Hot water heater zinc

[No Mast]

So our previous owner apparently didn't know the hot water tank had a zinc. The old one is frozen in place and won't budge. As I see it I have two options.
1. Impact wrench
2. Corrosion X and patience

I'm concerned that the impact wrench may do more harm than good. Any suggestions?

 

[Larry M]

What model and manufacturer water heater?

I'd say no on the impact wrench. You might be looking at a new water heater if it's glass lined as ours is. The magnesium anode is the "hot water" out at the tank.

Here are 3 anodes: new, after 3 years and I waited too long.

 

[No Mast]

It's a torrid, with the zinc on top of the tank. I forget the model, maybe vs-20. I have the replacement magnesium zincs and yes they are long ones for sure

 

[RT Firefly]

Greetings,
Mr. NM. I agree. NO impact wrench. I have found through many years of experience that rusted/frozen nuts and bolts can usually be "coaxed" with careful application of heat via a torch.

There are as many techniques and degrees for heating as there are torches. Some varieties include: broad gentle heating with a propane "plumbing" torch to pinpoint spot heating with an oxyacetylene unit. Application will depend on the particular "problem".

I suspect in your situation, brief spot applications of a VERY hot, focused flame directed to the female fitting will loosen the anode.

 

[psneeld]

What kind of metal, threaded into what kind of metal?

Knowing gives better options....especially if softer like brass.

 

[sdowney717]

Greetings,
Mr. NM. I agree. NO impact wrench. I have found through many years of experience that rusted/frozen nuts and bolts can usually be "coaxed" with careful application of heat via a torch.

There are as many techniques and degrees for heating as there are torches. Some varieties include: broad gentle heating with a propane "plumbing" torch to pinpoint spot heating with an oxyacetylene unit. Application will depend on the particular "problem".

I suspect in your situation, brief spot applications of a VERY hot, focused flame directed to the female fitting will loosen the anode.

Something like an acetylene torch to get it red hot super quick, a lot of heat quick in a small spot for a short time usually does work well.

I would try the impact wrench first, you think that is too much stress on the tank?
I wanted to change out our rod on the house gas water tank. A breaker bar did not work. An impact did not work. I let it go, and in a year, It started to leak. When I looked into this, some forums said the OEM puts these on so tight they are almost impossible to remove. after I replaced the house tank, I tried to remove the rod to see what it looked like. It refused to budge, even was bending the tank where I tried to secure it using the other fittings.

On my boat, my 12 gallon tank is aluminum, and did not have a rod. It did have a cheap plastic drain. I removed the drain and installed an RV magnesium rod.

 

[RT Firefly]

Greetings,
Mr. 717. "...to get it red hot super quick..." Sorry, I strongly disagree in this case. Red hot is WAY too hot IMO for this application. As I posted in #4 above, brief application of spot heat will suffice. Touching the tip of the flame in multiple places around the periphery of the fitting should work. One may have to repeat the process several times, wrenching while hot and allowing the fitting to cool or shock cooling with a wet rag in the interim.

 

[rwidman]

Something like an acetylene torch to get it red hot super quick, a lot of heat quick in a small spot for a short time usually does work well..

Heat applied to something you are trying to remove makes it expand and become even harder to remove. And a torch in a confined space on a boat (particularly a gasoline powered boat) can be pretty dangerous.

There are penetrating oils and there are penetrating oil sprays that also cool where you are spraying. I have used them and they work. Cooling the nut will shrink it and make it easier to remove. The trick is, you have to use a lot of spray for the cooling to have an effect.

Look in the auto parts store.


BTW: Most folks don't bother with the water heater anode, especially on a boat. You might have to remove the water heater from the boat to replace it.

 

[No Mast]

psneeld: I don't know the metals. Wont be at the boat for a few days to look. I have no clue what the tank is beyond painted metal. I can see if it's magnetic, how else to tell?

WesK: all diesel, no worries there.

All: So i don't have an oxyacetylene torch so I can try the propane torch if corrosion X doesn't do it first.

 

[sdowney717]

Heat applied to something you are trying to remove makes it expand and become even harder to remove. And a torch in a confined space on a boat (particularly a gasoline powered boat) can be pretty dangerous.

There are penetrating oils and there are penetrating oil sprays that also cool where you are spraying. I have used them and they work. Cooling the nut will shrink it and make it easier to remove. The trick is, you have to use a lot of spray for the cooling to have an effect.

