Hot water heater on or off

[Dirt Sifter]

I'm in the Oaklevel and Kenandterry camp. Turn it on and leave it on LP most of the time when in camp.

[DouglasReid]

The definitive solution is a Tankless On-Demand WH. It only runs when you open a hot water valve.

We had a Girard Gen 1 unit that was very finicky. I replaced it with a Furrion unit that is digitally controlled and it works splendidly.

[Qwkynuf]

Originally Posted by Chaplain Kent

At the bottom of this thread is an article from RV life on how to save energy. It says leave WH off unless you need it. This reminded me that when we travelled in Europe and Asia there often was a switch in the bathroom to turn off WH. Further we like to sit under awning outside and dont need the fumes from the WH exhaust. So it is off and only on in the morning when we need it.

Counterpoint: It's not as simple as that. Unless you have a tankless "on demand" water heater, then this "savings process" means

(assuming 70deg ambient air temp)

• water heater tank has 8 gallons of water at 70deg
• user turns on gas or electric (or both)
• 8 gallons of water is heated up to, say, 120 degrees
• user consumes 2 gallons of water washing dishes
• user turns water heater off
• 8 gallons of water eventually cools back down to 70 deg
• user turns WH back on for shower
• 8 gallons is heated up to 120 deg again
• user takes shower, uses 5 gallons, turns WH off again
• water in tank cools down to 70 again
• etc, etc

Does that use more, or less energy than letting the thing heat up to 120, cycle off, cool down by 8 or 10 degrees, cycle back on, and repeat?

Seems like the energy that was used to heat (and reheat) the unused water would be a waste of energy that would need to be taken into account?

For us, we turn on both gas and electric when we get to the campground, and can easily get through 2 weeks on two 30# tanks of propane in our 21DS - and that includes hot water, furnace (supplemented with a small 750w space heater), and cooking on stovetop and oven - even in the winter with temps in the 35-45 degree range.

[MisterVick]

I leave the electric side on full time when parked with hookups and cycle the gas on and off based upon demand; showers mostly.

[NavyLCDR]

Originally Posted by MisterVick

I leave the electric side on full time when parked with hookups and cycle the gas on and off based upon demand; showers mostly.

Same here. Electric is on all the time if electricity is available and the trailer is occupied (which includes when it is parked in my driveway and plugged into a garage outlet).

I turn on gas side only when needed, whether or not electricity is available.

[Larry-NC]

Originally Posted by 5picker

On all the time whether on LP or electric.

I never know "when" I'm going to need it so turning it on as needed would never work for me.

Same for me. Even with shore power we sometimes use propane and sometimes use electricity. Have never used both, probably because we always use the campground showers.

[DouglasReid]

Originally Posted by Qwkynuf

Counterpoint: It's not as simple as that. Unless you have a tankless "on demand" water heater, then this "savings process" means.........................
Seems like the energy that was used to heat (and reheat) the unused water would be a waste of energy that would need to be taken into account?.........................

Several studies have shown that the gas used in the tankless WH is less than leaving a 6 gallon WH running constantly.

Using the electric supplied by the campground is obviously the least expensive way to go, but also the slowest recovery.

The coils in the tankless are very small, a few ounces not gallons. The Furrion inputs 60,000 BTU immediately upon opening the valve. It uses a mixing valve to lower the water temp to whatever setting we have set on the digital control.

Within 15 seconds we have an endless supply of hot water, meaning no more Navy Showers.

[dahagen]

Originally Posted by fonzie

On all the time.

X2

[ncebeemer]

X many--always on

[jimmoore13]

We boondock most of the time.

On the rare occasions where we have shore power, we run the electric hot water heater continuously.

When boondocking, our heater is on the curb side, and this means that it's very noisy when running on propane. Because of this, we turn it on about 15 to 20 minutes prior to use...and for dishes and such, we turn it off before use, once the water is hot. 6 gallons of hot water are more than enough for anything but a shower, and there's no reason to force the water heater to recover from smaller uses.

In our previous rig, a high-wall pop-up, the water heater was propane only, on the road side, so we'd turn it on first thing in the morning (after quiet hours), and turn it off at bedtime...so we didn't have to listen to it overnight.

In both cases, propane consumption is negligible.

[SailorSam20500]

When I have shore power available, the WH is on most o f the time. I will purposely turn it off if I think we are consuming close to the full 30 amps our trailer is wired for. For example, in colder weather when we have an electric heater running, and making breakfast with the coffee pot, microwave, etc. going. When the special high demand power need ends, I turn the WH back on.

