How do I know if my water heater work on 120V or not?

[mlafleur]

Hello every one,


Simple enough question: How do I know if my water heater (Dometic 6 gallon) works on both 120VAC and propane or not? There is only one switch to turn it on or off, and there is both a 120V line going to the W/H and breaker in the 120V distribution panel.
The W/H works great, delivering hot water as expected, whether we boondock or if we're on shore power. The thing is I was never sure if it works on AC at all. How do I find out?


Thanks,


Maurice

[bubbles]

Originally Posted by mlafleur

Hello every one,
Simple enough question: How do I know if my water heater (Dometic 6 gallon) works on both 120VAC and propane or not? There is only one switch to turn it on or off, and there is both a 120V line going to the W/H and breaker in the 120V distribution panel.
The W/H works great, delivering hot water as expected, whether we boondock or if we're on shore power. The thing is I was never sure if it works on AC at all. How do I find out?Thanks,Maurice

Make sure there is cold water in the water heater tank leave the inside switch off and have 120Vac to the RV check that the switch shown is ON and test the water is getting hot at a faucet. Do not close the switch shown without water in the tank.

[wmtire]

Bubbles gave you good advice for a Suburban brand water heater. I know you said you have a Dometic brand(not Suburban), but can you make sure. If you are going by documentation included with the RV instead of physically confirming....you very well could have a Suburban brand.

A picture posted here of the water heater will tell us all as we know the difference between a Dometic and a Suburban just by looks.

Sent from my SM-A025A using Forest River Forums mobile app

[bubbles]

Originally Posted by wmtire

Bubbles gave you good advice for a Suburban brand water heater. I know you said you have a Dometic brand(not Suburban), but can you make sure. If you are going by documentation included with the RV instead of physically confirming....you very well could have a Suburban brand.
A picture posted here of the water heater will tell us all as we know the difference between a Dometic and a Suburban just by looks.
Sent from my SM-A025A using Forest River Forums mobile app

I overlooked the Dometic and went with a suburban due to a Georgetown MH. The Op also said there was only one inside switch and I thought dual source Dometic/Atwood water heaters had both switches inside the unit. Oh well. Live and learn.

[wmtire]

Originally Posted by bubbles

I overlooked the Dometic and went with a suburban due to a Georgetown MH. The Op also said there was only one inside switch and I thought dual source Dometic/Atwood water heaters had both switches inside the unit. Oh well. Live and learn.

I am thinking the OP may very well indeed have a Suburban so your advice is prudent. The pic will confirm.

This thread we keep in the FAQ subsection explains in more detail the electric mode of heating for a Suburban and the switch you showed for such

https://www.forestriverforums.com/fo...ad.php?t=36197

[mlafleur]

Correction to my original post: my W/H *is* a Suburban, not a Dometic, my bad. I will do the check Bubbles suggested.
M

[mlafleur]

What do you know? 5 years of rving and snowbirding only to find out today I never used electricity on my water heater.
I went ahead and turn the gas switch off, and turn the electricity switch on, and voilà! I didn't have to wait very long: after I turned on the electicity, I could hear the W/H start to "sing" like an electric kettle. It tells me it is working.
Why don't they put that switch inside, on the "control panel" along with other controls? Can one extend the wiring to have that switch inside?


Final question: how effective is the electric water heating system? Certainly not as much as gas, but enough to take a shower, or do the dishes for example?


Thanks,


Maurice

[Mr. Dan]

Originally Posted by mlafleur

What do you know? 5 years of rving and snowbirding only to find out today I never used electricity on my water heater.
I went ahead and turn the gas switch off, and turn the electricity switch on, and voilà! I didn't have to wait very long: after I turned on the electicity, I could hear the W/H start to "sing" like an electric kettle. It tells me it is working.
Why don't they put that switch inside, on the "control panel" along with other controls? Can one extend the wiring to have that switch inside?


Final question: how effective is the electric water heating system? Certainly not as much as gas, but enough to take a shower, or do the dishes for example?


Thanks,


Maurice

I want that electric element switch outside because it's next to where I stand to hook up my water hose. So I hook up the hose (water heater is already full from last trip) and flip that switch. I'm done. When I get ready to leave, I turn that switch off and unhook my hose and I'm done. I don't turn my water heater on and off but those times.


Effectiveness? I only use the propane portion IFF 2-3 grandkids are in line to shower consecutively. Otherwise, the electric element is all we need for hot water.

[Rhumblefish]

Electrical side heating is pretty effective, mlafleur. Just has to heat OVER 160° or so (and that it does, quite). It's just not necessarily quite as fast as gas (since gas burn temp is
higher than the resistance electrical heating unit), though this is more a function of heat exchanger design, et al. The electrical heater is entirely encapsulated inside the water of the HWH, so exchange is likely more efficient as a percentage of exchange, as opposed to gas burn, which happens outside of the water.

But this is only for startup (from a cold tank to a hot tank). Once the tank is at temp and is cruising, seems like the difference is more negligible.

Def enough to do dishes and take a shower - the electrical heater is taking the water up to HWH temp standard (limited by the thermostat), just like the gas heater.

Having Both gives a camper a little flexibility, based on your setup. If you're plugged in, you have hot water via the electrons flowing into your trailer with no additional cost (unless you're being metered for use). If you're boondocking, you can go pure propane to keep any drain off of your electrical system, and if you've got a house full of dirty campers, you can use 'em both in tandem to decrease recovery time on your hot water supply.

I'd say the two switch style (one inside, one on the face of your heater) was a safety "feature" - but it's more likely a result of system design. On the one switch setup, the HWH has its own switch can be for simpler trailers (and the HWH is only energized when you flip it externally), and the two switch model (with an internal switch on the house side) being laid in by the trailer builder for convenience ... and potentially a little safety, to make sure the HWH is completely full of water before energizing the electrical element (as that thing will burn if there's no water in the HWH).

