Adding electric heat element to gas water heater

[TurnThePage]

Because my old travel trailer may need to be permanently occupied for the next 6 months or so, I'm considering adding an electric heating element to the gas only water heater. The tank is aluminum, and it looks like the available kits use brass fittings. I'm concerned about galvanic corrosion. Anybody have experience with these things?

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Thanks Doug!

[Grit_dog]

dougrainer wrote:
He states Aluminum tank, That means he has an ATWOOD heater. Atwood Heaters have NO Anode rod at all. They are NOT needed on the Aluminum tank. Only Suburban Water heaters have and require the Anode rod. If you install a HOT ROD on a ATWOOD tank, it would be best to remove the element every 6 months or so, to prevent galling and also to drain the Water heater. Installing a HOT ROD eliminates the drain system on the ATWOOD water heater. Galling should not happen in 6 months or less, so keeping the threads free is a good idea. Doug

Thank you.
The keyboard plumbers here aren't any better than the keyboard mechanics...

[dougrainer]

He states Aluminum tank, That means he has an ATWOOD heater. Atwood Heaters have NO Anode rod at all. They are NOT needed on the Aluminum tank. Only Suburban Water heaters have and require the Anode rod. If you install a HOT ROD on a ATWOOD tank, it would be best to remove the element every 6 months or so, to prevent galling and also to drain the Water heater. Installing a HOT ROD eliminates the drain system on the ATWOOD water heater. Galling should not happen in 6 months or less, so keeping the threads free is a good idea. Doug

[dougrainer]

agesilaus wrote:

Boon Docker wrote:
Teflon or plumbers tape is used to make a good seal. It will not slow corrosion.

That's right, put Teflon tape on some threads, insert the threaded connection and then remove. Look at the condition of the Teflon, what there is left of it.

Also I suspect that the heating element need to make an electrical connection via the threaded nipple.

The magnesium anode is the best plan but be warned it may need to be replaced in a short time period, months maybe not years.

120 Elements need NO connection for the threads. The 120 element is standard HOT and NEUTRAL. Doug

[agesilaus]

Boon Docker wrote:
Teflon or plumbers tape is used to make a good seal. It will not slow corrosion.

That's right, put Teflon tape on some threads, insert the threaded connection and then remove. Look at the condition of the Teflon, what there is left of it.

Also I suspect that the heating element need to make an electrical connection via the threaded nipple.

The magnesium anode is the best plan but be warned it may need to be replaced in a short time period, months maybe not years.

[Boon_Docker]

Teflon or plumbers tape is used to make a good seal. It will not slow corrosion.

[wa8yxm]

There is also a 10 gallon version

I would use several layers of plumber's tape..

https://www.homedepot.com/p/Valterra-6-Gal-HR6-Hott-Rod-Conversion-Kit-DGR6VP/309717523

[agesilaus]

pianotuna wrote:
There is one kit that includes a magnesium rod to protect the aluminium.

That will work

[Grit_dog]

$20 says you won't use anywhere near $120 (cost of a hot rod kit) in propane heating your water for 6 months.
Something to consider.

[midnightsadie]

wrap the threads with teflon tape good. slow things down

[pianotuna]

There is one kit that includes a magnesium rod to protect the aluminium.

[agesilaus]

Then pull the element and see if you notice any corrosion on the threads. It none then screw the element back in and check again in another 3 months.

Unfortunately the corrosion will occur on the aluminum side not the brass side. Aluminum will form the anode. I'd expect corrosion to occur at the contact zone between the brass and aluminum.

If the tank has a sacrificial anode, which it probably does not in a propane only heater, that may corrode instead of the aluminum.

[TurnThePage]

Yeah, I've already ordered a kit and will likely take that approach.

Thanks All!

[opnspaces]

I may be wrong but I don't think galvanic corrosion happens very fast.
I would probably buy a electric element and screw it into the tank. Then after 3 months turn off the water heater and let the tank cool. Then pull the element and see if you notice any corrosion on the threads. It none then screw the element back in and check again in another 3 months.
After your 6 months remove the element and put the plastic drain plug back in.