dewalt 20v impact driver will work...

I doubt it, but I've had no problem using pneumatic 1/2" impacts to do the job.

 

[sgrammel]

I doubt it, but I've had no problem using pneumatic 1/2" impacts to do the job.

I've got that too....hopefully I can get to the nut with the pneumatic..

 

[BurtEggley]

Milwaukee M18 3/8 with adapter, or 1/2 - either set to 3 or 4 using 5.0 battery or larger, or pneumatic 1/2". Milwaukee 3/8 and 1/2 have about the same torque output according to tests run by people.

 

[sgrammel]

I bought a 44" segmented rod for my Rheem 2018 water heater. Never changed out the rod..so first time. Looks pretty simple...only concern I have is getting the old one loose. Can't get a cheater bar on it because of clearance..so hoping a 1/4 Dewalt 20v impact driver will work...

I doubt it, but I've had no problem using pneumatic 1/2" impacts to do the job.

Well I have to say I am more than a bit surprised. The 1/4 Dewalt busted it loose..The rod was in way better shape that Imagined. Couldn't get it all the way out due to clearance issues, so just put it back in....The Rheem gas water heater was new 12/2017 so 8 years and the rod is in almost new shape...Guess I have good water here in Clark County WA

 

[mike93lx]

Well I have to say I am more than a bit surprised. The 1/4 Dewalt busted it loose..The rod was in way better shape that Imagined. Couldn't get it all the way out due to clearance issues, so just put it back in....The Rheem gas water heater was new 12/2017 so 8 years and the rod is in almost new shape...Guess I have good water here in Clark County WA

That's wild. Never would have guessed that. I've pulled a few anodes and they all took more than I think an impact driver could have done

 

[rlitman]

Well I have to say I am more than a bit surprised. The 1/4 Dewalt busted it loose..The rod was in way better shape that Imagined. Couldn't get it all the way out due to clearance issues, so just put it back in....The Rheem gas water heater was new 12/2017 so 8 years and the rod is in almost new shape...Guess I have good water here in Clark County WA...

Color me surprised too, but hey, I'll take the impact success for a win. As for the "new" rod, I'm not positive that's a great sign. If it's a factory aluminum rod and it's showing no signs of corrosion, that could be the corrosion control chemistry in your city water is working well, but it also means that the rod hasn't done much to protect your tank. The loss of anode metal is what proves the rod is doing it's job.

Seeing how well your rod is doing makes me pretty sure you need a more active rod. Either magnesium, or electronic.

 

[sgrammel]

Color me surprised too, but hey, I'll take the impact success for a win. As for the "new" rod, I'm not positive that's a great sign. If it's a factory aluminum rod and it's showing no signs of corrosion, that could be the corrosion control chemistry in your city water is working well, but it also means that the rod hasn't done much to protect your tank. The loss of anode metal is what proves the rod is doing it's job.

Seeing how well your rod is doing makes me pretty sure you need a more active rod. Either magnesium, or electronic.

I checked Rheem's website, based on my Serial Number, current rod is magnesium. When I drained some of the water from the tank it was clear (rather than rusty/cloudy).

 

[BurtEggley]

strange color. Looks almost like a copper pipe. Was the anode rod a separate rod or part of the hot water outlet?

 

[sgrammel]

strange color. Looks almost like a copper pipe. Was the anode rod a separate rod or part of the hot water outlet?

Separate rod.. The orangey stuff when dry was powdery and wiped right off. Rod was basically black.

I'd sure be interested in a professional plumber's input..

 

[rharman]

That's wild. Never would have guessed that. I've pulled a few anodes and they all took more than I think an impact driver could have done

First time I pulled mine, I used my 1970's era 1/2" Craftsman electric impact. It has some oomph. Now, a breaker bar works fine.

 

[mariom2019]

I've swapped out a few anode rods in my time and usually just stuck with the standard length for 50-gallon tanks. After my old aluminum one corroded, I changed to a segmented magnesium rod, which fit fine. Personally, I’ve always used 3/4" brass on the drains, never had a problem with fitment on any brand, including American Standard. Those stamped markings can be confusing, but every time I checked, it still lined up with 3/4" NPT threading.

If you run into trouble with the actual swap or want a pro opinion specific to Houston-area codes and setups, I know a lot of people reach out to Turbo Home Services for jobs like this. They’re pretty solid with quick appointments and straight answers.