Advice on adding 110v switch for new suburban sw10de hwh?

[Tiggy]

I have a 1993 suburban 5 gallon hwh that I'm uninstalling because it's old and rusty and broken.  I want a Suburban SW10DE which has the option of 110 plus propane/12V because I plug in a lot on a construction site.

I'm puzzling over this....How do people add the switch for the 110?  The RV has one of those control panels in the stove fan with a switch which will turn on the 12v/propane HWH.  The new kind has a 110V metal box arrangement with a white, black and ground plus the usual 12v/propane setup. 

Could you put the HWH's 110 wires onto a plug, and have them plug into a switch-controlled GFCI, with 12-2 going to a new circuit breaker.  Would this work?  But what would happen if someone turned on the 12v/propane switch while it was on 110?

How is this done?

 

[MrAlvinDude]

There are two separate heating systems. And each system is regulated by its own thermostat. So if you were to activate both systems, at the same time, then the water would just heat up faster.

For some more details, of how the two thermostats work, you might want to look at the first few minutes of this video: .

 

[Tiggy]

Well thank you.  That's surprising, well but now I do recall someone saying they did something to cause faster heat-up, but I didn't know how....that is so interesting they can use both propane and electric at the same time!  I was worrying it would be disastrous.  Thank-you so much.

 

[Tiggy]

I watched the entire video and screen captured and took notes. My general conclusion is that should this HWH ever break down, just replace both solenoids, the switch, flush the tank, check for loose wires or burns/melts, that should cover 90% of the problems for under $50 in parts, and if these things don't work well then paying $130/hour for a technician is where you're at. Thanks again.
I learned that the A/C draw is 11 amps so that's valuable if I ever need to run other things.

 

[highdesertranger]

I also installed a Suburban Propane/electric water heater. I ran the 120v side to a 15amp breaker. So to turn the electric on you would turn the breaker on and the switch on the water heater. On the propane side I just installed a Suburban propane switch. Works great.

Never turn the electric on without the tank being full of water. It will ruin the element almost instantly.

BTW it's not a hot water heater(HWH). You don't heat hot water, why would you it's hot already. It's just a water heater(WH). That's how plumbers know if you know what your talking about. There use to be a member here that would harp on this, they still might be here as I don't remember who it was.

Highdesertranger

 

[bullfrog]

If you are on a construction site a lot and want more hot water available heated by grid power many people just add a residential heater that come in many sizes and are much cheaper than RV heaters. They can be installed in cabinet or with some tee's, outdoor valves using washer hoses set on a pad next to the trailer in an insulated box. It is much cheaper and easier to deal with this way than the RV style heater. There are "hot rod" heating elements that can be installed in almost any RV style heater with a drain plug that work well but you are still limited to 6 or ten gallons of hot water. An extra 10 gallons of hot water is well worth it at a job site in my opinion. That way you just insure it is full of water plug it in and forget it as everything is easy to get to or replace.

 

[Tiggy]

Thanks.  We have a little shed-cabin there with a 5 gallon electric hot water heater for the workers, but the element had to be replaced within a year, so now it's kept unplugged except for specific showers.  Bad luck I guess.  So when I come to visit/oversee, I just want my own shower.  I sold a newer RV to buy vintage because I felt terrible tearing apart a nicer RV, to make it my "own".  But this one has 1993 parts on it!  On that newer RV I had a Girard but again had bad luck, I had winterized with an air compressor but that wasn't sufficient and resulted in a copper blowout that looked like someone shot it with a .45.  So I am going back to Suburban because I can fit 10gallon in and that's enough for a fairly non-navy shower.  Can't wait to get it going! (I will winterize with antifreeze from now on, though when I previously had Suburbans I'd used a simple drain-open all valves, blowout the lines method that worked for 8 years, but that didn't work with the Girard). Thank you!

 

[Tiggy]

Along the lines of more HWH or WH bad luck; I had to return the 10 gal (NIB) that a mechanic had recommended, he said it would fit, and it would, lengthwise, but I'd have had to have cut out a whole new opening (had 6 gallon before) and still there was some structural steel under the bench which precluded that height of cutout.  So I am debating whether to get another Girard, but this time hook it up with quick disconnect water lines under the bench seat, so that come Fall I can absolutely KNOW it's blown out with compressed air right at the source, at the unit itself, because last time I used compressed air, and I guess even 1 teaspoon of water can cause a catastrophic explosion of the copper, like a huge bullet hole.  I don't want to go through that again, because Girard wasn't helpful with repairs, but I do miss the endless showers idea.

What is the sure way to Winterize a Girard assuming I'd disconnected the water right at the back of the unit?  Kind of confused here on that.  Thanks.

