If you want hot water it needs to be on.
This is the on/off switch for your water heater on propane.
If the red reset light turns on it means the dsi (direct spark ignition) did not work. So it didn’t light on propane. Make sure you’re not out.
If the water heater is also electric the on switch will probably be outside on the water heater unit itself.
Important: DO NOT FLIP THIS SWITCH UNTIL YOU KNOW HOW YOUR SYTEM WORKS.
If you flip on this switch, it will light the hot water heater. If you light the hot water heater and it is empty, it could damage it. So if you flip this switch on without filling the tank of the hot water heater, you could damage it.
Here’s the fun bit: if the RV freezes with the hot water tank full, it can burst, and you can damage it.
Here’s the even more fun bit: most RVs are plumbed with a bypass, so just because you are getting water through the hot water tap, you cannot determine if the hot water tank is empty or full.
So…
I would not touch this switch until you have looked through your RV and are confident you know what you’re doing.
Many RVs have a bypass for the water heater. The easiest way to do this is three valves and a bypass line. At the water heater, look for the input and output ports on the water heater. There should be a valve plumbed up to these ports. These are the hot water in and out valves. There will then be a T plumbed in, with a line between, and a valve on that line. That’s the bypass valve.
To use the hot water heater, you need to turn on the input and output valves, then turn off the bypass valve. Then you need to bleed the air out of the tank by running water through the hot water taps until it stops splurting. If you are on city water, I’d go ahead and run a lot of water through the tank just to rinse it out a bit. (Remember to drain your grey tank!)
To bypass it again, you need to close out the input and output valves, then open the bypass valve.
Then you need to drain the tank. There is a drain out on the outside of the RV. There’s instructions on how to do this in the hot water heater book. (There’s probably a drain plug and a safety pressure release valve that is involved.)
I would highly suggest making sure you know how to drain it before you fill it! If you let the RV freeze before you drain it, you’ll bust your heater (at least $500) and could cause water damage…
It looks like that switch turns your hot water heater on and off. I’d say turn it on whenever you want hot water. Otherwise you can leave it off.
Do you know if you have an electric hot water heater or propane, or both?
Since you are new and asking about water heaters, just wanted to make sure you knew you should never have the electric heating element (if you also have electric water heater) switched on when the hot water tank is empty, as you can quickly burn out the element, leading to an expensive repair. It’s a mistake easy to make since the electric switch is probably not illuminated, and is often on the outside of the camper by the heater unit itself.
Leave it off if you like cold showers.
If your water heater is both propane and electric, that’s the switch for the electric side of the water heater. If you’re plugged in to shore power, use this instead of propane for the water heater.
Source: New to RVs – Just to confirm – should this switch should remain off ?
