Water Heater Ignition Problem

07-08-2003, 07:17 AM

Hi all. I've got a 1990 M23 (3023). Love our TM. But... The water heater is not lighting properly - all the time. ??? Sometimes it fires up fine, others not. It's a 3 gallon gas only model. Now the problem.

When the heater lights the main burner, the gas sometimes burns in the main burner tube. I have taken everything apart, cleaned, reassembled, all for nothing. The air mixture is OK, I have checked that multiple times. When the heater fires in this manner it burns very rich, you can smell the sooty smell and it is depositing soot on the side of the TM above the heater exhaust grate. When lit, it makes a high pitched sound as the air is pulled in wrong. Remember, this problem is intermitent. When it lights normally it works great.

I'm out of ideas and thinking of replacing the gas valve assembly. Anyone out there have another idea?

Thanks,
Camperboy

**mjlaupp** · 07-08-2003, 08:17 AM

The problem is in the gas nozzle. It only takes a small speck of dirt to partially close the nozzle. When this happens, the gas is not injected into the air manifold in a smoth manner. The particle of dirt in the line will sometimes lodge in the nozzle and sometimes not. If you can take the nozzle out and then blow through the gas lines and the nozzle with a non-combustible gas you may be able to clear the problem. DO NOT use a wire to poke through the nozzle to clean it. If you scratch the nozzle orifice you will distort the gas flow and the problem will never go away. The nozzle probably got dirty from some contamination that was on one of your tank connecters after the tank was refilled. This is also the type of problem that could be expected when teflon tape is used for gas connections. You may want to look for a replacement nozzle especially if the nozzle shows signs of corrosion.
MJL

07-08-2003, 09:02 AM

Thanks for the idea. I'll check it out.

Camperboy

**Bill** · 07-08-2003, 12:21 PM

Quote:

The problem is in the gas nozzle. It only takes a small speck of dirt to partially close the nozzle. When this happens, the gas is not injected into the air manifold in a smoth manner. The particle of dirt in the line will sometimes lodge in the nozzle and sometimes not. If you can take the nozzle out and then blow through the gas lines and the nozzle with a non-combustible gas you may be able to clear the problem. DO NOT use a wire to poke through the nozzle to clean it. If you scratch the nozzle orifice you will distort the gas flow and the problem will never go away.

Mike -

Wow - good answer.  I have heard of this problem, but never heard a coherent answer.  Yours makes good sense, and I will stash it away.  One question.  You say not to use a wire to clean the orifice.  Makes sense, since a hard wire could scrape new features into the critical soft-metal surface of the orifice.  Could you clean the orifice with a piece of nylon (monofilament) fishing line?  I would think you could push this through the opening without fear of scratching the soft brass.

Bill

**mjlaupp** · 07-09-2003, 02:45 AM

Anything softer than brass can be used to clean the nozzle. Fishing line would be fine.
MJL

08-13-2003, 01:01 AM

Camperboy,

Did you get the problem fixed?

ColoradoCop 8)

08-13-2003, 01:51 PM

Not sure. I have worked on it and test fired it. Seems good so far, but have not had it out since for a real world test. We tend to not camp in the summer in the northeast, too hot. Much prefer cool days and crisp evenings. Now if I could get out to Colorado in those 14,000 foot mountains again ... RockyMtnRay has been giving me the road trip itch with those posts w/ photos!

I'll keep ya posted.
Thanks!
Camperboy

**Brightsu** · 08-25-2003, 09:05 AM

We had a problem getting our w.heater to work also, did the pipe cleaner thing still didn't work, took the whole assembly off blew thur it with air compressor and then took the small copper piece out of tubing and that was the problem a tiny piece of dirt was blocking the tiny hole, when I say tiny you need a magnifying glass to see it then I held a light under it and the hole was open and now it works. I have a 95 3326, and it had been setting up a long time, we've only had it since May.

Thanks Guys,
Pam ;D

09-16-2003, 09:31 AM

I had a similar problem with an outdoor heater and used the dust spray that you can buy at a camera store to blow out dust. It is compressed air and it produces a forceful spray without the risk of damaging the orafice. That usually works and it will not be necessary to take the device apart.

10-15-2003, 08:56 PM

Well, finally got out for a week. The water heater on the TM is still acting the same. Took it apart and cleaned it again with no luck. Short of using a metal cleaner like Noxon and a q-tip and polishing the orifice, which I am thinking of trying. So does anyone have any other ideas for me? The orifice appears to be clean, though I haven't checked it with a magnifier. I'll keep you posted of any progress I make with this.

Think that RVs just like to give me something to do. Our first, a 1983 Coachmen pop-up gave me all sorts of grief, finally a cracked frame and major roof rot, and totally worn out torsion suspension was more than I was goning to take. Gave it (the frame) away, stripped. Think the guy repaired it and made a utility trailer. Anyone need canvas for a pop-up? So this week, the TM leaked over the door (roof), the left rear brake/turn lamp stopped working, and the water heater persisted. But don't be looking for me to give it up!

Camperboy ;D