 

[highdesertranger]

I was wondering about the 10 gallon. I know the 10 and 12 are the same dimensions But the 6 is smaller. I figured you knew that and took it into consideration.

As far as draining pull the anode rod. What part froze can you post a picture?

Highdesertranger

 

[Tiggy]

Well you're right, this mechanic I'd hired did a quickie measurement to recommend the 10 gal. but he forgot the height!  No can do, big steel bar over the back bench seat, not cutting that!

Now that big .45 blowout was in the Girard in my former newer RV.  I was shocked, I'd had it put in and used it for a single season, then the next Fall did my usual compressed air winterization that I'd done on a previous RV with a regular Suburban hot water tank for 8 years without problem, winterizing with compressed air, all tanks emptied, all faucets left open, drained tank, pulled out anode plug.  But this time after only one season's use, I came back next season and water was just pouring out of the new Girard unit, it was broken.  I took out the unit and the beautiful copper heat exchange part of the tankless propane on the Girard had this huge bullet hole protruding outward, the thin copper just exploded outward.  :-(  Girard wouldn't help, they did sell me new copper guts, which was 1/3rd the cost of a new Girard, and this contributed to my feeling dejected about this RV (why have a nice new RV when it's got just as many problems as an old one?) so I sold that RV and got my '93 at the bottom of its value so I could re-do it RIGHT.  
There is no anode rod with a Girard.  It's really simple, has cold in - hot out and 12V power and propane connection, and a digital sensor, so I was thinking if I had 2 quick disconnect water lines, I could (for winterization) disconnect all water in and water out quickly and THEN use compressed air to truly dry it out.  Because IMO Girards are really nice but are delicate little flowers which totally fail with a teaspoon of water left in them.  That copper was really really thin.  

 

[bullfrog]

One reason to put use tee fittings and have an outside valves at the lowest points is it makes draining easier. Does your water heater have a bypass installed so you can completely drain it? If not then I would at least install one of those as well as removing the anode or drain plug. They can be purchased at most RV dealers or on line. By removing the RV water heater and using a 10 gallon water heater you can access, attached with easily installed hoses you simply remove the hoses disconnect the plug either 12 volt DC or 120 volt ac, open the drain and store it. If in freezing weather leave the valves open and blow out the lines. Granted it isn't as easy or convenient as an RV heater but much better than buying a new RV heater and installing it in the limited space most RV manufactures give you in my opinion. My sons is under the sink in his camper trailer and works great as he is usually hooked up to the grid.

 

[Tiggy]

That's a great idea having a low point drain, which this '93 19' Class C Tioga does not have.  Now would be the time for me to figure that out since I have all the upholstery out and the wood benches opened up.  It's got those old water line connectors, you know the gray plastic pipe with the brass elbows?  I was thinking I would replace a lot of that with red/blue Pex-A and a Uponor tool and fittings.
But, an interesting observation -- I was shopping for that, and was witness to hyperinflation as the Pex went up from $23 to now $78 for 100 feet in just the past month!  And 12-2 wire, 25 feet cost $36!  Supplies are scarce, too.

 

[highdesertranger]

I got all my Pex from these guys, they were the cheapest I found,

https://www.pexuniverse.com/pex-plumbing-pipe

I only paid 17 and change for 100' so it has gone up a little. I ordered just over 100 bucks worth of stuff from them so I got free shipping. I used the crimp fittings.

Also I see you mention wire. I would never use solid core wire for a mobile application.

Highdesertranger

 

[Tiggy]

That's good to know, about the wire.  I assume for 12V (strands) but are you saying strands for 110V too?  Because I was shopping the 12-2 when I had the Suburban which has a combo 12V/110V and I needed the new 110V.  In any case, prices are up, way up.
AFA the PEX I need PEX-A with Uponor for the house anyway so thought I'd put that in.  I was finding Pex-A really scarce and pricey, Pex-B not so bad.  The inspectors I hear apparently like Pex-A/Uponor because they can visually see a solid connection.  It's also "unkinkable" with a heat gun unlike Pex-B.
So I just checked your site and it's $45ish vs $89ish at Amazon for Pex-A 100' I'm going to buy that for the house build!  Thanks!
https://www.amazon.com/AquaPEX-Whit...r+"pex-a"+1/2"+100+feet&qid=1618648595&sr=8-4

 

[highdesertranger]

Yes I would not use solid wire for anything mobile. I used Ancor marine 12 gauge round triplex in my build. There is other cheaper wire out there but Ancor is top of the line.

Also keep in mind if you use stranded wire you need to use ferrules at any pinch terminals. Speaking of pinch terminals IMO they have no place in a mobile application either. But for some things they are next to impossible not to use. Also there are bad pinch terminals and not so bad pinch terminals.

Highdesertranger

 

[Tiggy]

OK thanks (looking up "ferrules")