[Chuck_S]

What are you calling “the bottom of this thread”?

Probably one of the advertisements below these threads that vary depending on time of day (or something). Hit the refresh thingie in your browser and they'll be different.

I'm not seeing anything to recommend turning the water heater Off until done with it which for us is when it goes back into storage. Once the water is hot it takes very little energy, electric or gas, to keep it hot.

I'd love to see the energy usage to maintain the water temperature in the heater. Not heat from ambient, keep it at set temp.

-- Chuck

[Nutz4OSU]

I always turn the gas heater on as soon as we’re parked. Once the water is heated up, I turn electric heater on and the gas heater off. If we’re both showering that evening, I’ll turn the gas on for quicker recovery, then turn gas off again once the showering is over.

[Qwkynuf]

Originally Posted by DouglasReid

Several studies have shown that the gas used in the tankless WH is less than leaving a 6 gallon WH running constantly.

Using the electric supplied by the campground is obviously the least expensive way to go, but also the slowest recovery.

The coils in the tankless are very small, a few ounces not gallons. The Furrion inputs 60,000 BTU immediately upon opening the valve. It uses a mixing valve to lower the water temp to whatever setting we have set on the digital control.

Within 15 seconds we have an endless supply of hot water, meaning no more Navy Showers.

I am not following what you are disagreeing with? In my post (that you quoted), I said "unless you have a tankless....", meaning "If you don't have a tankless".

There's no question that tankless are more efficient, but the subject of the thread is about whether or not to leave a conventional water heater powered on - my comments were about that.

To the folks that advocate turning the water heater off when you aren't using it, in order to not waste energy, do you do that at home? Do you only fire up that 40 or 50 gallon water heater a couple of hours before you want to do dishes or take a shower? Did you turn it off before you left to go camping for a week?

I'm not criticizing or ridiculing - I'm genuinely curious. I have never heard of doing such a thing.

[Foothills]

If you're one to leave it on all the time be sure to turn it off when the tank is drained-some leave RV plugged in to keep batteries charged. Not good for the WH.

[downsc123]

Originally Posted by Reverse_snowbird

We'd tend to turn it on about fifteen minutes before we need it and turn it off after we use it in our tt. The main reason we did that was to help keep the heat out of the trailer when the air conditioning was on.
If you're plugged in, there's no real reason not to leave it on. Propane is a different discussion.

The bold part got me thinking. My kids sleep in their bunks in the rear of the trailer (water heater is underneath the bunks - Alpha Wolf 26 DBH-l) and complain its hot with the AC set at 69 or 70 at night. Wonder if the water heater is contributing to that.

[CustomBuild]

Originally Posted by Chaplain Kent

... when we travelled in Europe and Asia ....

Did you ship a RV or T/T or rent a unit out there?

I'm curious because my plan is to ship to Europe and tour for a couple of years once Covid is a thing of the past. We're also thinking about China as there is a growing RV infrastructure, but I didn't think much about the rest of Asia outside of India, which also appears to be good for domestic RV'ing.

Too many places to go; not enough time.


Edited:
Actually, upon re-reading Chaplain Kent's post, I guess you are talking about switches in some kind of hotel or other accommodation and not a T/T or RV, because that would not be a sign you would be re-reading and it wouldn't be sometimes.

[Kstedman]

If you have a 50 amp RV you can leave it on the entire time. If it’s a 30 amp you may want to turn it off especially if your ac is running and if you use the microwave or a hair dryer it will trip the breaker.

[CustomBuild]

Originally Posted by kevinB24

Once you get to your destination and have 30 or 50amp power do you leave your hot water heater on for your entire stay or just turn it one when you need it, then turn it off when you are done using it?

Looks like a lot of comments on this topic, so I'll add one more

We have two tanks (long story) a six gallon and a four gallon. The 6 stays on 24/7 apart from in storage. The 4 is used only in colder climates to compensate for the noticeably colder incoming water. To clarify, the 4 is inline between incoming supply and the 6 gallon main tank.

[CustomBuild]

Originally Posted by RGrimm

I did add an Intellitec power management module that will automatically turn off the HW heater if the Microwave is turned on and then turns the HW heater back on 45 seconds after the microwave turns off.
-Russ

I had no idea these sort of smaller devices existed. I'd thought about trying to design my system around one or more regular 30A transfer switches and at the end of the day it was getting too complicated.

Sometimes on Amazon it's not if they have a product or not, it's if you know what to look for.