Gas or Electric or Both?

[Axion]

I have some questions about the water heater in my RV.



It is a 10 gallon unit made by Suburban (SW10DE) and can run on gas or electric. This fall I found that when used on electric, the water never got hot, just kinda warm. Now that the cold weather has hit I seem to be going through a bunch of propane with both the furnace and water heater burning gas.



Is it possible to use both gas and electric on these units at the same time or is it a "one or the other" kind of situation? If I don't replace the element and use it as a kind of pre-heater, with the propane making up the difference, will there be any adverse affects? Or should I just suck it up and replace the element and use the electricity I don't pay for to keep the water hot?



Lastly, is a new element expensive and are they difficult to change out?

 

[MChildress]

Your element is probably scaled up or gone. I would replace it especially if your not having to pay for the additional electricity. The gas will heat the tank up faster and most when running on elec will automatically switch to gas also when a heavy demand is required like tanking a shower.

 

[Skydiver]

Axion, sounds like your element has failed. A simple ohms test will determine. On my old camper I could tell the electrical portion of the water heater was working because the ceiling lights would dim slightly when it energized.
Your water heater should have (not sure) two thermostats. One for elec and one for gas. If the gas thermostat is adjusted for a slightly lower heat setting, the gas burner should fire only when the hot water demand increases thus saving gas.
With both power supplies and water off remove the drain plug on the bottom of your water heater. This is a simple job, but you need to make sure to use the properly sized wrench so to not strip the plug head. After the water has drained turn on the water supply. This will flush sediments such as calcium from the base of the tank. While the tank is empty might as well replace the electrical element. Be sure to refill and purge the air from tank before turning on either energy source. Operating it dry is the fastest way to destroy your water heater.
I only turn off my electrical element when plugged into a house type receptical such as when at hunting camp with limited current. When plugged into a 30 amp circuit both sources of energy remain on.
Good camping tips. (LONG) Poop Sheets by phred

 

[ScottLewis]

When you have the drain plug out, use a slim tube on the end of a water hose to flush out the tank. Lots of minerals and crud accumulate in the tank.

 

[DavidC]

I usually run mine on both electric and gas at the same time, mainly when it's shower or doing the dishes. Then I turn the gas off during other times so the water does not cool off to much and I have to reheat the whole thing again.



Dave

 

[Axion]

Well, looks like I'll be putting in a new element and running both heat sources.



And, WOW, anyone that wants an education in RV's should check out the poop sheets by phred that Skydiver linked to a couple of posts above! Looks like I've got some reading material for the next while.



Thanks to all for help and advise.

 

[ChrisOlson]

This is some great stuff on the Poop Sheets

 

[jelag]

A water heater element usually fails and goes to an open circuit and there is no heating of the water... . but the element is usually under $20 and is a simple change...

I'd flush the system, check for poor connections, replace the sacrificial anode as well as the heating element...

When the snow flies here, we pull the plug (sacrificial anode) and drain it... I'm guessing we don't see 3 years on the anode... if you've not looked at it, and its gone that might be a good cause for the heating element failure...

 

[richardcoxid]

The gas/electric thermostats previously mentioned are normally NON adjustable “snap stats”. They are about ½ inch in Dia and ½ inch high with two push connector terminals on one side and “ears” for mounting. For RV HWH application they are normally held against the tank by a black piece of foam tape. The gas stat will be on the gas side of the heater and the elect stat on the electric heating element side.



As a point of interest- Remove the gas side stat. take it to your local wholesale electrical store (I don’t think that Home Depot, Lowes stocks them). By cross referencing the part #’s, purchase (low $ item) a stat that turns “on” at a 10* lower temp. You want the electric stat to come "on" before the gas stat. That way when connected to shore power normal heat loses will be made up by the electric only and when you use a larger quantity of hot water the electric stat will come on first, if the electric can’t maintain the temperature then the gas will come on to maintain temp. Both being “on” at the same time will save your propane!



Remember to de-energize ALL electrical power when working on the HWH.

