Propane furnace gas valve settings

[pnora]

As the topic says. I am installing a new Tempstar furnace in my shop tomorrow. I need to convert the unit from natural gas to propane. It is a single stage. I have the kit and pretty much understand everything. It has a low pressure propane kit that I also need to install or the warranty could be voided. Again I pretty much understand its install and function. What caught my eye is the pressures. They want 12.0 min. WC to 13.6 max in WC for inlet pressure. Then they want 11.0 in WC for manifold pressure. Seems high to me but who knows whats changed through the years. I am used to 11.0 . WC and 3 to 7 . WC on the manifold depending on single stage or two stage. Any pros here with an opinion.

 

[Don Frelier]

Propane supply pressure is normally measured in inches of water column.
1 Psi = 27.7" of H2O

Variation of +/- 1" of water column is a small variation in pressure.

 

[eldubb440]

 

[pnora]

Propane supply pressure is normally measured in inches of water column.
1 Psi = 27.7" of H2O

Variation of +/- 1" of water column is a small variation in pressure.

Thats why all my numbers have WC .

 

[Don Frelier]

Pound per square inch and inches of water column are different units of measurement.
I showed the conversion.
You mixed the two units in your description.

 

[pnora]

Pound per square inch and inches of water column are different units of measurement.
I showed the conversion.
You mixed the two units in your description.

I see what you mean. I deleted the PSI.

 

[hunt2elk]

I would question the 11" as I don't ever remember any wanting that high of pressure. Most brands used to specify 10.5" max, but everything I've been seeing the last several years now wants 10.0" max. That is just the brands I have been dealing with however.

 

[moparwacko]

 

[pnora]

I would question the 11" as I don't ever remember any wanting that high of pressure. Most brands used to specify 10.5" max, but everything I've been seeing the last several years now wants 10.0" max. That is just the brands I have been dealing with however.

Here is a copy of the conversion sheet. I had my doubts but I find this is seems to be correct.

 

[bm02tj]

Norm for natural gas is 3.5 in WC and yes propane is smaller orifice and needs more pressure to entrain needed amount of combustion air as one is 1000 BTU and propane is 2500 BTU per cubic foot

 

[pnora]

I would question the 11" as I don't ever remember any wanting that high of pressure. Most brands used to specify 10.5" max, but everything I've been seeing the last several years now wants 10.0" max. That is just the brands I have been dealing with however.

I finished the install. Had to adjust the inlet pressure to 13.0 WC and the manifold to 11.0 WC. It was very interesting to see the burners change with the increase in WC. bringing the inlet up changed it and setting the manifold to 11 changed it even more. Anyone doing an install or maintenance should always check these pressures. Your furnace will heat and perform better which is good for the life of the unit as well as the efficiency. You will actually make cleaner better heat along with using less fuel. A simple Menards manometer is 39 bucks. Worth every penny.

 

[Don Frelier]

I finished the install. Had to adjust the inlet pressure to 13.0 WC and the manifold to 11.0 WC. It was very interesting to see the burners change with the increase in WC. bringing the inlet up changed it and setting the manifold to 11 changed it even more. Anyone doing an install or maintenance should always check these pressures. Your furnace will heat and perform better which is good for the life of the unit as well as the efficiency. You will actually make cleaner better heat along with using less fuel. A simple Menards manometer is 39 bucks. Worth every penny.

And you'll save more money at Menards

 

[bm02tj]

For one time only clear tubing and water and then measure distance