This was our 2013 Jayco Flight Swift 198 RD


Thursday 8 September 2016

Smart Hot Water Heater Tank Drain

bottom left: smart drain assembly fitted

It became an annual November or December exercise to drain the hot water heater and water system to prevent it from freezing before we traveled south.  Winterizing the RV water system it is called. Draining the hot water heater is only a part of it. Most RVs have fitted the Atwood or the Suburban brand of water heater. Both manufacturers’ in-built hot water storage tanks have drains and these drains are closed up with a ½” NPT (National Pipe Thread) plastic plug.
First you switch the electric or gas to the hot water heater off. To drain the water you shut off the water supply as well, then you open the water heater maintenance door. It is probably located at the back or side of the RV and look for the drain plug and ignore the pressure relieve valve. But before you do anything stupid you go to the inside of the RV and open a cold water and a hot water tap to relieve water pressure and after you’ve done this, please leave the taps open.

Please, do not use the tank’s pressure relieve valve of the water heater to relieve the pressure unless you have an Ambulance standing by. The water spraying out of the relieve valve can be extremely hot and could, God forbid, spray right into your face. It is better to bleed or relieve the pressure in the kitchen sink.

In order to drain the water heater tank in every of our previous and present trailer, I had to remove the ½ inch NPT plug by using a 1 inch or 7/8 inch wrench or socket. That was not an easy thing to do, as there is not much room to fit the wrench or socket.  You drain all the water out of the tank and then remount the plug with a few layers of Teflon tape or a pipe joint compound.  This exercise you may have to do again in case you return home early to the Northern States or Canada in the middle or late March from the sunny South. Chances are that you’ll run into ice or snow with freezing nights. 
Removing and remounting the drain plug had become such a pain in the neck, so to speak and I have been thinking of a better way to do this. To simplify this draining procedure, I made up an easy to do draining assembly with shut-off valve, picture below.

Here is a list of what I used to make up a Smart Hot Water Heater Tank Drain:
1. One ½“ PEX x ½” NPT brass male adapter.
2. One mini PEX ball valve,
3. A short end of plastic PEX tubing (Maybe in red color, red color is for hot).  
4. Two ½“ PEX crimp fittings.

Tooling for making up this assembly you may have already in your house plumbing tool kit or a quick run over to your friendly neighbor or, to the Home Depot or Lowes will solve this problem. Hey, you can never have enough tools J

To seal the ½ inch NPT brass fitting to the tank drain port, I recommend using Whitlam (USA) pipe joint compound, which is good for gas and water joints and very easy to use. It’s more rewarding than Teflon tape.
It is important to clean the thread of the tank port of any old sealant/Teflon tape pieces etc. or it won’t adhere and you may end up with a leaky joint.

left: brass adapter / middle: PEX tubing / right: mini ball valve
bottom: two PEX crimp fittings

top: PEX tubing cutter / middle: red PEX tubing / bottom: box cutter could cut PEX tubing as well

two different PEX crimp tools

simple PEX crimp tool

top: removed drain plug / middle: replacement smart drain assembly / 
bottom Whitlam pipe joint compound

fitted smart hot water heater tank drain

attached a stainless steel braided toilet hose to guide the drained water

1 comment:

  1. This is really helpful in concern if the water heater is working properly when you wanted to relocate. Make sure you follow these step to check your water heater health. Heating and Cooling Oakville