EXCERPT FROM RVING FOR NEWBIES BOOK.
As most things in the RV world, “it depends”.
There are 1,2 or 3 bypass valves that need set depending on how yours was plumbed:
- Begin the process to find your water heater by-pass (assuming you don’t have one of those fancy tankless heaters), see where your water heater access panel is on outside of your RV. Most look something like this (you might not have a screen on yours), twist the “lock” on top and open the water heater. Mine looks like picture below.
- Now that you know where it is outside, go back into your RV and figure out how to access the back of the water heater from the inside.
- It could be under a bed, under a sink, behind an access panel under sink in bathroom, the list goes on and on, mine is in a convoluted place that I must be a contortionist to get to it.
- Once you have found the back end of it, there will normally be some valves known “BYPASS” valves.
- Let’s think about this, what you are attempting to do is STOP WATER GOING INTO THE WATER HEATER
- Keep in mind normally the way the valve is pointing is the way the water WILL FLOW.
- There are a few configurations, let’s look at the most common ones:
3 VALVE PICTURE (below): So, to keep water from flowing into the water heater, in picture with 3 valves, we want top valve turned so it is NOT in line with the red(hot) water line, same for bottom valve (blue/cold water line). Now what do we do with the middle one? make sure it is pointed inline, this way the water flows in the cold line, hits a closed valve on the blue line, goes up the vertical line (blue to red), hits the top and can’t go to the right since it is closed and goes to the left through the hot water line to the rest of the RV. NO WATER GOES INTO THE WATER HEATER is your objective. This picture is just a mess, it is NOT set for bypass mode and not set correctly for normal mode, it is just a mess. Do you know why?
2 VALVE PICTURE (below): Put BOTH valves in line with the water lines, so the water goes through the half circle line to the right and never goes into the water heater, this picture shows it in bypass mode.
1 VALVE PICTURE (below): The only valve on this one is at the bottom, and it points the way the water will flow, it is currently set to allow water into the water heater, turning it so the handle on it points upwards will make the water flow up the bypass and not into the tank. So how does the top part not allow the water to go into the top of the water heater? There is a check valve that only allows water to flow one way out from the top. This picture shows it in normal mode, NOT BYPASS MODE.
- So, you can see this can be confusing but if you just remember you don’t want any water going into the water heater, it should make sense.If you want to buy the book go here: https://www.lulu.com/en/us/shop/joseph-testa/rving-for-newbies-the-manual/paperback/product-9r5j42.html