April 20, 2022

TT# 131 A Hot Shower Immediately – Without Wasting Water!

By: Rob Lowe

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A Hot Shower Immediately – Without Wasting Water!


How would you like to turn on the shower tap and within a second or two have hot water? How about eliminating water being wasted, thereby increasing your RV’s water capacity? If your coach has an Aquahot (or Oasis) heating system, then you already enjoy a hot shower immediately. Newer coaches equipped with a Truma or competitive brand of instant hot water heater offer the almost immediate hot shower benefit. This TechTip will focus on an invention, which uses simple technology to offer instant hot water at the showerhead on RVs that have a 6- or 10-gallon, conventional water heater. Many newer RVs have their water heater located near the kitchen or a bathroom, however it is common on older RVs to find the water heater a lengthy distance away from the shower stall. The Showermiser offers an innovative approach to water heating that is being offered on many new RVs. Without much effort it can be retrofitted to almost any RV, and this TechTip will cover the basics of doing the installation.


ShowermiserThe Showermi$er technology is simple: When hot water passes through the blue plastic fitting, it turns white when the water is hot. By using a heat sensitive, color changing fitting and a simple valve, the incoming water can be directed to the freshwater tank until it is hot. All incoming water that is cold, cool, or warm is returned to the freshwater tank where it can be used for any purpose. As the incoming water rises in temperature the special fitting (an Elbow or Straight Pipe) changes from a bright blue color to a lighter blue, then almost white. At that point, the newly added water valve is flipped to send the hot water to the shower head, rather than back to the freshwater tank. Note that none of the unused water ends up in the grey tank until one uses the hot shower water while showering.


Back of ShowerIn the following installation, access to the shower water control valve was gained by removing a panel in the adjoining bedroom. On some RVs, a mirror or other nearby panel will need to be removed to gain access to the fittings behind the wall. Behind the shower you will find the hot (red) and the cold (blue) plastic tubing connected to the shower valve. Once the mounting area is confirmed and the location of the diverter valve is established then a single hole is drilled through the shower enclosure which will allow the return to the water tank water fitting to be inserted through the enclosure (white arrow) and tubing connected. This pipe will be directed to the area where it can be connected to the freshwater tank.


New Access Hole for PipeOn this RV, the return (white) tubing was run behind the shower stall, down the wall and through a new hole in the floor (near the water piping access hole), then across the RV to the outdoor shower compartment where the water distribution valve was located. This is the valve often mounted to the outward facing vertical panel in this compartment that allows the RVer to select the water source. It usually is labelled ‘Fresh Water Tank’ in one position and the ‘City Water’ in the other position. Looking at the valve behind the panel, one will see the piping going to the water tank and to the external campground source. The new tubing is connected by means of a proper sized tee to the tubing going to the water tank. If there is a restrictor or in-line water flow control fitting, then connect on the water tank side of that fitting.  

Water Pipe routeThe Showermi$er fittings are assembled and attached to the existing shower valve and then fitted through a suitable drilled hole in the shower wall, as shown in the photos.


RV Water Selection ValveShowermiser installedWhen the new valve is in the ‘water flow to the tank’ position and the hot water valve is on, the warming water flows back to the water tank. As it becomes warmer, the blue fitting becomes white. At this point, the new valve is turned to the ‘Shower’ position and hot water flows through the showerhead.  Finally, a hot shower and no fresh water is wasted!


There is an additional benefit gained from installing the Showermi$er: This same valve can be used to fill the RV water tank, when connected to City water, if that ability is not available with the RV. Turn on the City Water and run the shower in the ‘bypass the shower’ mode and the incoming water will flow into the water tank, adding water to the tank. Of course, one must monitor the water level, as the tank is being filled to avoid overfilling.

Hot Water!Note: When waiting for hot water to shower on City Water, there must be space in the tank for the overflow, if using to avoid overfilling.


If you like this add-on accessory and want the same benefit in the kitchen, Aqua View Inc., offers a Sinkmi$er version. Check out https://aquaviewinc.com/product-tag/showermiser for information. 


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