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BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22519
Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
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my furnace shuts off on windy days. It is side vented (90 degree

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my furnace shuts off on windy days. It is side vented (90 degree angle) from furnace to outside wall. worked well for about 5 years. finished basement and enclosed furnace, hot water, washer, dryer in room. that started the shut off problem. told it was wind back draft and installed 90 degree up-right exhaust (about 4 feet up) with rotating cap on top. did not solve problem. solutions range from "get new furance" (it's only 9 years old) to "install fan-in-a-can" or an exhaust vent fan, or both. any advice on "honing in" on correct avenue to explore? thanks
Submitted: 5 years ago.
Category: HVAC
Expert:  BillyHvac replied 5 years ago.




If it ran for 5 years fine...I am led to believe it is not wind related....unless you didnt have winds for 5 years.


My bet is either a heat exchanger starting to get plugged a little, a weak pressure switch, or another obstruction that is partial somewhere.


This would make the unit more "sensitive" to the wind and cause fault. I think the extention and caps are heading the wrong way. If it ran 5 years ok....I would start with clearing the exchanger, checking static pressure of exhaust fan, static of pressure switch and drain from furnace.


I would think something else is adding to the issue and the wind just puts it over the edge.



Expert:  BillyHvac replied 5 years ago.

where does the furnace get its air from for the burner now?



Customer: replied 5 years ago.

air is from the room furnance is in. the various service and parts replaced was done. that is why it was narrowed down to the wind problem -- some say its wind not letting the exhaust vent out and the carbon monoxide sensor is shitting it down, otheres saying it is not getting enought outside air, causing it to shit down. that's why all the different solutions to solve the air problem.

Expert:  BillyHvac replied 5 years ago.

Do you have a transfer grill for the combustion air?...and why was the combustion air not piped to the outside?



Customer: replied 5 years ago.
I dont know about a transfer grill? and the combustion air (isnt't that the exhaust?) is vented to the outside -- that's what i was refering to. The piping that would go to a chiminey was side piped to the outside side basement wall. that worked until room enclosed and then was extended upward.
Expert:  BillyHvac replied 5 years ago.

correct...but most 90% units have a second pipe to outside so the furnace does not use house air...thus sucking cold air in wherever it can...all the air being exhausted must come from somewhere...and without the second pipe to outside the huse becomes negative pressure.


what is make/model

Customer: replied 5 years ago.
its a luxaire, rated at 80,000 btu. with 3-ton cooling system. not sure of model (in a rental i have). no second pipe--which was why one person said can-infan was way to go. hesitant because it worked for so long without. just getting air from basement. after enclosing the utilities, problem started, which is why another just said install grill openings in utility room walls. big difference, so just want to see what is right direction.
Expert:  BillyHvac replied 5 years ago.


I think the unit is starving for air.. The grills will surely help. But an outdoor air pipe would be the best.

Customer: replied 5 years ago.
is an outdoor air pipe the "fan in a can" or is it something else?
Expert:  BillyHvac replied 5 years ago.
No...your furnace is already set up for a another pipe...all you would have to do is install the pipe to the outside just like the current exhaust pipe. With model number I could show you a manual.
Customer: replied 5 years ago.
okay, great. when i get model number can i go to manufacturer website for manual to see? can u give me a link? thanks
Expert:  BillyHvac replied 5 years ago.




if you need further help let me know.



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