Look in the auto parts store.


BTW: Most folks don't bother with the water heater anode, especially on a boat. You might have to remove the water heater from the boat to replace it.

The male part fits into the female part, so your heating the female part hotter than the male part. Regardless, what happen is the heat not only busts and crushes the rust crystals, the metal also is expanding and refitting itself one part to the other, so then as it cools metals shrink and so on threaded fittings fitting, the shrink easily loosens the 2 parts. And the rust that expanded locking the parts is crushed and is no longer locking the parts.

I can not even count , it is so many parts , the very many corroded and stuck tight metal parts my heating them has allowed me to loosen.

 

[Larry M]

...I have no clue what the tank is beyond painted metal. I can see if it's magnetic, how else to tell?...

When you get to the boat next, post a picture. We maybe able to ID the heater and the manufacturer even maybe able to help.

Raritan has plastic of some type on the anode (pictures I posted) next to the threaded section going into the water heater. Heat maybe an issue on those anodes.

EDIT: My bad a re-read the thread and see it's a Torrid water heater.

Great water heaters. They're glass lined and foam insulated. I'd call Torrid.

 

[sdowney717]

Greetings,
Mr. 717. "...to get it red hot super quick..." Sorry, I strongly disagree in this case. Red hot is WAY too hot IMO for this application. As I posted in #4 above, brief application of spot heat will suffice. Touching the tip of the flame in multiple places around the periphery of the fitting should work. One may have to repeat the process several times, wrenching while hot and allowing the fitting to cool or shock cooling with a wet rag in the interim.

Well, if glass lined tank then it would stress the glass liner even getting the threaded fitting that hot for a very short time.
An acetylene flame can heat up a very small part red hot very very quick. I just do whatever it takes to do what I need to do to get something done on my own stuff. Simply heating the steel end of the rod real hot that sticks above the tank is likely enough to swell it up inside the threads so that when it cools, you can spray some rust buster on it and it will unscrew without hurting the tank. And putting some wet towels around the tank fitting is a good idea too.

Heat works cause it makes metals expand, so that when they cool and shrink the parts can be easily unloosened.

 

[dhays]

zinc in a hot water heater...? Something else I need to check.

 

[Larry M]

zinc in a hot water heater...? Something else I need to check.

No zincs in the water heater, anodes and not all heaters have them.

 

[RT Firefly]

Greetings,
My final opinion on this... IF the female fitting on the tank is brass/bronze, heating it to red heat is pretty well at it's melting temperature.

Mr. LM. Good point on the plastic parts.

Mr. NM. A propane torch may be too broad a flame and will possibly heat both the female fitting AND the anode. A self defeating and potentially destructive exercise IMO. You might be best to stick to the penetrants for this repair. I have both a propane head and a smaller butane torch (has a well defined very hot cone) on board.

 

[No Mast]

No zincs in the water heater, anodes and not all heaters have them.

Um... A "zinc" is a sacrificial anode no?

 

[Larry M]

Um... A "zinc" is a sacrificial anode no?

You're right but I have always looked at zincs having zinc as the major ingredient and anodes having aluminum or magnesium as their majors.

 

[No Mast]

You're right but I have always looked at zincs having zinc as the major ingredient and anodes having aluminum or magnesium as their majors.

I understand what you're saying. But I think most people use "zinc" to mean sacrificial anode. The composition of which is really a factor of choice and environment.

 

[dhays]

I understand what you're saying. But I think most people use "zinc" to mean sacrificial anode. The composition of which is really a factor of choice and environment.

You are right, I was using the term "zinc" as a generic term for anode. I actually have been trying to use the more accurate term "anode" when referring to non-zinc anodes. So, I appreciated Larry's clarification.

 

[sdowney717]

If you watch this video, you will see the inside of a glass lined tank completely destroyed by rust, due to the magnesium anode wasted away.

Says don't go beyond 3 to 5 years in checking the magnesium anode.
For glass lined tank, you would think that glass would stop the rust, but nope, does not. Must be the glass layer cracks in use, or defective, or just not thick enough.
OEM dont want your water heaters to last too long. Likely planned to break after 10 years for ones in your home.

One on my boat is solid aluminum. It has been ok since 1998. I did pull off the plastic drain and screw in a magnesium anode about 3 years ago.