How does the Gas/Electric Water Heater Work?

[syoun10]

My (new to me) 2005 Everest has a water heater with no visible markings on it (presumably because of the insulation covering it) but the Everest came with a manual for a Suburban heater model SW12D, SW12DE or SW12DEM, so I presume it's one of them.

The manual is VERY skimpy, but it says that if the heater has the electric option, there is a switch by the heater to turn it on. I can find no such switch, but I presume it does have the electric option as there is a breaker marked "water heater" in the elec. box, and a wire going to it.

So my question is - how do the gas and elec. controls interact? Do they both come on together when the thermostat says heat is needed? Or does it have separate thermostats with the elec providing the heating to maintain the temp during periods of no water usage, and gas providing the "quick" heat the get the temp back when hot water is used? This latter would seem to be the strategy that makes most sense, but I notice the red light by the gas on/off switch coming on periodically for a few seconds even when not hot water has been recently run.

Maybe I simply haven't yet found the elec. on/off switch that the manual references, in which case where will I find it? For obvious reasons, I'd much rather use elec. as much as possible if it's equipped to do so.

[Campy]

The "combo" water heaters I have owned in the past had a separate switch outside in the waterheater door to turn on the electric part. The gas portion is controlled by an inside switch on the panel with your monitor switches. I always used it on gas and when the system needed a boost I would run the gas and electric both.

[syoun10]

Thanks, Campy. for your quick reply. Just for my info, why would your preferred mode be "gas only".

Since I don't pay for elec. when camping, mine would be to use as little gas as possibly. Not just because of the cost (which is not that big a deal) but because it's a pain in the neck to take out the propane tank and take it to be filled.

[syoun10]

Following Campy's post, I checked in the outside compartment and - yes - there is an unmarked switch there. It was set to "off" and I changed it to "on". Inside the compartment there are several warning stickers about propane, but no mention of electrical heating at all. But I have to guess that the switch is it.

Still interested, though, about the way gas and elec. interact, as per my original post in this thread.

[JRTJH]

In case you didn't notice, the electric switch is installed "upside down" with off being on the top and on being on the bottom. I've got no idea why Suburban does that... Or why they "hide" the switch in the location they do.

Anyway, as with any electric water heater, the recovery rate is slower than with gas. So, in actual use, if you're going to use only small amounts of hot water at intermittent times, the electric element will usually be sufficient for your needs and you wouldn't gain anything by using propane. With a 12 gallon water heater, you may even get a "quick shower" without having to use propane.

On the other hand, if you're a "large amount of hot water" user, the propane heating function will offer a much quicker "recovery time" and provide for a greater amount of hot water.

I have found (as have most campers) that during the day, the electric system is all that's necessary, and in the evenings, when taking showers, just turn on the propane side to "supplement the electric element" and turn it off again when showering is done...

The water heater is designed to function on electric, gas or both without any problem. You won't hurt anything (as long as there's water in the tank) by using either (or both) energy source.

[chuckster57]

FWIW, I run both.

[bobbecky]

When you see the recovery ratings for these units, it is with both gas and electric working. There are two thermostats, one 12 volts that controls the gas function, and one 120 volts that controls the electric side. Also, with the Suburban, there is an anode that should be replaced regularly, usually once a year with normal use, and this is used to protect the steel tank from early failure.

[Ken / Claudia]

Lets hope were was a full load of water in the tank when the switch was turned on. That's why I as a non full timer stick to propane. It uses hardy any propane. And I won't leave the outside electric switch on due to forgetting about it burning it out.

[bdaniel]

I usually run only electric when at a campground but sometimes run both when I want hot water "now".

Putting the switch outside on the hot water heater is stupid, especially on a unit with 30 amp service. Running microwave, A/C unit and hot water heater at the same time is going to pop the 30 amp breaker. And we often overnight with just our Honda EU3000 which puts out less than 30 amps. So power management is a must.

I have always installed a switch inside the RV so I can control the 120V heating element from inside.

http://bobbystuff.com/rv/188/water-heater-switch
http://bobbystuff.com/rv/30/switch-for-hot-water-electric-heating-element

Bobby

[canesfan]

Lets hope were was a full load of water in the tank when the switch was turned on. That's why I as a non full timer stick to propane. It uses hardy any propane. And I won't leave the outside electric switch on due to forgetting about it burning it out.

This bears repeating. ALWAYS make sure the hot water heater is full before you turn on the electric switch, and remember to turn it off BEFORE you drain the hot water heater.

FWIW when I'm in a CG with hookups I leave it on electric. I always have hot water when I get up in the morning without having to remember to turn it on and heat up before I take a shower. If I'm dry camping I'll turn it on in the morning to take a shower, and turn it off when I'm done. It will usually stay warm all day if it's not too cold. To each his own though, either way works.

[bdaniel]

I forgot to ditto the remark about not turning the electric element on when the tank is empty. The regular short heating element from Lowes or Home Depot will work fine as a replacement if you do that. Don't think you have to get it from the dealer.

Don't ask me how I know that. :-)

[concours]

Just as a side note if you do have to change the heating element you will need a 1.5 inch element socket as a regular socket will not fit thru the tin shield also the thermostat may also be tripped ot failed as a result of the element failure to change the element and thermostat is only a $25 repair on big deal. the socket can be purchased from lowes home depot etc.

[chuckster57]

Just as a side note if you do have to change the heating element you will need a 1.5 inch element socket as a regular socket will not fit thru the tin shield also the thermostat may also be tripped ot failed as a result of the element failure to change the element and thermostat is only a $25 repair on big deal. the socket can be purchased from lowes home depot etc.



