I get asked often what do I consider to be the my best “RV hack” that I have done to the coach. That would have to be the “Auto On” of the Aqua-Hot burner, but only when taking a shower, using a flow switch!
The idea here is we know we will need more hot water than the electric heating element can provide for showers, especially in the colder months, so this will be sure the burner is ON for us when taking a shower. If the burner is OFF, the diesel burner will not fire and we will run out of hot water quickly as electric element can’t cut it with the delta swing. (The temperature differential between the ground water in the amount of heat you need.)
So I accomplished this by using a flow switch. A flow switch is a device that detects fluid movement, in this case water, and activate the switch. It then deactivates the switch when the water stops moving. So in this case, the switch is being used to activate the diesel burner option of the Aqua-Hot as if the Burner Switch was turned ON.
You see, even in cooler weather, like it has been here in Texas, if the burner is on, we will hear it fire up now and again even though you would think the electric would be able to keep up with the needs. However as soon as you use any hot water at the sink for a short period of time, it will fire the burner when it really does not need to thus wasting fuel throughout the day.
This is not hard, but does require you to CUT the water line. As such, leeks can happen. You also need to be sure to adjust the switch so it turns on even with a slow flow as the hot water in the shower is usually not used at a high flow rate. Don’t attempt unless you understand what is involved and how it works! Most flow sensors can be adjusted for flow speed by sliding the magnetic switch forward or back on the housing.
Hope this makes sense as why we love this hack I came up with. The below video talks about how I did it.
Here is a list of different Flow Switches that may fit your need if you should choose to do this: Amazon Flow Switch Search
David, nice hack. I agree it’s a good one. Watched you for a good while. Always trying to improve something to make it better, easier, safer, etc. You remind me of ……… me. (Except don’t think I would record myself getting the shower, although it did show what point you were trying to convey)
I like the way y’all like to have fun. Now if I can just erase the shower scene.
Take care.
Great hack David! I have it on my list to do now.
Looking at the plumbing schematic, there is only 1 hot water output that is then branched off of for each faucet. We’re you able to place the flow switch on just the shower leg? I could do that with a very long wire run.
Thanks for what you do!
Love the double chuck we bought in Q btw!
Yes, I did it on the line that runs to the shower, that also feeds the washer. (same line) I did not care about the washer as Brenda always washes in cold water. The line I needed was right their above the electrical bay where my Aqua-Hot controller is. So I lucked out.
Have you noticed any reduction in flow with the switch in? Also what is the exact switch you chose?
I used this one…
http://amzn.to/2Ff1V0q
…but I bought 3 as I was not sure what I was getting into and these are china made. Feel free to buy the one that will work for you, that is why I linked to a list of them vs a certain one. :)
We did not notice any reduction in water. Seeing it is the HOT of the shower, it is normally not on all the way as it is.
Dave, super idea and I agree that Tiffin should include this in the build process of a coach.
BTW, is this electrical connection 12V or 115-120V? I’m not much of an RV electrician.
Not really any voltage as it is used as a signal wire. “If this is ON then do this”. So it does not carry any voltage so to speak.
In this case, if not sure what you are getting into, then I might advise against even though it seems simple enough. You need to understand how the system works and thus how to adjust the flow meter so it will work. More or less, you need to move the switch part forward or back on the housing depending on the flow. After all, it may work just fine if you turn it on all the way, but when you slow it down, it need to be sure it does not turn off.
Hi David,
I like your hack for the water flow switch! Do you know if the switch can be wired into a 2015 Allegro Bus as the Aqua-Hot controls are integrated into the Spyder Controls. I can see adding the switch to the Aqua-Hot board, just not sure if it affects the Spyder Control system?
Hi…If it has the control board you see in the photo, I would not see why it would not work. BEFORE DOING THIS…BE SURE YOU HAVE THE SYSTEM TYPE CONTROLLER! You can tell by taking the cover off and using a paper clip short pins 1 and 2 and the Aqua-Hot should activate.