Atwood water heater drain plug tightening

I've never wrapped PTFE tape on it.

I could be way off base with this but! I do believe the tank fitting itself is tapered not the plug.

I have also found that the feel is different using the nylon plug vs. the anode rode system in Suburban heaters.

I wrape my nylon plug with the tape and just snug it up, no leaks so far.

Start by checking the threads on the tank. You can pick them clean with something soft like a toothpick. Vinegar also helps remove any scale. I bought new OEM nylon plugs but still need to wrap with 2 or 3 turns of thin thread tape. When my plug is tightened there are no exposed threads and little or no gap between the tank and the end of the plug.

might buy a copper pipe cleaner tool. its round a 3/4 inch size should fit the hole, its a round wire ball works good for cleaning the gunk out of the threads.

The ONLY way the tank thread could be damaged is if someone used a Metal/Brass plug and stripped the Aluminum threads. I use this and have for 40 years. Doug

https://www.homedepot.com/p/RectorSeal-1-75-oz-5-Pipe-Thread-Sealant-25790/100144191?source=shoppingads&locale=en-US&&mtc=Shopping-CM-F_D26P-G-D26P-026_001_PIPE_FITTING-MULTI-NA-NA-SMART-2998850-WF-PIPE_AND_FITTINGS_New_Engen_PL3_Live&cm_mmc=Shopping-CM-F_D26P-G-D26P-026_001_PIPE_FITTING-MULTI-NA-NA-SMART-2998850-WF-PIPE_AND_FITTINGS_New_Engen_PL3_Live-71700000094213694-58700007814434200-92700071019453829&gclid=Cj0KCQjw-daUBhCIARIsALbkjSZBiasgA2qlVS8BvFXrBQf9GpMDI3Snd9o3e9PzRtbQUc-BYXdK1egaAi7PEALw_wcB&gclsrc=aw.ds

craig7h wrote:
I could be way off base with this but! I do believe the tank fitting itself is tapered not the plug.

I have also found that the feel is different using the nylon plug vs. the anode rode system in Suburban heaters.

I wrape my nylon plug with the tape and just snug it up, no leaks so far.

Not how standard threaded pipe threads work.

Standard pipe threads have a taper (NPT is the standard) on both the "fitting" and the "plug".

There is non tapered pipe threads and a few other standards but those are typically not employed on typical and normal "household" plumbing.

See HERE for detailed info on pipe threads.

With Attwood water heaters you have a aluminum tank, Suburban you have steel tanks.

Attwood tanks the correct plug is a NYLON plug, that plug is tapered and as you turn it into the tank the taper engages and it gets more difficult to turn.

Nylon plugs are used for several reasons..

Nylon does not react with aluminum.

Nylon deforms easily which protects the soft aluminum tank threads from damage.

Nylon conforms (molds to) easily to the tank threads making a seal to the tank threads without the need for a pipe sealant.

Nylon has a low friction coefficient which means there is no need to use "Teflon" (Teflon tape does not really create a seal, it reduces the friction coefficient and allows you to keep turning the fitting past the point you would get with a dry fitting).

Nylon since it deforms some each time you tighten it, will over time the plug will wearout to the point you can screw it in all the way (no threads showing) and no longer seal at that point. When it gets to the point of no longer sealing, throw it out and replace with a new nylon plug and you will be good as new.

New nylon plugs can be had for a couple of dollars each and are much cheaper than replacing the entire water heater.

Pack of two plugs at Amazon is $10 and will last you many, many seasons..

HERE

I am still using the original nylon plug in my Attwood and that water heater is over 10 yrs old.

Just get a new plug if it’s wore out.

And fwiw, Teflon tape or pipe dope does seal or help seal the connection.
Otherwise one could use soap/wax/oil etc if it was only to lube the threads.

That said, many NP thread connections will seal up just by way of the tapered threads. And many won’t.

I run a pipe tap lightly through the aluminum threads to clean off the accumulated oxide, and use a plastic pipe approved PTFE paste on the nylon. No leaks to date.

Just a tip: If you need a new drain plug for a Dometic/Atwood water heater and there's no RV shop handy, a CPVC plug from a hardware/big box store will work fine as a substitute.

Oh, and another tip: Always buy two plugs and store one right in the water heater cabinet. Otherwise you'll never remember where you put it when you need it. ;)

As another source of supply, I found genuine nylon plugs at Tractor Supply in their irrigation supply section. They were less than $2 each and work great.