by McDave » Thu Oct 24, 2019 10:35 pm
I have a tankless water heater and I only have the hot from the heater going to the shower. In fact, the heater came with a shower wand and 4' of hose. So if you want a cold shower just leave the ignitor switch off. There are controls for flame size and water flow that allow you to go from luke warm (low flame, hi H2o) to scalding hot (hi flame, low H2o). The wand has a on/off control. My sink backs up to the shower so I just put a tee at the heater output before the shower hose and only ran to hot valve at sink. Again, if you want cold just leave the ignitor switch off. There is also a tee there going to the toilet supply. When I winterize, Just drain fresh tank and add 2-3gals of pink RV anti freeze. Then open the shower valve till you see the pink, same for sink and toilet. Turn power off to pump. Then open the vacuum breaker thumbscrew located at the underside of the heater and open the shower control. Allow the wand to hang down. All the fluid will drain from the heater and sink line. Open the sink valve and the toilet supply and they should also drain, you will hear gurgling. To protect black /grey tanks, empty and flush out well. Then add1-2 gallons RV anti freeze down the appropriate drain and toilet. Then add just a little to the toilet bowl so the flapper seal is kept wet. If there is no liquid on top of the flapper gasses can enter there. Now all lines should be empty or have anti freeze. That's it. Easy peasy.
McDave