Draft control location for gas

Dale

Although Timmie has by far the most experience with conversions I noticed something in your post. The 7" vent size for 140K seems way too large. When we did a lot ofconversions we sometimes reduced from 8" to 5 or 6". The burner needs to be set up with an analyzer to get the most efficiency and lower flue gas temp. sometimes the vent connector needs to be restricted. Most important a very good cleaning of the flue passages first and per code a chimney clean.

Peter Zelchenko_2

Draft control location for gas

I am converting a residential boiler from oil to gas. The present draft control is located on the vertical flue pipe that rises less than 3-feet to an elbow and then runs to the chimney at the wall on a four foot run.

The Field Controls instructions indicate that this same location is "acceptable" but a bull-head tee is "best".

I like doing things the right way, but am not sure what benefit the extra labor will result in. The burner burns 140K BTU into a 7-inch flue pipe. The new draft control uses a 8-inch ring.

Any advice?

Steamhead (in transit)

That bull-head tee

is fine for atmospheric burners. But since you're using a power gas burner, the present location will work fine.

The difference is your power burner uses a fan to supply the air, just like an oil burner.

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Peter Zelchenko_2

Thanks

Unknown

The reason for

the bullhead tee is to insure that if there is a downdraft it does not enter the combustion area but dumps into the room. This is critical with gas as we can not have raw gas escaping into the chamber and with a downdraft into the chamber it can put the flame out.

Unknown

Dale is correct,

I did not pay attention to that I was more concerned about the barometric. The vent should be sized according to the conversion burner manufacturers instructions. Many times this will result in a reduction in size at the breach of the boiler.

There are a lot of people all of a sudden installing conversion burners and I am sorry to say they do not know what they are doing. I have been out on seven different installations in the last two weeks all with multiple installation problems and failure to properly clean and refurbish the boilers. In some cases the oil flue and barometric left in. One had a draft hood from a Burnham gas design boiler installed along with the oil barometric. Another one had four flexible connectors hooked together to get gas to the burner. The air leaks on that one was causing CO levels of over 700 PPM and higher, I pulled my tester at that level.

The customer on two of these paid $4,000 for the installation. The two guys installing those two are electricians.

The cost of oil is driving a frenzy to change to gas, I sure hope nobody gets hurt.

Without training you should not be putting in power gas conversion burners.