Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Bob & Sue on August 01, 2019, 02:52:32 pm

Title: Repurposing the "hot water dispenser" toggle switch.
Post by: Bob & Sue on August 01, 2019, 02:52:32 pm
   After switching out the waterheater electric element AGAIN cause I left it on. I believe when the water was drained.  I've decided that the the red switch under the bed isn't in an obvious enough location.

  Our water pump switch and the propane waterheater switch are in a very handy spot under the sink and directly across from the  door. So it's in direct view when coming and going from the coach. I try to not leave either one of them on if we are gone.

  The third switch in the pic is the ( now removed ) old "instant hot"  waterheater switch.  I'd like to repurpose that switch to turn on the electric (110) waterheater. That would be much handier and not out of sight and out of mind.

 Question would be what kind of relay or switching could I use to retain that OE switch. 

 Can't seem to upload the pic of said mini rocker switch.
Title: Re: Repurposing the "hot water dispenser" toggle switch.
Post by: Chuck & Jeannie on August 01, 2019, 03:47:31 pm
On our coach, when I removed the (inoperative) sink hot water dispenser, I also had the idea that the switch under the sink could be repurposed.  I originally assumed the switch turned on the instant hot water dispenser, but this was (on our coach anyway) incorrect.  The hot water dispenser did not have a "ON-OFF" switch.  It simply came on whenever it was plugged into a "hot" outlet.

What the switch under the sink actually did was "activate" the duplex outlet into which the hot water dispenser was plugged.  I never investigated far enough to figure out exactly how this was accomplished.  I assume the switch triggers a relay of some sort...but I have never seen it.  Must be hidden down below the sink floor or perhaps under one of the closet floors?

I never came up with a use for our switch, and I don't know if any of this rambling comment is helpful to you.  If your coach is the same setup, I'm thinking you might be able to modify the existing switch activated relay to control the power supply for your electric water heater element?
Title: Re: Repurposing the "hot water dispenser" toggle switch.
Post by: Travelin' Man (RIP) on August 01, 2019, 03:55:32 pm
Bob, what does your wiring diagram show?
Title: Re: Repurposing the "hot water dispenser" toggle switch.
Post by: Don & Tys on August 01, 2019, 04:51:36 pm
The newer version of the Atwood 3-way water heater, and I would guess the 2 way version with electric and gas but no motoraide, have a 12 volt relay to control the element. When I replaced our OEM 3 way, there was no switch or wiring in place to control the electric element. What I did initially was simply to wire the 12 volt LP relay hot lead together with the electric element lead. This allowed the switch on the bed platform to turn on the electric as long as the gas solenoid was energized by the switch under the counter. The new 3 way water heater came with a switch (though it didn't match the aesthetics of the Foretravel switch plates), but I hadn't run the wires yet so I didn't install it. I had previously removed the antenna booster switch, so when I got around to running the wires for the electric element control, I repurposed the antenna switch to control the heating element. Ours didn't have an instant hot water system installed, so I installed the repurposed antenna switch next to the LP water heater switch. For reasons which I don't recall, I used the original LP water heater switch to control the electric and the antenna switch to control the LP side of it. I change the red led indicator light from the antenna switch to a green one to show when it is on. I used the red led on the original LP switch for a fault indicator if the LP doesn't stay lit. The initial way of simply connecting the LP and electric element relays to the same switch worked fine, but like you, I wanted to see at a glance whether or not the electric element was on. Of course the switch on the bed still has to be on for the electric element to be energized. I just leave that on and use the switch under the kitchen counter to turn it on when we have free electricity at a camp site. I would say if you want to control the electric element with the older style of Atwood WH, the easiest way would be to add a relay where the romex cable that feeds the electric element under the water heater. Depending on how it is laid out, this might need to pull the water heater out, but perhaps your floor plan would accommodate an access port behind the water heater in the adjacent storage bay wall. You would still need to run wires up to the kitchen area and install a 12 volt relay down by the water heater designed to control at least 15 amps @120VAC (our electric element consistently draws 11 to 12 amps). Not that easy, but probably easier than running wires to the area where the bed switch is installed, and then you would already have the system wired for use with the newer version of the water heater.
The first picture is the ID plate on the then current 10 gallon 3 way water heater. Now that Dometic owns Atwood, no idea about availability.
The second picture shows the switch supplied with the Atwood unit along with the finished installation of the repurposed antenna switch.
Don
    After switching out the waterheater electric element AGAIN cause I left it on. I believe when the water was drained.  I've decided that the the red switch under the bed isn't in an obvious enough location.

  Our water pump switch and the propane waterheater switch are in a very handy spot under the sink and directly across from the  door. So it's in direct view when coming and going from the coach. I try to not leave either one of them on if we are gone.

  The third switch in the pic is the ( now removed ) old "instant hot"  waterheater switch.  I'd like to repurpose that switch to turn on the electric (110) waterheater. That would be much handier and not out of sight and out of mind.

 Question would be what kind of relay or switching could I use to retain that OE switch. 