The fact that some models have a switch on their faces and some do not show that there's not necessarily any particular overall rhyme or reason, it's just how the HWH manufacturers' philosophies have developed and how that applies to the units they deliver. Switch on the inside, however, is a reflection of the coachbuilder.

I, for one, appreciate the two switch system, as well as the pinned switch on the face of the HWH itself.

of course, I also like fooling with the thing, and diligently empty my HWH after camping, as well as filling it with fresh each time.

Just my .02, hope this helps.

[RCCS]

miafleur I did not have an inside switch on the camper we bought so I added one. I found the relay on Ebay item number 10029431903 for less than $17.00. Installed it in a electrical box with cover that had enough room for clearance and mounted it behind the electrical breaker/fuse panel in our camper. Ran a wire from the breaker in the panel to the relay and spiced it to the wire I removed from the breaker (only need to use the hot wire, not the neutral) and ran a 12 volt DC circuit to the 12volt terminals of the relay to a switch I added to switch panel. Now I have control of the water heater from inside the camper as well as the switch on the heater itself. I always turn the switch in the heater off at the end of the camping season when winterizing the camper and do not turn it on in the spring until I am sure the heater is full of water. I do not drain the heater between trips during the camping season because we go every weekend or at least every other weekend camping.

[BehindBars]

Originally Posted by mlafleur

What do you know? 5 years of rving and snowbirding only to find out today I never used electricity on my water heater.
I went ahead and turn the gas switch off, and turn the electricity switch on, and voilà! I didn't have to wait very long: after I turned on the electicity, I could hear the W/H start to "sing" like an electric kettle. It tells me it is working.
Why don't they put that switch inside, on the "control panel" along with other controls? Can one extend the wiring to have that switch inside?


Final question: how effective is the electric water heating system? Certainly not as much as gas, but enough to take a shower, or do the dishes for example?


Thanks,


Maurice

We have a Sunseeker with Atwood/Dometic water heater. It comes with the electric and gas water heat switches side by side on the indoor “convenience” control panel. If I had the Suburban set up, I would surely be working on a way to bring that electric water heat switch to a convenient location inside.

As for effectiveness, we use only the electric water heat element any and all the time we are on shore or generator power. With the electric on, we never need to use the propane side. At least with the 6 gallon Atwood/Dometic, the electric recovery time is plenty quick for us to take back to back showers.

[bubbles]

Originally Posted by mlafleur

Final question: how effective is the electric water heating system? Certainly not as much as gas, but enough to take a shower, or do the dishes for example? Thanks, Maurice

Probably so but you have to remember that your tank is only 6 gal and the real test would be the recovery time as the hot water is being used. It is recommended that both methods of heating be used for faster recovery when prolonged use is the order. It does not hurt (Suburban recommended) to have both methods on at the same time. How long can the hot water last for a particular task?? All of the Georgetown's I'm familiar with have 10 gal. water heater tanks. Don't know if your GT year does or not. Are you sure it's just 6 gal.?

[bikendan]

Originally Posted by mlafleur

What do you know? 5 years of rving and snowbirding only to find out today I never used electricity on my water heater.

Why don't they put that switch inside, on the "control panel" along with other controls? Can one extend the wiring to have that switch inside?

If you had the Atwood/Dometic WH, you would have inside switches for both propane and electric. Or if you had one of the newer Suburban WHs, they have an inside switch for the electric side.

[mlafleur]

The W/H us a 6 gallon, as per the attached pic.
M

[Mr. Dan]

Originally Posted by mlafleur

The W/H us a 6 gallon, as per the attached pic.

So you were right about the 6 gallons in your post 1.

[Flybob]

Just be sure to turn the electric portion off when breaking camp as mentioned above. If leave it on and connect to shore power without water in it, it will burn out the element quickly.

[Larry-NC]

Originally Posted by Rhumblefish

The fact that some models have a switch on their faces and some do not show that there's not necessarily any particular overall rhyme or reason, it's just how the HWH manufacturers' philosophies have developed and how that applies to the units they deliver. Switch on the inside, however, is a reflection of the coachbuilder.

I, for one, appreciate the two switch system, as well as the pinned switch on the face of the HWH itself.

of course, I also like fooling with the thing, and diligently empty my HWH after camping, as well as filling it with fresh each time.

Just my .02, hope this helps.

Peculiarly, our 2002 SOB Northwood Nash trailer has a 6-gallon American Standard gas-and-electric water heater. The gas end of the tank looks a lot like the Suburban SW6 series with burner, air-mixing tube, drain and Overpressure/Temperature valve all behind a louvered outside door. But the other (back) end has the electric element and switch and thermostat. There are interior switches for both the gas and electric function, but no relay is used. They simply switch the 120Vac.

[DVDim]

What I did on my W/H and a friend of mine, I extended the switch to inside the coach. The switch I used has a pilot light on it when on. You can use both gas and electric at the same time, if not already mentioned, for a faster recovery.

[dalford]

Originally Posted by Flybob

Just be sure to turn the electric portion off when breaking camp as mentioned above. If leave it on and connect to shore power without water in it, it will burn out the element quickly.

I never turn my water heater AC switch off. The only way the tank can be empty is if I drain it. I turn off the AC when I change the anode. There is always water in it after I fill it after that…

[dalford]

Originally Posted by DVDim

What I did on my W/H and a friend of mine, I extended the switch to inside the coach. The switch I used has a pilot light on it when on. You can use both gas and electric at the same time, if not already mentioned, for a faster recovery.

You can also turn the power on/off using the breaker in the breaker panel. My breaker is rated to be used as an on/off switch..