DuraVent FasNSeal Test Port: check the exhaust without drilling the vent
The DuraVent FasNSeal Test Port is a short length of stainless steel vent pipe with a plugged opening for testing exhaust. A technician removes the rubber plug and inserts an analyzer probe to check how the appliance is burning. The plug goes back after testing. This provides access without drilling a hole in the vent, which DuraVent does not allow. DuraVent does not specify a fixed location for this part in the run. FasNSeal is DuraVent’s stainless steel vent for high efficiency gas boilers, furnaces, and water heaters, built to carry pressurized exhaust and its acidic condensate outside.
Choose a size from 3 to 16 inch on this page to match the vent run. FasNSeal serves natural gas or propane appliances whose maker calls for a special gas vent. Each part has a gasket and a built in locking band at its wider end to seal and secure the connection. Need the double wall version? See the DuraVent FasNSeal W2 Test Port double wall fitting. The DuraVent FasNSeal Test Port ships free from My Cozy Outdoors with No Sales Tax (except WY) and the full manufacturer warranty.








Commercial projects may require custom parts and unique system designs. Duravent offers complete project assistance:








































