Water Heater - No water

DooDahDay · 06-10-2021, 05:55 PM

Hi All - I don't get around to posting very often but I definitely stalk pretty regularly.
Heading out for an impromptu boondocking weekend and had not de-winterized*yet. Yesterday my wife started prepping and for some reason ignited the water heater. I step into the trailer today and noticed the w.h. gas switch on the panel was lit - one of those heart dropping moments because I realized it must have been on all night. Went around to the other side of the trailer and noted sooty stains on w.h. grill and above. Not good. So I got all of the de-winterization tasks completed and filled the water heater. No leaks. But, it will not ignite when I flip the gas switch on. Since we're boondocking, I really don't even want to know right now if the elec doesn't work. We are fine with bucket showers for 2 nights.
Typically when flipping the w.h. gas switch, I hear the igniter clicking and then the whoosh. No clicking, no whoosh. Gas supply*seems ok - I checked the stove.
Any thoughts on the level of*damage done? Hoping it's going to be the igniter panel, if there is such a thing, but the signs of WAY too much heat coming from the w.h.'s vent is bothersome. Appreciate any insight on this... as we all know, this is absolutely, 100% my fault.

sturgissteele · 06-11-2021, 07:20 PM

You shouldn't have any soot if it's working properly. Check the pipe where the gas is mixed with the air. Sometimes a spider or other insect will take up residence there and mess up the air fuel mixture. Pull it out, (notice how it was positioned) and clean. It might not lite off if the pipe is clogged.

DooDahDay · 06-15-2021, 11:15 AM

Thanks for the head's up John. Cleared that pipe, although it was clean. Still the igniter will not engage (click). The Electric side does not heat water either. I reset that breaker in the panel.
The "soot" appears to be heat discoloration at the exhaust point.

sturgissteele · 06-16-2021, 04:06 AM

Good to hear the pipe was clean, sorry to hear it still isn't working. Sounds like something electrical not working correctly. I'd have to do a little digging to find some more info since I can't recall what all should be checked

Found a little info here, linky. There are other pages the search feature found that might be worth checking as well. Hope you are able to locate the issue. Let me know what you find out.

DooDahDay · 06-16-2021, 03:54 PM

John - Appreciate your help and well-wishes. I may have stumbled onto a piece the issue.*On your hunch, I was testing my way to what might be a bad Igniter Circuit Board - narrowing down the possibilities. Before testing the circuit board I tested the*Thermal Cutoff "fuse" (more like a diode, I think):

1. Removed the thermal*cutoff harness that is inline in the wire to the Thermostat.
2. Connected that wire back to the thermostat, essentially bypassing the Cutoff . (Not recommended for long term, but I think it is ok for*testing)
3. Disconnected shore and battery power
4. Turned*off the gas and depressurized the lines through the stove burners.*
5. Restored power
6. Restored gas and bled air from lines using stove burner

When I flipped the w.h. gas switch on the control panel, the flame ignited, which proves at the very least that the Thermal Cutoff is bad. But now the*flame is soft, billowing, yellowish and smoky, not a tight blue forceful flame. It's possible there is something in the main*burner pipe, the air mixer (as you also suggested), or the regulator. I've even thought that not having the cutoff might impact the flame. That part (#93866) should be here Friday, so I can continue testing if this is not THE fix.*

TCNashville · 06-16-2021, 07:48 PM

The Thermal cutoff is a safety device. In case of a fire, the fusible link will melt and shut down the water heater. This device shouldn't impact the performance of the flame. Sounds like you have some obstruction in the burner tube or inadequate propane pressure.

DooDahDay · 06-17-2021, 03:17 PM

Thanks TC and I agree that poor gas flow would not seem to be caused from by-passing the thermal cutoff. Once I've installed the new cutoff, I'll feel more confident in further troubleshooting, if needed. Thinking to top off the LP tanks and cleaning out the gas pipe and the air mixer section. Just looking for all of the low-hanging fruit before considering big repairs. Wondering how much damage could have actually occurred from running the burner without water in the tank. The tank itself doesn't seem to be damaged and the cutoff seems to have done it's job. Maybe I got lucky...

skids · 06-18-2021, 06:08 AM

I got 4 eco (electric cut off) switches for $15.00 on Amazon. Mine look like a clear flexible plastic tube with a wire and electrical component inside it. When mine fouled, it looked normal but neither the heating element nor the gas would come on. It seemed to test with continuity intermittently. Yeah…with COVID going on at the time, some campgrounds closed off the showers. So, I easily bypassed the eco connections with a wire and made sure it was firing normally so that we could shower.

skids · 06-18-2021, 06:14 AM

By the way, I have adopted a fail-safe of switching off the breaker for the HW element when we are not camping. This can help prevent burning out the element with an empty tank. If you ever suspect that the element might be burned-out, you can unplug it and test for ohms on its plug spades. (10 ohms? not infinity)

Jeffur · 06-18-2021, 06:32 AM

Spiders like to nest in there, use some compressed air and blow it out

DooDahDay · 06-20-2021, 04:11 PM

Thanks to all who jumped in on this. everything mentioned helped to resolve the issues. When the gas burner got things too hot, the thermal cutoff did just what it is designed to do. I imagine it saved the tank, since there do not seem to be any leaks. After replacing the cutoff, the system started working but the flame was very lazy and yellow...not a strong blue flame. I removed 2 set screws in the air mixer/burner pipe and was able to swivel the pipe enough to get a flexible bottle brush in there. There was a fairly solid mass of soot that had built-up in the pipe...also due to the excessive heat. Reamed it through, used the compressor to blow it all out once more and everything works fine now.

