Airease 95G2DFE, Installation Instructions Manual

507206-01

Page 46  of  59

Issue 1337

Testing for Proper Venting and Sufficient Combustion Air for Non-Direct Vent Applications

After the gas furnace has been started, the following test 

should be conducted to ensure proper venting and sufficient 

combustion air has been provided to the unit as well as to 

other gas fired appliances which are separately vented.

If this furnace replaces a Category I furnace which was 

commonly vented with another gas appliance, the size of the 

existing vent pipe for that gas appliance must be checked.  

Without  the heat of the original furnace flue products, the 

existing vent pipe is probably oversized for the single water 

heater or other appliance.  The vent should be checked for 

proper draw with the remaining appliance.

The test should be conducted while all appliances (both in 

operation and those not in operation) are connected to the 

venting system being tested.  If the venting system has been 

installed improperly, or if provisions have not been made 

for sufficient amounts of combustion air, corrections must 

be made as outlined in the previous section.

1.  Seal any unused openings in the venting system.

2.  Visually inspect the venting system for proper size 

and horizontal pitch.  Determine there is no blockage 

or restriction, leakage, corrosion, or other deficiencies 

which could cause an unsafe condition.

3.  To the extent that it is practical, close all building doors 

and windows and all doors between the space in which 

the appliances connected to the venting system are 

located and other spaces of the building. 

4.  Close fireplace dampers.

5.  Turn on clothes dryers and any appliances not 

connected to the venting system.  Turn on any exhaust 

fans, such as range hoods and bathroom exhausts, so 

they will operate at maximum speed.  

Do not operate 

a summer exhaust fan. 

6.  Follow the lighting instruction to place the appliance 

being inspected into operation.  Adjust thermostat so 

appliance will operate continuously.

7.  Use the flame of a match or candle to test for spillage 

of flue gases at the draft hood relief opening after 5 

minutes of main burner operation. 

8.  If improper venting is observed during any of the 

above tests, the venting system must be corrected or 

sufficient  combustion/makeup  air  must  be  provided.  

The venting system should be resized to approach the 

minimum size as determined by using the appropriate 

tables in appendix G in the current standards of the 

National Fuel Gas Code ANSI-Z223.1/NPFA 54 in the 

U.S.A., and the appropriate Natural Gas and Propane 

appliances venting sizing tables in the current standard 

of the CSA-B149 Natural Gas and Propane Installation 

Codes in Canada.

9.  After determining that each appliance remaining 

connected to the common venting system properly 

vents when tested as indicated in step 3, return doors, 

windows, exhaust fans, fireplace dampers and any other 

gas burning appliance to their previous condition of use.

CARBON MONOXIDE POISONING HAZARD

Failure to follow the steps outlined below for each 

appliance connected to the venting system being 

placed into operation could result in carbon monoxide 

poisoning or death.

The following steps shall be followed for each appliance 

connected to the venting system being placed into 

operation, while all other appliances connected to the 

venting system are not in operation.

  WARNING