I bought a 3/4 drive 1 1/2" socket from AutoZone and it fits.

[Jgkopp]

What do you guys think of draining the w/h by pulling the anode rod when the rig sits for a while? Does not freeze in our area. I never really did a domestic water system drain after a long sit. I just make sure I run plenty of water through the faucets to flush out any stale water.

[syoun10]

Thanks all.

I'm the original poster of this thread. Thanks for advice & info.

I switched the elec on, and am still getting hot water. I probably won't notice the difference except slightly lower gas usage.

However since we're full-timing over winter I now know to be cautious of electric space heaters, plus the water heater, pulling to much current and tripping the breaker (hadn't thought of that before - could happen in the middle of the night - what a pain!)

[Campy]

My new camper in my sig does not have the gas/elec option only gas and that works just fine for us. The recovery rate on gas is so fast we just turn it on as needed and it's mostly off during the day. As mentioned above about pulling the anode to drain, I have found that if my camper sets more than a month with no use the water in the heater turns black and stinks so I drain it often by pulling the anode. Make sure to keep spares around as they "go away" quite quickly. Also do NOT use anything but a true Suburban anodes because the aftermarket one are made of a material that does not corrode away like it should so i'm betting it's not doing a proper job!

[Alpine]

How about another thought for this thread... We use our electric about 99.8% of the time, the other .2% is when I fire up the propane side just to keep things working properly. I have convinced myself that some problems occur because mechanical items sit too long without use. When stationary for long periods of time, I even bring "in" the slides and "up" the auto-level system! :D

[JRTJH]

My new camper in my sig does not have the gas/elec option only gas and that works just fine for us. ...

If the "new camper" you're referring to is the 2014 Cougar 327 RES, the Suburban gas/electric water heater is standard equipment. There is no optional water heater. If you open the outside access door and look under the gas line in the lower left corner, behind the air mixer you'll find a switch, probably with a "safety pin" in the bottom half. Remove that safety pin, push the bottom part of the switch in and it will turn on the electric heating element.

There also is a 15 amp circuit breaker in your main electrical distribution panel labeled "Water Heater". It also must be turned on.

There is no other "standard build/optional build" water heater in the 2014 Cougar line.

The inside will look similar to this picture. you'll find the switch as indicated. If you're not familiar with the switch location, it can be daunting to find it. I've known many people who "swear it's not there" and when I open the panel and point to it, they simply can't believe what they see....

Good Luck.

[notanlines]

What John said^^^^^^. The Cougar three spaces from us has the same water heater and he claims they pretty much all come that way, at least on the bigger ones.

[canesfan]

Adding to what John said ^^^, I guess Keystone thought the little "safety pin" was costing too much, my current rig came with a piece of tape over the switch instead. :rolleyes: If I didn't know the switch was there I probably would not have removed the tape to find it. $50K RV and they skimp on a 5¢ part. :banghead:

[JRTJH]

Adding to what John said ^^^, I guess Keystone thought the little "safety pin" was costing too much, my current rig came with a piece of tape over the switch instead. :rolleyes: If I didn't know the switch was there I probably would not have removed the tape to find it. $50K RV and they skimp on a 5¢ part. :banghead:

I completely agree with you, but wonder if it's a five cent part or a penny part ??? It's for sure a "CHEAP PART" !!!

I'd wonder if we can blame Keystone or if it's Suburban who is "squeezing the penny" on this one. Pretty much all Keystone (and other RV manufacturers) do is order the "standard components" from the individual suppliers. What gets delivered is what the manufacturer is producing (in China or in the US). I can't imagine Keystone specifying a switch without the safety pin. That would mean "special orders for Keystone parts" and probably would increase the price per unit. My bet is that it's Suburban that's the "cheap guy" on this one.....

[DNKCowboyFan]

I think that whether you run with propane or electric is a personal preference, and you probably can experiment and see what works best for you. I would echo the posts regarding the dangers of having the electric on, and not having the tank filled with water. If you turn it on, be sure the tank is filled with water by running the hot water faucets inside until water runs through. I always run mine on propane only for a couple reasons. One, I don't want to run the risk of having it on with no water in it as mentioned. But mainly, I like to be able to control when he the heater is on and when it isn't with the switch inside. If the electric is on, and you switch off the inside control panel, it will only turn off propane and will keep heating with the electric. These tanks heat water so fast, that I often turn mine off at night, or when gone for long periods, then turn it back on when I need it.

[Bohdan]

Greetings Folks,
I have a new to me, 2010 Fuzion Limited Edition 2. Suburban SW12DE Water Heater. I see the electric switch in the corner. In addition, there is a water heater switch with a red "reset" light next to it right above the toilet in the inside. The light stays on for about 5 seconds then goes out. When the light inside is turned on, the propane kicks in and doesn't go off. If the outside switch is put on by itself, does this only triggers the element? What about thermostat? Mighty obliged.

[Logan X]

Greetings Folks,
I have a new to me, 2010 Fuzion Limited Edition 2. Suburban SW12DE Water Heater. I see the electric switch in the corner. In addition, there is a water heater switch with a red "reset" light next to it right above the toilet in the inside. The light stays on for about 5 seconds then goes out. When the light inside is turned on, the propane kicks in and doesn't go off. If the outside switch is put on by itself, does this only triggers the element? What about thermostat? Mighty obliged.

The link below is for a thread from earlier today. I think it may help answer your question.

http://www.keystoneforums.com/forums/showthread.php?t=38201

The switch with the red light is for the propane heating and the other switch is for electric heating. They can be used together or individually. Is used together they heat the water faster.

Edit-make sure the water heater has water in it when you turn on the electric side. If there is no water the heating element will quickly fail.