Filling the water heater

[Glenn the fifth]

Hello all, glad spring is here (although still a little cool here near Seattle). This is my first "get the 5er ready for the camping season" with this camper. Last weekend I did all the prep work (good clean up inside and out, tires, lug nut check etc...). I was just thinking this morning about the water heater. Each late fall I take the zink anode (at least I believe it is made of zink) out of the water heater to drain it and clean it out. I leave it out all winter and plug the hole with a small round piece of wood so no critters get in there. I now have it reinstalled and ready for use. It my other trailers I simply ensured the bypass was shut and hooked up the water the first time we went camping. When doing that I just assumed the water heater filled it self up. I am now second guessing myself on that. Is there a better, more sure fire way to make sure your water heater has water in it before you turn on the heating element the first time you go camping? I don't want to burn up the filament. Thanks, Glenn

[RonD]

Just hook up the water at the park your at with the water heater switch in the off position, turn on the hot water at a sink. After you hookup the water hose and turn it on, you can hear the tank filling, when the fill sound stops, turn on a faucet in hot, when the remaining air is gone your ready, turn on the water heater switch

[Glenn the fifth]

Thanks Ron, thought that might be the right way and it is what I have done in the past. Just wanted to ensure I was being safe so as not to be sorry later...

Have a great camping season!

-Glenn

[GreatWhite]

Another simple option would be to open the blow-off valve at the top of the heater.. always nice to make sure it's not "welded" in place.

[mhs4771]

Or you can open the pressure relief valve on the WH while filling. Once water starts coming out the relief valve you know the tank is full. This method ensures the tank has water, just in case the by-pass valve didn't open as designed, or in some units without the single by-pass valve there is a series of 2, 3, or maybe even 4 in-line valves that must be in the proper positions.

[Carl n Susan]

Opening the Over Pressure Valve (OPD) on the water heater is the quickest and best procedure. Once you have water exiting the OPD (indicating the tank is full). Turn off the water supply, open the bathroom sink or shower hot water valve, and then close the OPD. Now you can turn the water back on, get the air out of the hot water system, close the bathroom valve(s).

This achieves two good things. One, the OPD valve is flushed of any mineral or sand particles to help it seat tightly. Two, this process ensures there is an "air cushion" at the top of the water tank which allows the expansion of the water volume as it heats. If you don't have an expansion space you will experience water dripping out the OPD (and down the side of your rig).

[Tom S.]

And don't forget to purify your water system before filling with water!

[mmgeol]

I always listen for the tank filling, and then open the pressure relief valve when full to make sure. Then turn on the water heater switch.
This is one of those times to always follow procedure, otherwise a costly repair or worse.

[Glenn the fifth]

Wow, thanks Carl (and others). I did not think of the need for the an air pocket, but understand why it is a good idea. Learned some more good stuff here again today!