TCNashville · 06-20-2021, 05:57 PM

Nice job. Thanks for the follow up as it may help others.

ahaywood5785 · 06-26-2021, 12:15 PM

This was a good thread to see the steps to properly diagnose a WH issue. Thanks OP, and all the posters!

Sbrinson · 06-26-2021, 12:40 PM

It sounds like you’ve successfully resolved your problem. The Atwood water heaters (and probably most if not all others) have safety circuitry that is somewhat similar to what you will find in your furnace. There is a thermostat, a high-temp limiter and the ECO (electric cutoff) which is basically a thermocouple. All of these sequentially pass power to the control module which in turn operates the igniter/flame sensor and the gas valve. If any one of the safety items opens the circuit, the control module won’t receive power and the unit will not ignite. If they all maintain contact and the control module works....but the igniter/flame sensor isn’t working, the unit will not ignite. If everything work and the flame is yellow and “lazy” there is usually something obstructing the gas flow.

There doesn’t seem to be any way of manually lighting the water heaters that have the electronic ignition. Electronic/electrical components can fail with little or no notice. Consequently it might seem prudent to carry the necessary spare parts. If you don’t have the owner’s manual there should be a label in the water heater compartment that lists the model number of your unit. Most of the needed parts are/should be available through RV parts suppliers as well as through online sites like Amazon. I’ve had better luck with control modules manufactured by Dinosaur in the USA.

fpecore8 · 06-26-2021, 12:40 PM

Quote:

Originally Posted by DooDahDay

Hi All - I don't get around to posting very often but I definitely stalk pretty regularly.
Heading out for an impromptu boondocking weekend and had not de-winterized*yet. Yesterday my wife started prepping and for some reason ignited the water heater. I step into the trailer today and noticed the w.h. gas switch on the panel was lit - one of those heart dropping moments because I realized it must have been on all night. Went around to the other side of the trailer and noted sooty stains on w.h. grill and above. Not good. So I got all of the de-winterization tasks completed and filled the water heater. No leaks. But, it will not ignite when I flip the gas switch on. Since we're boondocking, I really don't even want to know right now if the elec doesn't work. We are fine with bucket showers for 2 nights.
Typically when flipping the w.h. gas switch, I hear the igniter clicking and then the whoosh. No clicking, no whoosh. Gas supply*seems ok - I checked the stove.
Any thoughts on the level of*damage done? Hoping it's going to be the igniter panel, if there is such a thing, but the signs of WAY too much heat coming from the w.h.'s vent is bothersome. Appreciate any insight on this... as we all know, this is absolutely, 100% my fault.

So sorry to hear of your hot water issue, I have a 2021 Jayco Bungalow with a hot water tank clicking for the past 4 months, I have notified the dealer and Jayco service and have received no support. The trailer is not in a position to move and even though I have three onsite warranty repairs that apply, dealer told me get lost, the Jayco service told me it’s my issue. It’s almost a legal issue now, sorry I purchased the unit from both parties.

Tony from NJ · 06-26-2021, 02:23 PM

Find your water heater source from inside. Make sure the proper valves are all open and check the wiring there. It’s usually behind a cabinet. We had a very similar issue, long story short - a small white wire had to be replaced, at the heater, from inside.

thenne1713 · 06-27-2021, 05:26 PM

Quote:

Originally Posted by DooDahDay

Thanks for the head's up John. Cleared that pipe, although it was clean. Still the igniter will not engage (click). The Electric side does not heat water either. I reset that breaker in the panel.
The "soot" appears to be heat discoloration at the exhaust point.

MOST WH have a power switch inside the outdoor WH panel that you turn OFF when you Winterize to PREVENT damage such as you detailed? Is it OFF? If so, no damage, put water in and turn switch ON and try again? If it is ON, check any thermostats outside that would trip and have a RESET button or a fusible wire that would prevent fire/ meltdown? If 120vac did reach the electric element, most likely will need a new element, a $15 fix on that side? Brand/ Model # can help? LUCK

jimmoore13 · 06-28-2021, 10:08 AM

A hunch:

How does stuff work?

Your burner is OUTSIDE of the tank. While not great for the tank to run the burner with no water to absorb the heat, it should not be a fatal error when running propane. A possible culprit is the sensor on the outside of the tank (much like a home hot water heater) that detects the temp of the surface of the tank and tells the burner and/or the electric element when to shut off.

The propane heater should NOT be harmed by simply running under a dry tank. It doesn't care. An electric element is submerged in the water, and it will self-destruct when there is no water.

So,
A) You found that the thermal protection switch did its job and failed.
B) Consider that the tank's temp sensor may have been cooked as the propane burner repeatedly heated the empty tank to high temperatures. Without the buffering effect of water in the tank, that temp sensor may have been cooked by the high tank body temp.

On a home hot water heater, these sensors sit outside the tank and press against the hot water tank body. The sensors typically are small, round "buttons" that touch the tank, and the rest of the sensor mechanism is wiring connections and a temp control setting...thermostat.

Your thermal protection device can easily be replaced (and bypassed as you did), but if you still have problems, look into the device that actually senses water temp (tank body temp) and switches the heater on and off.

I grabbed this video at random. It may be helfpful.

https://www.youtube.com/watch?v=FuBoRRojKcA

Poke around a bit. My search term: "water temp sensor on rv hot water heater"

If you cooked the t-stat, it's easily replaced.

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