First time motorhome buyer where is the water heater bypass?

Fifty4F100 wrote:

On a related note, a plumber friend of mine says the pex lines we have can freeze about 4 times before it has a chance to burst. Has anyone else heard that?

Lines that can flex are less prone to breaking.

But it's all about pressure.
If the line is essentially open at both ends so that the freezing water can expand down the pipe unobstructed, no pressure builds up an d no pipe damage occurs......usually.

Theoretically, if you open all the valves and faucets everywhere in the system and leave them open, the water in the lines can freeze without causing damage. Theoretically.

Now the pump itself is another matter.

My manual states to somehow regulate the air to 40 psi. Most compressors have a regulator and I hope mine is correct. Before starting turn on the farthest outlet - mine being the kitchen faucet. I turn on the cold 1st. Then open the air into the system. When that stops gurgling I'm reasonably sure its mostly empty. Then open hot side and close the cold. I always leave one open as I'm not sure my 16 year old pex lines will hold the psi. I work my way back to the closest point of the outside inlet which appears to be the bathroom sink faucet. It is easy to forget a spray line in the kitchen sink and the hand held shower line. Any water can pool in a sagging area and burst. And its easy to forget to blow through the toilet valve. And yes the "P" traps need to be winterized. The shower trap is especially low and sometimes not well insulated.

Good point about the pex fittings. Some are brass these days, but most use the much cheaper plastic fittings. The pex lines won't harden too much in the cold and will stretch to allow for the expanding ice. The harder fittings might not. And all it really needs to do is stretch the metal crimp and now its not holding tight enough.

If you use (air compressor) air to winterize your rig, then you really don't need the bypass system. Simply remove the water heater drain plug, turn the compressor on (or turn on the valve), jump out of the way, and let the air blow all the water out. I do this first, put the plug back in...and last...then pour a cup of pink anti-freeze into each sink trap. Whatever is left over, I divide (as equally as possible) between the both/shower (grey water tank) and the toilet (black water tank). Has always worked for me with no problems in the spring.

Fifty4F100 wrote:

On a related note, a plumber friend of mine says the pex lines we have can freeze about 4 times before it has a chance to burst. Has anyone else heard that?

But the plastic fittings will freeze and burst sooner!

Vulcan Rider wrote:

Fifty4F100 wrote:

The bypass is in place if you wish to put antifreeze in your entire system. If you don't have or use the bypass you are using at least an extra 6 gallons of antifreeze. Not needed.

Maybe I'm missing something here but while you are pumping the pink stuff IN, if you are careful to NOT open any of the HOT faucets, at least not for very long......would that not prevent much of anything from going into the heater ??

Then drain it after everything else is charged with pink ??

At least with my coach, there's a good chance if there is a droop in the hot water line between the tank and a faucet, or the tank and the inlet outside, a hard freeze will burst the line. That's why we need to at least blow the lines out with 40 psi of air. My owners manual says it needs at least 10 gallons of antifreeze to entirely fill the lines in the system. That's got to include the hot water tank, but I have the one gate valve at the inlet and did have the check valve at the outlet side to keep antifreeze from backing into the tank. I was going to put another gate valve at the outlet last year when the check valve froze shut. Couldn't find one to fit at Lowe's. After putting it all back together, I found a box of valves on the counter at a local RV parts store. Must be an item that tends to fail over the winter season.

On a related note, a plumber friend of mine says the pex lines we have can freeze about 4 times before it has a chance to burst. Has anyone else heard that?

Dutch_12078 wrote:
The bypass valves are typically located at the back of the water heater. Check the area inside where it's located for access via a cabinet, a removable panel in a closet, removing a drawer, or possibly a removable decorative panel. Setting the valves to the bypass position is normally one of the first steps in winterizing with RV antifreeze, so none goes into the heater tank. The tank just needs to be drained.

I went looking for it, with a newbie owner friend last week and was pleasantly surprised, we found the ball valve handle inside an access door in the basement next to the tank and wasn't used to seeing a tank mounted that low. Coach is a 2005 HR Journey, if I remember correctly.

I found it. Behind the water heater. Thanks for the input.

Doug Van Dusen

Fifty4F100 wrote:

The bypass is in place if you wish to put antifreeze in your entire system. If you don't have or use the bypass you are using at least an extra 6 gallons of antifreeze. Not needed.

Maybe I'm missing something here but while you are pumping the pink stuff IN, if you are careful to NOT open any of the HOT faucets, at least not for very long......would that not prevent much of anything from going into the heater ??

Then drain it after everything else is charged with pink ??

Vulcan Rider wrote:

Fifty4F100 wrote:
Just wondering: why are you winterizing in April? Are you in South America?

I was wondering that too.

A tiny bit of plain water left in the bottom of the water heater should NOT be a problem, even if it freezes.

I'm pretty sure that mine doesn't have any kind of "bypass" and the book says to just drain it.

The bypass is in place if you wish to put antifreeze in your entire system. If you don't have or use the bypass you are using at least an extra 6 gallons of antifreeze. Not needed. Just throw the bypass and drain the hot water tank. Just remember to turn off the bypass and fill the hot water tank with water before turning it on for the 1st time! Not doing so will burn up the tank (even the electric burner if so equipped) and ruin your hot water tank. Could even start an RV fire - like one on the news this week! Not a pretty site!!!

North Carolina you should be safe unless up in the mountains. I winterized last week when I got home to WI. Have had three days below freezing since. I probably didn't need to do it but 10 buck of pink stuff was worth the peace of mind. Find your hot water heater and then look inside as close as possible to the water heater for areas behind panels or drawers and you will find the bypass. In one mine was behind a drawer in bedroom and another behind a drawer in the kitchen and another easily found under the sink. Good luck.