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Qty 2 = 10.5 Gal. Water heaters
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could someone help explain how the two 10.5 water heaters decide how to get heat?
According to my Marathon manual there is 4 ways, engine heat from driving, Wabasto, shore power or genset.
In all of the last 3 cases manual says you need to select 12v water heater in the DC panel, mine is not set yet I have hot water, Webasto has not run, although I tested it and know it works and engine is cold. I am only hooked up to 15 am shore, so does the inverter send it 120v to heat it?
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The
12v is the Webasto and the 120v will run off the gen or shore power.
When driving, your engine coolant circulates through the (2) heaters
to give you hot water. I turn the circulation valves off at the water
heaters because 200 degree water can scald you.So,
if you have hot water while plugged in to the 15 amp, your 120v
heaters are on and you can shut them off at the panel just by pushing
the button. I would never leave the water heater on unless your
actually in and using the bus. -
Tom, thanks!
So on my 02 Marathon I guess its a little different even though my owners manual describes it like you did!
I did not have a push button on the DC panel, but there is a water heater breaker in the a/c breakers below next to dishwasher, washer dryer etc. I switched that off even though I am living full time in the bus, its warm here and I am curious to see how long it keeps some hot water.
This brings up two other questions, I agree the engine heated water is really, hot, if the circ. valves are open it is always free to exchange warm water in either direction?
Second, I noticed I get a small drip, it comes from the overflow, which is a pressure relief valve, it weeps a tiny bit of water, I understand this is normal if the water gets a bit to hot or too much pressure in the tank?
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Tom are you saying if you go away from coach for the day that u turn off hot water tank at breaker panel???
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No I just meant if you’re not using the bus turn off the water heater. If for some reason the water heaters get emtpy because of a leak or something, it will burn up the heating elements.
G-Man – You don’t have a 110v button on the bottom of your 12v your panel for the water heaters like this:
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G-Man,
Are you saying your hot water heats work with JUST the 120V switch on the dash turned on? Given your hot water CAN NOT run on 12V and the manual says to turn the 12V switch on, I’m guessing it should be on. If the 12V switch is intended to indicate Webasto heating, then it sure should have been labelled differentl.
It is very unlikely the hot water heaters are wired such they can be inverter powered. That would make no sense given they can be run from the Webasto.
If your hot water is too hot, above 120-130 degrees, then you need to have that fixed before someone is scalded by the water. Some converters installed temperature controlled solenoids to prevent engine coolant to circulate in the hot water heaters above a given temperature. In the marine enviroment, in which these hot water heaters were designed, it is common to use a mixing valve on the output of the hot and cold water to prevent scalding. The marine application may not be the best for over the road engines as they run too hot, when compared to marine engines.
A small about of seepage from the P&T valve is normal at the end of a heating cycle.
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It is normal to get a little water out of the pressure relief valves when driving on a Marathon. This is because of the temperature that the engine coolant is at (180-200). The 12V heat or 12V water heat switches activate the Webasto in a Marathon. A Marathon will either have a 120V water heater switch, or it will only have the breaker in the 120V panel. As Tom stated, it is a good idea to shut off the breaker if the coach is plugged in unattended. Also if the coach is equipped with an Insta-Hot in the galley that should be turned off as well because it can be damaged if run dry.
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Tom, no 110v water heater on my 02 Marathon DC panel, looks just like your photo except mine is blank there.
I thought I had thrown the correct AC breaker to kill water heater yesterday but i still have hot water today after two showers, I just threw a few more labeled “spare” (one of the few complaints on my marathon is ac breakers dont seem to line up with labled #’s on breaker door or I am doing it wrong)…prolly one for each hot water heater.
I know Webasto is not on because I did a test the other day to fire it up and make sure it works…smoky at first but ok.
So I am wondering how my coach is powering these hot water heaters now, and how my inverters are set up.
I have inverters set to 7 amp shore power as I am hooked up to a 15 amp circuit right now. I am running one AC, one inverter has been in bulk 2 days the other float, and my techlink shows voltage in the mid 12 and 25 or so when AC running and will get up to 13/26 when no significant power load.
I am wondering if my inverters supplement my weak shore power when needed and try to charge house bank when no big ac loads…
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Only Trace 4000s can and will supplement shore power. Given you didn’t trip your 15A shore power breaker I have to believe you have Trace units.
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Gill, yes Trace 4024 sw2, mc2 version I think, and I checked firmware on the remote and reading some of BenC’s posts it looks like I have the latest update.
Gil, I am having a charging issue on my house from the alternator, there is a relay between the 50Dn alt and house bank, does the Trace inverter control this?…or have anything to do with it?
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G-man the solenoid you are referring to is there to make sure the house bank doesn’t draw down the chassis bank typically. Do you have only one alternator that supplies power to both chassis and house batteries?
It is very doubtful that the Trace controls the solenoid. Some these solenoids work based on the voltage presentpresent on the alternator side and some on both sides. There should be a small gauge wire on the solenoid going to a control board. That board or in line component will hook to the alternator side of the solenoid and possibly the the house side. When the voltage on the sense side reaches a set voltage, probably around 26V the solenoid will close. There may also be a wire running to the dash if the solenoid is also the battery boost solenoid.
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I would be surprised if G-man doesn’t have two alternators. One (usually the 50 DN) is dedicated to the house, the smaller is used for the chassis. If the coach had OTR then it is likely he would have a single alternator.
That means there is no solenoid or relay to keep one battery bank from drawing down the other. However, I think Marathon does have a solenoid or relay to merge the two banks for emergency starting purposes. If that is the case and the two have been merged it likely means one alternator could have failed and the second is carrying the entire load. Just guessing. I am not intimate with how Marathon did it.
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Hey guys, I am going to post some photos and stuff on the electrical stuff in the thread I have going there, Gil and Jon, would enjoy your comments on that!
On the hot water heaters I turned off every breaker I can find associated and I still get hot water…hmm, will call Marathon on this one!
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Hey all, any idea on how to modulate the hot water setting? Both from the engine produced hot water and when on 120v?
Little too hot now (actually WAY too hot) when its over a 100* outside! -
G-man…….I have to defer to others on this because I have a small version of a conventional house HW tank. I have no idea how to power your units, if you power one, the other or both.
I do know about how the thermostats work on my HW tank. The water, when heated from engine coolant heat exchanger get super hot and in about a month I am modifying my system to add a second thermostat to the unit to shut the flow of coolant when the water temp reaches the same setting as the electric element thermostat. My HW tank has a dedicated circuit breaker in my electrical panel and when that is off the HW tank is not heated via the electric element. I also have coolant shut off valve(s) to shut off engine coolant, but I do like that feature, just not the excessive temps. I have heard folks say to reduce the HW temps close the valves a little. All that does is delay the temperature rise so if you drive all day you still have scalding water.
I am gutting my entire water bay to do several projects such as the above to make changes I would like.
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