 Can't seem to upload the pic of said mini rocker switch.
Title: Re: Repurposing the "hot water dispenser" toggle switch.
Post by: Jack Lewis on August 01, 2019, 05:37:54 pm
Don, I appreciate your detailed useful post as it helped me before updating to the new water heater.  I too was put off by the white dual control that came with the water heater.  I found this "Atwood Black Dual Panel Switch Kit" on Amazon for $15.95, wish Dometic/Atwood had provided the black one.
Amazon.com: Atwood 91270 OEM RV Dual Panel Switch Kit - Model and Unit... (https://www.amazon.com/Atwood-91270-Dual-Panel-Switch/dp/B07DS2T9LH)

It was easy to wire, requiring only 4 all in one color coded wire,18 gauge, low voltage wires, one for red error light, one ground, one to activate electric, one to activate gas, all came from the hot water heater color coded.  12volt positive wire already was there from previous switch.

Amazon.com: Atwood Mobile Products Atwood 94023 Combination Gas/Electric... (https://www.amazon.com/Atwood-Mobile-Products-94023-Heater/dp/B004SMSZFI)
Title: Re: Repurposing the "hot water dispenser" toggle switch.
Post by: Bob & Sue on August 02, 2019, 02:05:02 am
Thanks to all for the feed back.
While at Lowes today I found a lighted mini rocker switch that will handle 15 amps at 110 volts. I'm hoping that I can just run some 12/2 wire to the sink area With a return to the W heater. Could it be that simple.  ( obviously electricity is not my thing ).
Title: Re: Repurposing the "hot water dispenser" toggle switch.
Post by: Don & Tys on August 02, 2019, 02:52:19 am
That could work, though it would be a lot of work (at least in our coach) to run two 12/2 Romex cables into the kitchen from the water heater location and of course it adds considerably to the length of the run. As it is (in our coach), the romex is run from the switch which is right next to the breaker box directly to the water heater element. To switch it from the kitchen with an A/C switch, you will need a J-Box down by the water heater to extend the cable up to the kitchen, a switch box to connect the hot lead to the switch, and then a run of cable back to the water heater to connect to the electric element. With that long of a run from the circuit breaker, there will be some loss. I think it would be easier to get a relay rated to switch the current so that the run will be kept as short as possible. You then only have to run two stranded wires to control the relay.
Good luck whatever you decide to do...
Don
Thanks to all for the feed back.
While at Lowes today I found a lighted mini rocker switch that will handle 15 amps at 110 volts. I'm hoping that I can just run some 12/2 wire to the sink area With a return to the W heater. Could it be that simple.  ( obviously electricity is not my thing ).
Title: Re: Repurposing the "hot water dispenser" toggle switch.
Post by: Bob & Sue on August 02, 2019, 01:17:29 pm
Don. Again, thanks for feedback. ( quote button isn't working ).
  I get what your saying about the length of run for the 12/2 wire. I do have the "j box" in place within the water bay and the approximate amount of wire connected.  On our coach it's basically just across the coach. I figure 8' plus 6' up to the switch twice. Or about 28' probably less. 

 BUT I think I would prefer the relay route you spoke of. Less 12/2 and less power loss.  So, what kind of relay do I need.  Is it a 12 volt relay controlling a 110 connection or a 110 relay controlled by a 110/15 amp lighted mini toggle switch. That's the part of it I don't get.
Title: Re: Repurposing the "hot water dispenser" toggle switch.
Post by: Don & Tys on August 02, 2019, 02:12:12 pm
I noticed that the quote button hasn't been working on my iPad or on my iPhone for quite awhile... I am not necessarily saying this is the unit to get, but according to the specs, it would work but there are many possible sources and choices;
Amazon.com: Yeeco 30A High Current 12V Contactor Relay Switch Power Switch... (http://www.amazon.com/Yeeco-Contactor-Switching-electrical-switches/dp/B00MKWACVI)
Were I to do this, I would get a plastic project or J-box to mount the relay in, one that has knockouts for cable pass through and preferably some sort of cable clamping built in and run some 16 or 18 gauge stranded wire up to the switch location. No need for a switch box with low voltage applications. You might need or want to get some length of stranded 12 gauge wire to make the connections easier. Then make sure that the ground is maintained from the power feed to the water heater. This relay has connections for two wires in and two wires out. This is not a detailed how to, and I would most likely feel the need to do more research to insure the safety of the installation, which would possibly lead to choosing some other unit as this is just one of the first that came up in a basic search. Hope it is enough to get you started... I am sure some others will chime in.
Don

Don. Again, thanks for feedback. ( quote button isn't working ).
  I get what your saying about the length of run for the 12/2 wire. I do have the "j box" in place within the water bay and the approximate amount of wire connected.  On our coach it's basically just across the coach. I figure 8' plus 6' up to the switch twice. Or about 28' probably less. 

 BUT I think I would prefer the relay route you spoke of. Less 12/2 and less power loss.  So, what kind of relay do I need.  Is it a 12 volt relay controlling a 110 connection or a 110 relay controlled by a 110/15 amp lighted mini toggle switch. That's the part of it I don't get.
Title: Re: Repurposing the "hot water dispenser" toggle switch.
Post by: Bob & Sue on August 02, 2019, 03:17:33 pm
Thanks Don. 
That's exactly what I was trying to find in my A search.  I guess I dint know what I was asking for.  This thing should do exactly what I want. Use my ( still hot) 12 volt switch / with indicator light to activate the 110 line to the new electric element.    Cool.

 Foretravel forum gets it done again!!