 

[Axion]

Went out over the weekend and picked up a new 1440W element. It was $35 CDN at my local RV dealer. I checked online and the prices were pretty similar once you factored in shipping.



I was draining the tank and using a small plastic wand with a bent tip to rinse it out for the first couple of years when the RV was put away for the winter. When I'm in the unit full time, I rinse things out after two or three months. It is amazing how much scale comes out after a short time. Too bad there isn't a better way to flush these tanks out. I have replaced the anode rod twice and keep a spare on hand.



I will look into changing out the stats. It makes good sense to have the electric come on a bit sooner. It may have to wait till spring though.



I'll check back in once I've swapped the elements.

 

[richardcoxid]

Axion



Maybe I sdould of added to pull both thermostats and check to set points of both.



Richard

 

[Radshooter]

If you haven't done this yet, this is a good time to replace the anode while you have it out.

I don't remember what size socket I used on the heater element, but it was bigger than anything I had, so I had an excuse to buy a new, bigger socket set!!

The new sockets were not thinwall, so I had to Dremel the access hole just a bit to get clearance for my socket. Be careful where the sparks fly.

Not near as complicated as I thought it would be. The hardest part for me was getting the gas tube re-installed after I removed it for clearance.

 

[Grizzly]

If you haven't done this yet, this is a good time to replace the anode while you have it out.



I don't remember what size socket I used on the heater element, but it was bigger than anything I had, so I had an excuse to buy a new, bigger socket set!!



The new sockets were not thinwall, so I had to Dremel the access hole just a bit to get clearance for my socket. Be careful where the sparks fly.



Not near as complicated as I thought it would be. The hardest part for me was getting the gas tube re-installed after I removed it for clearance.

The socket size is 1-1/16".



george

 

[jelag]

I bought an inexpensive ratchet, and a socket like George mentions and leave it in the trailer and when I pull the plug, the anode and the tool sets under the cover(water heater) with the cover propped open until its back together... .

The open door and anode plug is the last part I put back together in the spring... . so the water system is ready to be charged...

 

[JRBurton]

I'll just put my 2 cents worth in. I am on my second self contained rv and both have had the exact same situation as you have described. both units were purchased new and the electric never got the water hot, just warm. I just used the electric as sort of a pre-heater and relied on LP to get the water to the temp that I like.



John

 

[HBarlow]

I'm surprised by several reports here. I've owned several trailers with combination electric and LPG water heaters. All have provided extremely hot water using the electric element. I never use the LPG water heater element in my HitchHiker if shore power electricity is available or if I'm running my Onan generator.

 

[AClayton]

I'm surprised by several reports here. I've owned several trailers with combination electric and LPG water heaters. All have provided extremely hot water using the electric element. I never use the LPG water heater element in my HitchHiker if shore power electricity is available or if I'm running my Onan generator.

You know... ..... I was thinking the exact same thing! Nearly everyone in the RV Club that I belonged to used electric only. Since I bought my new toyhauler in May, the gas has never even been used. I rarely use gas and the ONLY time I have ever even used it at all was when multiple showers were taken. I have always had good luck with electric and with the money that Campgrounds require for overnight stay, I use electric HW.



But on an unrelated note - It really bothers me that campers leave their doors open with the A/C on. The excuse is... ..... why worry about it, we pay for the electric!





Alan

 

[HBarlow]

Me too. It's the same thinking that makes public housing provided by taxpayers a sad mistake. Some people think it's okay to waste everything when someone else is paying.

 

[jelag]

The part I don't care for on my 12 gallon water heater is I've got to go outside, open the cover, and turn on/off the electric switch... . and its got a clevis pin through the switch to lock it in the off position... . I guess so it won't run when your plugged in and put away for the winter... .

But like I mentioned above... . they usually heat correctly and give good hot water... . or their open circuited and no hot water... . something in between isn't in the cards for most electrical circuits...

 

[HBarlow]

Really? I've never seen an RV water heater with the switch outside. Why don't you install a switch inside like over the kitchen counter and route the wires down through an under counter cabinet to the water heater?