Atwood water heater drain plug tightening

[Missionstreet]

Please correct me if I'm wrong anywhere.

So I've got some "OEM" atwood plugs for my water heater that appear to be without any taper (I've read this is apparently normal for what I'm told these are -- "soft" nylon).

Several wraps of PTFE tape and I'm tightening with no felt change in resistance.
Besides a leak or damaged plug, is there any way the tank could be damaged? Got about 30% thread left exposed on plug.

[Grit_dog]

JimK-NY wrote:

ewarnerusa wrote:
I have always had to use tape to get a good seal between nylon plugs and my Atwood water heater. It seems to me like the nylon plugs would not need tape, but every season when I go over the system and don't tape the plug, water slowly leaks from the plug. Depressurize, remove, tape, reinstall plug, no leak. I've gone through a handful of plugs over the years, so it's not like it was one janky one that leaked.

That has been my experience exactly. Old or new plugs have made no difference. Two or three wraps of thin teflon tape ends the leaking.

Nope, GDE says that won't work. Doesn't seal threads...lol.

[Dutch_12078]

Missionstreet wrote:

Dutch_12078 wrote:
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. 😉

It seems like whatever I REALLY need is never available ?? in a "store"

I could not find cpvc in this fitting size at the big box!

I've found them for myself and other folks several times over the years in Ace or TrueValue hardware stores.

[JimK-NY]

ewarnerusa wrote:
I have always had to use tape to get a good seal between nylon plugs and my Atwood water heater. It seems to me like the nylon plugs would not need tape, but every season when I go over the system and don't tape the plug, water slowly leaks from the plug. Depressurize, remove, tape, reinstall plug, no leak. I've gone through a handful of plugs over the years, so it's not like it was one janky one that leaked.

That has been my experience exactly. Old or new plugs have made no difference. Two or three wraps of thin teflon tape ends the leaking.

[ewarnerusa]

I have always had to use tape to get a good seal between nylon plugs and my Atwood water heater. It seems to me like the nylon plugs would not need tape, but every season when I go over the system and don't tape the plug, water slowly leaks from the plug. Depressurize, remove, tape, reinstall plug, no leak. I've gone through a handful of plugs over the years, so it's not like it was one janky one that leaked.

[Gdetrailer]

Missionstreet wrote:

Dutch_12078 wrote:
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. 😉

It seems like whatever I REALLY need is never available ?? in a "store"

I could not find cpvc in this fitting size at the big box!

^^^THIS^^^

Man, where is the "like" button?

Needed a fitting while camping out of town once, visited every single big box store I could find and not once could I find what used to be a standard stocked fitting.. Started fitting a whole bunch of different fittings together in the stores but still was not able to make it work..

Wasted a lot of camping time, a lot of fuel and a lot of brain cells and finally resolved myself to the fact that I would need to continue camping without water to my toilet for the rest of the week until I was able to go home and order the correct piece needed from Amazon..

Retail stores have removed pretty much anything the computer system deems as "slow moving" from inventory. If it sits on the shelf too long, it no longer gets reordered after the last part sells.

Often takes visits to both Home Depot and Lowes in order to get most of the parts needed to do a project but there almost always is one or two items that both stores do not carry.. A very sad state of affairs..

[Missionstreet]

Dutch_12078 wrote:
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. 😉

It seems like whatever I REALLY need is never available ?? in a "store"

I could not find cpvc in this fitting size at the big box!

[Dusty_R]

I don't remember make or type of water heater, but a I put a quarter turn valve on our mh water heater, then all I have to do is open the valve to drain it. Down side, can't close cover with drain open.

[Traver8]

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.

[Dutch_12078]

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. 😉

[stevenal]

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.

[Grit_dog]

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.

[Gdetrailer]

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.

[dougrainer]

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=shopping...

[midnightsadie]

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.