Understanding hot water

[jmcelvoy]

We just upgraded from a Pop-up to a Travel Trailer and I'm not sure how the hot water heater works. We never used it on the PUP. I'm reading there is a bypass on the TT that I'll need to turn off/on in order to fill up the hot water tank, but not 100% sure on how/where that is. My understanding is we need to fill up the hot water tank before turning on the heater. Our TT has propane or electric heater, and someone suggested bleading the blow-off valve before using the electric heater before using, but that doesn't make sense to me. Can someone give me a quick run-down of how this all works or link me to an explanation? I've watched some videos and read some articles but not finding a start to finish explanation. We have a 2019 Starcraft Autumn Ridge 26BHS.

[myredracer]

After hooking up to city water (after de-winterizing & all season long), I always open hot & cold faucets until they stop spitting & hissing air and there's a steady flow of water coming out, then the heater gets turned on. We never use the water heater on electric and have it turned off at the heater so it will never accidentally get turned on if the tank is dry. If the tank was empty, it takes a bit to fill up and you can hear it filling up (at least I can) and while it's filling, you'll only get air out of the faucets.

If you have a 30 amp TT, the electric element will take up about 1/2 of your available power. Unless you are wanting to make a CG pay to heat your water or need to conserve propane, run it on propane. It's much faster anyway. Electric and propane can be used together if you want faster recovery. An electric element will burn out in seconds without water in the tank.

One thing not to do is to open the pressure relief valve after the heater has been turned on to avoid getting scalded.

Did the dealer not demonstrate how to winterize & de-winterize? When the time comes this fall, you can winterize with either compressed air or RV anti-freeze. Another thing to know is that there's two types of anti-freeze and the propylene glycol type is a much better choice. Also, there's "low point" drains underneath to drain water out of the lines. At the end of each season, you should inspect the anode rod for erosion and replace when de-winterizing if needed. Keep a spare on hand.

BTW, remember to turn the heater off while parked at home so you're not wasting propane or possibly using it up.

I discovered by accident while in Las Vegas (forgot to turn heater on) that you don't even need a water heater... Cool! :C

[happy2rv]

All of this probably seems really confusing. Most water heaters do have bypass valves that are commonly used for winterizing. Many water heaters are installed in locations that make them hard or impossible to get to as they are usually on the back side of the water heater. Mine can theoretically be reached by pulling drawers out of a dresser and contorting yourself while stretching beyond the limits of human arm length. Many people, including me, never use them. Also, many (most) RVs don't come with plumbing diagrams and many don't really provide any help with locating valves, tanks, etc.

So you may or may not need to find these bypass valves. What others have said regarding operating the heater with an empty tank is very important though. Nothing good comes from operating the water heater with an empty tank. In propane mode, it MAY not hurt anything, but in electric mode, as others have already suggested, it will quickly burn out the heating element.

So how do you verify the tank is full of water? This is where someone was suggesting to you to use the over pressure (OTP) valve. If the water system is under pressure, either from the "city water" inlet or water in the tank with the water pump on, and you pull the manual release on the over pressure valve, it will allow you determine if the tank is full. While the tank is filling with water, you should feel and hear air coming out of the opened valve. Once the tank is full or near full, water should start to flow from it. If the water has been on for a while and you don't see/hear air and water from the OTP valve when its open, then your heater has likely been bypassed and you will need to find the bypass valves to restore water flow.

Once you've verified that the tank is full, then turn on the heater and verify that it is heating as expected. You can run it in electric only, propane only, or both.

[coolmom42]

The bypass valves are so you do not have to fill the water heater with RV antifreeze when you winterize. All that does is move the valves so the antifreeze goes through a line between the water heater inlet and outlet, instead of through the water heater. The water heater should be drained for winterizing, with no antifreeze in it.

To use the water heater, you should turn the bypass valves so that the cold water goes into the water heater, fills it, and goes out the water heater. DO NOT turn on the water heater until you are sure it is full of water.

[mobeewan]

roadrat2 wrote:
You bought from a dealer, correct(2019)? They should demonstrate all of the systems for you.

If there's water in your fresh water tank, run the hot faucet until water comes out. If you get water, the valve is open, there's water in the heater, so you can turn it on. If you get no water, you need to open the supply valve for the water heater. This valve should be downstream from the water pump...most likely after a 'T' in the supply line. Once you find and open the valve run the hot faucet again...

There should also be a manufacturers diagram of the fresh water system, showing which position all valves should be in, for regular use as well as water heater bypass(for winerization). Good luck.

WRONG!!!

