Chimney lining?

DeePaz3

I just switched from oil to gas and I was wondering if anyone knows if I must line my chimney. One plumber told me I must line it another told me becasue my chimney is in the center of my house and not on an outside wall that i do not have to line it. Does anyone know if this is true?

Tim McElwain

What kind of system do you have

that was on oil and is now on gas, Forced Hot Water, Steam, Forced Warm Air??



Did you install a gas conversion burner into the existing appliance?



Is your chimney unlined or does it have a clay tile liner?



Most equipment today that is gas must have a liner or at least use the existing chimney as a chase using a type "B" double wall gas vent or flexible liner (20% less capacity than a "B" Vent.).

Bob Harper

inspection and relining

You should have a pro conduct a :Level II inspection. That will determine the condition and suitability of the chimney. You should provide the inspector with the BTU/hr input firing rate and appliance collar size so he can advise if the chimney needs a liner for sizing purposes, too.

Having said that, it is adviseable to reline all masonry chimneys with a properly sized listed liner. A metallic liner will heat up quickly for a strong draft, contain the byproducts of combustion, prevent flue collapses blocking the flue and allow the appliance to operate at its intended efficiency.

When switching from oil to gas, you should have the chimney swept to remove as much of the oil soot as possible. You will want to use a type 316Ti stainless steel liner, which will not only be compatible with the gas but will remain resistant to the oil soot left in the chimney. Get a liner with a transferrably lifetime warranty. Have the room assessed for adequate makeup air.

The liner should be installed by a professional chimney contractor. It should include all stainless top plate and rain cap/ animal guard. The crown of the chimney, pointing and flashing should be repaired as indicated by the inspection. Inside, the chimney pro should run the vent connector using all new pipe. Consider using B-vent instead of single walled pipe. You want as much vent rise off the top of the appliance as possible before any offsets. Make sure the connector is properly supported with clearance to combustibles.

Once the chimney has been relined, then a pro certified in carbon monoxide and combustion analysis should test the system for proper venting and combustion and tune accordingly.

HTH,