Forum Discussion

miyzfrider's avatar
miyzfrider
Explorer
Aug 12, 2013

Water Heater Control (Electric and Gas)??

On our new TT, our Suburban hot water heater is both gas and electric. Electric switch is out on the unit itself. Then we have a switch inside the TT, which I understand controls the LP function. However, what I'm not clear on is how the two interact with one another? In other words, if I pull up to a campsite, have the HWH filled with water, kick both switches on, will the LP light as well as the electric element kick on? Once the water is at temp, will the electric take over and run instead of the LP if both switches are on? Is the switch inside a "master" switch, so if I shut it off, will the electric also shut off? So in a typical camping situation, with a full HWH, should I just leave both on?

I'm just not clear how the two controls work together, or are they 100% separate from one another? The manual doesn't really say much.

Thanks!

18 Replies

  • Two separate controls.......each has their own set of t-stats
    One set for electric (120V AC) and one set for LP Gas (12V DC)
    The T-stats are mounted next to each other with High Limit on top and normal on bottom (Normal set for 130*F...High set for 180*F) Each High Limit has a 'reset button' which will trip power if high temp limit is reached (normal has failed etc.)

    Both sources for heating can be ON for faster recovery
    OR you can use just electric Or use just LP.

    I'm surprised that there is just the one electric ON switch (outside compartment)....check under sink or monitor panel for another switch.
    Thought that Suburban would have another switch by now......one switch is so old tech.

    Just make sure that water heater tank is full of water before turning on that outside compartment switch...otherwise the element will burn out quickly as in just a few minutes.
  • You didn't say what brand of trailer you have. Most higher end units have a single water heater control location (inside) with two switches. One for electric; one for propane; or both for faster heating.

    Be aware that the warning light on the propane switch only comes on when the ignition sequence FAILS. A red light means NO FIRE, which is a little counterintuitive.
  • Bobbo's avatar
    Bobbo
    Explorer III
    Think of them as the 2 lights you have at the ends of your couch. You can turn on one (40 watt representing the electric element), or the other (60 watt representing the propane burner), or both (100 watt) for more power. That is exactly how they work for heating your water.
  • Our TT only had a hot weather button inside it. Basically LP. Our Class C has two buttons inse, both 110 and the other LP. As others mentioned, if we are plugged in, we leave it on 110 and rarely have put it on LP. Maybe a few times. But then turn it right back off.

    Try it woot the LP button and see if you get hot water after a little bit. If so, then your good to go, just kick the LP on when you need it.
  • hyattjlbb wrote:
    Switch on the outside (unit itself) is more of a safety so no one can mistakenly turn it on from inside when it has no water in it (winterized). Both swicthes for LP and electric are used inside for normal operations. Like stated, use electric when you can to save your propane but turn on both for quick recovery of hot water. Once water is warm, I am not sure which one takes priority as they should both shut off once to temp.


    Thanks for all the info everyone! Our unit only has a single switch on the inside, so I assume that is only for the LP, meaning the only way to turn on or off the electric is with the switch outside (or the breaker). May have to wire a switch inside for the electric in the off season. Seems like RV manufacturers would put a switch for the electric AND LP inside. Hence my confusion.
  • Switch on the outside (unit itself) is more of a safety so no one can mistakenly turn it on from inside when it has no water in it (winterized). Both swicthes for LP and electric are used inside for normal operations. Like stated, use electric when you can to save your propane but turn on both for quick recovery of hot water. Once water is warm, I am not sure which one takes priority as they should both shut off once to temp.
  • They are independent of each other. You can run electric only (longer warm up/recovery time), LP only (faster warm up/recovery), or both (fastest warm up/recovery).

    For a lot of showers happening (spouse/kids), run both for the fastest recovery between showers.
  • Once connected to shore power shut off the LP. Save your propane!
    Make sure you trun off the 120 volt AC water heater element prior to disconnecting.