The bypass valves diverts the cold water line back through the hot water line. The bypass valve allows antifreeze to flow from the cold water line back through the hot water lines without filling the water heater with antifreeze when you winterize. With the water heater bypassed you will still get water cold water coming out of the hot water side of the faucets. The water heater can still be empty.

[Old-Biscuit]

Look at the backside of water heater (from inside the RV)

Need to OPEN cold water inlet to WH Tank (bottom valve)
Need to CLOSE 'bypass valve' (on line that connects cold inlet with hot outlet)
Hot outlet....might have a valve that needs to be OPEN but more likely no shutoff valve but a check valve that will OPEN when water flows out of WH Tank


Water Heater Tank will take a while to fill ----6 gal/10 gal

Post BRAND/MODEL of water heater for SPECIFIC info


On Edit: Looking at photos you have an Atwood
S/B a dual on/off switch with RED light between switches
Left side for electric element (need 120V AC Power and 12V DC)
Right side for propane (need propane AND 12V DC)

12V DC used for control power for both electric and propane
Electric element and DC Relay on backside of WH Tank
Propane is DSI (electronic spark)

T-stat is pre-set to OPEN at 140*F and CLOSES at 110*F (to heat/reheat water)
ECO (Energy Cut Off/HI temp t-stat) OPENS at 180*F and triggers RED FAULT Light on switch panel
*ECO will CLOSE when water temp drops below 150*F BUT FAULT Light/Control circuit has to be reset by turning switch OFF--wait 30 seconds--turn back ON

If propane fails to light off and prove it lit....circuit board makes 3 attempts then 'locks out'----triggers RED Fault Light (same reset procedure)
**common issue when FIRST using RV after propane has been valved out

[bobndot]

See the pics in this thread , that shows the valves for bypassing the WH to winterize it or summarize it. Read the entire post for WH info.
Best of luck with your new TT .
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/29649491/srt/pa/pging/1/page/2.cfm

[BB_TX]

Many RVs have a single water heater bypass switch, sometimes some where near the water connections. You turn it to BYPASS to route water around the WH, or to NORMAL to route water thru the WH. Turn it to normal, open a hot water faucet, wait until you get good water flow (meaning no air being pushed out), and then you can turn on the water heater.

Some RVs have one, two, or three valves on the back side of the water heater. These valves are turned one way to bypass the WH or anther way to run water thru the WH. You need to make sure water is going thru the WH before turning it on. The link below shows different valve arrangements. Find the one that matches yours. The link shows how to configure the valves to bypass the WH for winterizing, so you would need to turn them the opposite for normal use.

Water heater info

[turbojimmy]

wnjj wrote:
If you get water from the hot faucet, it does not guarantee there’s water in the water heater. If it’s bypassed, you’ll just get cold water.

Yes - that's the way mine works. It has 2 valves on it. One shuts off the fill for the tank and the other bypasses the tank outlet. If the latter is in the bypass position I'll still get cold water out of the hot side.

On mine the only sure way to tell if there's water in the tank is to open the drain on the outside.

YMMV

[wnjj]

roadrat2 wrote:
If there's water in your fresh water tank, run the hot faucet until water comes out. If you get water, the valve is open, there's water in the heater, so you can turn it on. If you get no water, you need to open the supply valve for the water heater. This valve should be downstream from the water pump...most likely after a 'T' in the supply line. Once you find and open the valve run the hot faucet again...

If you get water from the hot faucet, it does not guarantee there’s water in the water heater. If it’s bypassed, you’ll just get cold water.

You have to be sure the valves are not set in bypass mode and/or pull on the relief valve to see if you get any water out when the system is pressurized.

[midnightsadie]

never ever turn the electric heater on till your sure theres water in the tank, it will burn up the heating electric element.

[pianotuna]

1 fill the tank with water
2 turn on the electric
3 wait 90 minutes.

For quicker heating use both the propane and electric settings.

The water may be much hotter than in a home, so use caution when adjusting the temperature of the shower.

[roadrat2]

You bought from a dealer, correct(2019)? They should demonstrate all of the systems for you.

If there's water in your fresh water tank, run the hot faucet until water comes out. If you get water, the valve is open, there's water in the heater, so you can turn it on. If you get no water, you need to open the supply valve for the water heater. This valve should be downstream from the water pump...most likely after a 'T' in the supply line. Once you find and open the valve run the hot faucet again...

There should also be a manufacturers diagram of the fresh water system, showing which position all valves should be in, for regular use as well as water heater bypass(for winerization). Good luck.