What would cause my water heater to smoke?

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.

JDMAG

Well-known member
Joined
Jun 23, 2010
Posts
48
Next question! (I'm off today so I play) What would cause my water heater to smoke like this? it was heating and then I noticed this.
http://i379.photobucket.com/albums/oo234/lybrookj/Mobile%20Uploads/IMG-20120315-01865.jpg

http://i379.photobucket.com/albums/oo234/lybrookj/Mobile%20Uploads/IMG-20120315-01866.jpg
 
Smoke like that typically means not enough oxygen - fuel mix is too rich.  A likely cause is blocked air flow - wasp nest, dirt daubber, spider web, etc.
 
What is the block on the bottom of the bottom picture that looks like it's blocking the air intake vents in the burner tube? I agree with Molaker...definitely burning rich. If it's not that block obstructing the air, then pull the burner tube off and check it for an obstruction.
 
Water Dog said:
What is the block on the bottom of the bottom picture that looks like it's blocking the air intake vents in the burner tube? I agree with Molaker...definitely burning rich. If it's not that block obstructing the air, then pull the burner tube off and check it for an obstruction.
I'm pretty sure that's a wind deflector and is supposed to be there.
 
I will investigate this again in the morning. Once again Thanks for the advice. Friendliest place on the innernet!
Could you discribe the air mixture valve so I know where it is?
 
On the gas feed to the burner tube you will see a sleeve over the tube that has air openings. There is a set screw that holds it in place. Loosen the screw and slide the sleeve a bit to enlarge the openings. That lets more air into the gas mixture.  That's the same area and tube that you should check for blockages, e.g. mud dauber or spider nests.

In your second picture, the air mixture admittance sleeve can be plainly seen at the bottom, just to the left of the igniter.
 
If it has been a little while since the last usage, it is likey a paper nest inside the burner,  I had the same  thing happen on mine a time back.  Paper wasp nest gets inside and once you start it up, it burns smokey.  Look in with the flashlight, will probably see remains.  If it is a nest like this, the smoke will stop soon as it incinerates, if it is the air mixture it will continue.  If air mixture you may notice the sleeve is loose, because it wasn't doing that before, right?  If tight, not lileky it is the mix.
 
While the heater is burning just look into the tube if the flame is lazy and yellow your air shutter is closed too much or the burner tube is blocked up. I would open the shutter fully and using compressed air I would blow the crud out of the burner tube and then reset the shutter back to the orignal position. Then check your flame again. Worse case you might pull the tube completely off to clean it.
 
Ditto the above replies.  I have problems with spider nest in the burner tube all the time.  Not a big deal to clean it out.  Check the gas orifice too for obstruction.

The only other thing I can add is I had a similar problem way back when I had a propane tank close to the empty mark and the auto regulator didn't switch over to the full tank for some reason.  Not sure why.  Problem wasn't severe enough to effect frig. pilot.  But the water heater acted as your did.
 
The following is from the manual for my Atwood water heater. My problem was due to the spreader tube being misaligned.

SMOKING AND SOOTING

CONDITION _____________________SOLUTION
? Gas pressure incorrect ___________ Set pressure to a minimum of 11? W.C. with two or more appliances running
? Poor gas supply________________? Replace gas supply
? Improper pilot flame _____________ Clean or replace pilot orifice
? Improper air adjustment__________ Adjust main burner air shutter approximately 1/4 open
? Flame spreader misaligned _______ Realign or replace main burner
? Blocked main burner ____________  Remove blockage

? Improper main burner alignment____  Realign main burner, main burner orifice holder and gas valve
? Blocked ?U? tube ________________ Remove blockage
 
Dang Spiders! working good now. but it was clogged between the air mixture valve and the end of the tube. Now How can I tell if this unit has both Gas and electric option on the water heater? there are 2 switches inside on the monitor panel. (3 counting the water pump switch) one I know is the gas water heater, the other says water heater also, but does not illuminate when I turn it to the on position. so I assume its an option that isn't there, or it isn't functioning properly. I appreciate the learning experience I am getting!
 
The switch doesnt light up, but the water heater does work electrically.
 
The lit switch is usually for gas, will only light for fault.  For instance you turn it on, the igniter attempts to light, if after a short time it is not lit up, it gives up and lights that indicator.  This is a typical installation anyway.  YMMV. 
 
It has a seperate fault light for that. DSI FLT  what is the YMMV?
 
Well every thing seems to be in working order now Thanks to ya'll and a couple of emails to Dutchmen. 8) :eek: I appreciate the info. I know I'll be back.  and PancakeBill....MTFBWY!.. ;D lol
JD
 
Like in my RV the 110 VAC element has a seperate switch on the wall like a normal house wall switch. But the gas water heater switch is on the monitor with the tank levels.

 
Back
Top Bottom