Draining water heaters

[maybesoon]

I've read a few posts about draining water heaters and the discussion about the water drain plus that isn't robust. My solution was to install two little items: for the drain plug, a brass spigot with a valve, threaded for a hose connection and for the pressure relief an adapter to allow a garden hose to be put on quickly and easily.

Now draining the water heater takes nothing more than removing the brass cap, putting on a water hose and opening the valve. I used high temp teflon thread tape and that avoids any metal to metal corrosion.

For flushing the water tank, attaching a hose to the pressure valve, opening it and setting it to open lets me back flush through the valve and out again through the drain valve. This works perfectly, get the sediment out and eliminates the hassle.

I thought I post this because I've read about folks using buckets, spraying water all over and things like that. Another benefit is that reusing the water is now simple. Now that everything is easy, my hot water always reads as good as my cold water, below 50 ppm.

[LK23]

If you previously had a plastic drain plug in your hot water heater, you may want to re-think your recent change. If your hot water heater is aluminum, a brass drain plug will cause a metallic reaction between two dissimilar metals effectively freezing the brass plug in place. Thus the reason for the plastic drain plug. Personally, I hate the plastic plugs. I have had several problems with broken or leaking plastic plugs.

[maybesoon]

Originally Posted by LK23

If you previously had a plastic drain plug in your hot water heater, you may want to re-think your recent change. If your hot water heater is aluminum, a brass drain plug will cause a metallic reaction between two dissimilar metals effectively freezing the brass plug in place. Thus the reason for the plastic drain plug. Personally, I hate the plastic plugs. I have had several problems with broken or leaking plastic plugs.

Check your original fitting, it is probably not aluminum. Maybe I should clarify: I did not remove the original fitting, only added to it. The original plastic plug was already going into a brass fitting so that means my solution is brass to brass, likewise for the pressure relief valve.

Never underestimate the ability of manufacturing to go cheap and then explain the result as a benefit. Looking at other things in our motor homes we can see lots of corner cutting yet the manufacturer can explain all of them as benefits.

I have yet to see an aluminum pressure relief valve. The same applies to the drain fitting. Most new residential water heaters are aluminum yet the fittings are brass. If the reason for the plastic drain plug was corrosion resistance, then surely they wouldn't use a brass pressure relief valve or brass drain fitting.

While the contact between brass and aluminum can cause some reaction, we're talking about a water heater where the amount of aluminum to brass is quite small so no worries. If we were talking about close tolerance specifications like aircraft or something like that, ok, but even then the solutions are simple and the problem easily overcome by folks like us.

My solution only adds brass extensions where brass already exists. Make thousands of water heaters and then calculate the cost of a plastic drain plug vs brass. It adds up real fast.

Ever see a plastic drain plug in a residential water heater? Only on the cheap ones.

[maybesoon]

I just checked on several other RVs and motor homes and all of them have brass pressure relief valves and brass drain fittings on their water heaters.

This would include Atwood (which I have).

That should clear up any misconceptions out there about plastic drain plugs being used to prevent corrosion to aluminum water heaters. The manufacturer is already using brass fittings and my solution only adds to the ends of those already in place.

So if you are hesitant to change the plastic drain plug, take a look at what that plastic drain plug goes into, it is probably brass, not aluminum. The manufacturer is saving money using plastic.

Hopefully this information helps others.

[hamguy]

Originally Posted by LK23

If you previously had a plastic drain plug in your hot water heater, you may want to re-think your recent change. If your hot water heater is aluminum, a brass drain plug will cause a metallic reaction between two dissimilar metals effectively freezing the brass plug in place. Thus the reason for the plastic drain plug. Personally, I hate the plastic plugs. I have had several problems with broken or leaking plastic plugs.

I have had plastic plugs in every WH in every RV I have had. I usually carry a spare (reminding me that I used my spare and didn't replace it. Trip to Ace Hdwr is in order). Minimal cost, no corrosion or other bad stuff and they do the job nicely. No need to mess with them. Just don't over tighten.

[NatureCalls]

Love the idea of a connection on the relief valve for back-flushing. I installed a water heater drain valve I got online to replace the dreaded plastic plug. I had some plastic tubing left over from an in-line filter kit that fits perfectly inside the valve and directs water where ever I want, but the idea of a hose is probably much better. The previous owner of our MH treated it like a dog house for humans and one of the many neglected items was that plug. It was covered in "pipe dope" and leaked all the time, adding to the rust problem in the box.

[rvten]

I flush mt HW through the drain outlet. Have a small adapter that lets me flush out the tank. Get more crude out that big drain than a little drain hole.