Hi,

I noticed something that looks unsafe about my wall heater. It is an old Williams wall heater. I am not sure about the proper terms for the parts involved, so please bear with me.

Basically, the gas comes from the shut-off valve, goes into the gas valve (the box with wires attached to), and then goes out through a metal pipe from the top of the valve box. Now, this pipe does not go straight into the burner. Instead, there is a gap in the pipe, separating the pipe that comes from the valve and the thicker pipe that goes to the burner. Unfortunately the gap is hidden by a metal flange (the flange is shown in the second picture), so you can't actually see it in the picture. I am not sure what is the purpose of this gap - some safety mechanism maybe?

Anyway, today I noticed a flame in the gap area, behind this metal flange. I don't think this is normal. I blew it off and shut down the heater. I am not sure what could be the reason for this or if it is safe to operate the heater. I would appreciate some advice.

Thanks,

Ron

 

Yeah that is old. Sounds like the gas pressure might be low.

 

On way to burn fuel is like a candle flame. If a candle flame impinges on metal, it will make carbon monoxide and soot.

Another very popular method is to use a Bunsen burner. This type of burner injects gas into a venturi tube where the jet of gas pulls in room air and mixes it with the gas. The gas then burns on top of the burner, using additional air surrounding the burner flame to complete combustion.

Because of the added air, a properly adjusted Bunsen Burner doesn't make carbon monoxide.

You have Bunsen Burners on your wall furnace.

There is a burner orifice at the end of the pipe coming from the gas valve that forms a jet of fuel gas and sends it into the gap you describe, which is the venturi where the fuel gas and air mix together. The gas is then carried into the burner by the forc3e of the flow of gas, and should burn on the top of the burner.

What you describe appears to be called "flashback" where the gas burns in the venturi rather than on top of the burner where it should burn. This is usually fairly noisy when it happens.

Fuel gasses burn at a certain number of feet per second. If the gas is traveling too slowly, it wont burn on top of the burner where it should but will burn at the venturi ---- which is what you appear to be describing.

So you have some defect which is slowing down the gas.

That can be any part of the burner which is dust laden (a common problem in wall furnaces.) It could be a burner orifice which is partially plugged up, or a gas supply pressure that is too low.

Do you have propane or natural gas? Do you have other gas appliances, and if so what? Do any of these other appliances seem to be burning in an odd fashion? If any of these are true, you might have a gas pressure problem, although that would be uncommon.

Much more common would be having dirty burners that need to be taken apart and thoroughly cleaned of dust and dirt. It It looks like the pilot burner should be disassembled and the pilot burner and pilot orifice cleaned as well, although that's not causing this problem.

 

Welcome to the forums.

You could have low gas pressure, partially plugged orifice or a spider web in wrong place.
With the age of that unit it would be a really good idea to have it professionally cleaned.

 

The ony effective way to clean a Williams burner is to remove and wash with a hose. On some models there is a spreader plate inside the burner that multiple small holes. The holes become clogged with lint and need to be washed to establish a proper flame.

 

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Mmmmm. I've never washed out a Williams wall furnace burner.

I don't recognize the spreader plate you describe. As I recall, there is often a screw that runs down into the venturi that probably creates some additional turbulence to mix the fuel and air, but I don't recall seeing the plate you describe.

 

To see the plate you must remove the burner and with a flashlight look thru the burner slots. I washed I dare to say hundreds or at least it seems like. Actually most guys are not familiar with the spreader plate. I had a single wall burner I used for a demo in my classes. Also on some single Williams burners the orifice was not aligned and that produced a luminous flame which led to soothing. I've corrected many of those. Seems like Williams furnaces were the replacement of choice around here for years. The screw you mention I believe we're almost always on cast iron burners like the old Holly's or Custom Air. I think the burner in above picture is one with the plate

 

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Add me to the list who never looked into the burner slots.

Still, cleaning out the burners with wire brushes and compressed air always did the trick for me.

 

Lol. Yes that worked on most burners. The Williams were just a little more difficult, so we trained the crew to pull and wash if air didn't work. Seemed like it was the single walls that needed added attention. Did you ever encounter the out of align orifice. Mostly on the single wall horizontal orifice burners

 

Those are definitely a West coast thing. I don't think I've ever seen any here on the East coast.
(at least not in NJ)

 

Could be. I know years ago there were several regional brands. Ever hear of Heatwell- Clipper or Western to name three.

 

My most amusing experience with a Williams Wall Furnace:


Wall furnaces have no filter and are famous for getting loaded with dust and dirt.

I was in a woman's apartment one time, and the wall furnace was full of dust and dirt.

I told the lady I could refer her out to a furnace cleaning company, or I could use a high pressure tank of nitrogen and a regulator and blow the dust out for her. She wanted me to do the job.

Well, I hit that wall furnace with a jet of nitrogen that was pretty powerful, and highly effective at blowing out the dust. It was like turning out the lights in the room ---- dust saturated everything!

The lady was still happy to get her furnace up and running at no charge (I was working for the gas utility at the time), but she must have been dusting for a week ---- maybe a month!

I never saw a wall furnace with as much dust in it.

 

And. When you light a match to light the pilot all the dust on the side goes up in flame. Good to have a soap bottle handy