Cleaning sooty water heater: what's the easy way?

[amm3824]

I need to clean out my sooty hot water furnace, as I suspect something in there is blocking the air flow, causing it to run rich. I can see the yellow flame when I look into the exhaust port, so the blockage probably isn't too bad (and this thing is about 800 miles new!).

I've read that removing the furnace and cleaning it out might be the way to go, but I find it hard to believe there isn't an easier way. What's wrong with snaking a pipe cleaner in there and blowing it out with compressed air? Correct me if I'm wrong but isn't the tube just a continuous tube, with nothing else in the way? Or is there a fan or something in the tube? Seems like there should be plenty room to snake something in there and break the crud or mud daubers free and whoosh them out the exhaust port with a blast of air.

Sure beats disconnecting the entire unit, breaking the weather seal, pulling it apart, etc... at least in terms of time.

[pmclemore]

I hope an expert will chime in, but a yellow flame is not what you should be seeing; the flame should be more blueish. Perhaps a spider or wasp has blocked part of your jet.

Good luck - Pat

[Aage]

Hi, Andrew!

Welcome to the world of repair! Yep, it even can happen on the brand-new trailers like yours!

First, let's get the names right: I THINK you talk talking about your water heater.

The furnace is what heats your trailer, the water heater, you guessed it: it only heats the water! And as my brother likes to jump on me to say, it's not a HOT water heater, 'cause if the water was hot, why would we heat it! He's a character, that brother...

So, the other thing is, you don't ever have to take out the water heater to clean it; the only time is comes out is if you have to replace it.

What gets plugged with stuff is the tiny little nozzle that points into the large U-shaped tube in the bottom right that disappears into the tank. The much larger silver nozzle supplies fresh air and the tiny nozzle supplies gas.

Cleaning them is fussy: it's soooo small an aperture that you have to be really careful. I just used brake fluid on mine this weekend past.

On my water heater there are two tiny tubes ritgh beside each other. The second one is a thermocouple. But your trailer being so new, I would be almost certain that you have a piezoelectric starter, and that system does not use a thermocouple.

Good luck, and hang in there, more knowledgeable help will surely show up soon!

Other more experienced folks will chime in and tell you if that's a good or bad idea.

[amm3824]

Ahhhhh okay, now we're making progress... All this time I was thinking what needed to be cleaned was the giant U-shaped tube that goes from the flame source to the exhaust outlet.

So... sounds like the problem area might actually be in the nozzle where air/fuel is ignited?

I was thinking it seems pretty unlikely that a blockage would occur in the giant U-shaped tube - and if it were, it would be burned up pretty quickly with the flame.

Can someone confirm? I really need to tackle this soon - got a camping trip on the horizon...

Here's a shot of my water heater

[tpi]

The tube with the slots and the screw in the lower left of your pic is the place where the spiders built nests in mine. These partially clogged the tube and caused yellow flame and soot streaks on the trailer exterior.

I removed this "mixing tube" and cleaned it.

[amm3824]

Okay, finally tackling this project. I removed the air tube assembly (together with igniter controller box thing) -- now I'm staring down into the L-shaped, 1-inch diameter silver tube with the air inlets. No sign of any blockage; I can see pretty much everything in there.

So I'm still baffled as to why there's a yellow flame.

Do I need to look at the gas nozzle itself? -- that is, the brass fitting with a tiny tiny aperture (pinhole sized) that shoots gas into the 1-inch tube? No obvious blockage there but I guess it wouldn't hurt to gently clean that.

Other ideas welcome...

Off to clean the gas outlet.

[amm3824]

Followup - well I removed the air inlet assembly (L-shaped tube about 3/4 to 1 inch diameter), no obstructions there. Then cleaned the tiny (less than 1 mm diam.) gas nozzle - I think this may have done the trick. Ran water heater for a few minutes, flame is mostly blue, with a little yellow. I think it's all set now. Thanks for all your help.