Heating, Air Conditioning, Fridge, HVAC/Furnace Intake pipe break


We returned from work yesterday to find the house at 55 degrees. It is zero outside now.
Went to the basement and found the intake PVC pipe for our furnace on the floor and broken in pieces and the furnace silent.
I flipped the power switch on the side of our Carrier 58MXA furnace and noting happened.
There is about 10 feet of pipe still attached to the furnace section, the piece going to the outside wall is broken right at the outside wall elbow and there is about 22 feet of pipe broken laying on the floor in between.
I took the section of pipe attached to the furnace that was tilted down to the floor and wired it back to the floor joists, cycled the switch and the furnace came to life and seems to work normally. The house temp is up to 62 after about 6 hours running.

Question is: As this is the combustion air intake pipe, can I leave the furnace use the basement air for intake until the weather gets warmer (maybe above freezing) before repair?? We are expecting sub-zero temps for the next 2 days, minus 14 tonight.

Thanks in advance
Dean in Northern Illinois

ANSWER: Hi Dean, yes you can use the basement air for intake. Some installers do it this way with no problems. I am curious why this happened. Was the PVC glued?


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QUESTION: Hi Jim and thanks for the reply,

The 3 plastic 'J' hangers seem to have failed and 1 joint was not glued and another just had a dab on it. The 45 going to the outside wall broke completely.

Another question..... Could drawing combustion air from inside the house create 'negative' air pressure in the house (with the exhaust still pumping outside), and cause extra cold air infiltration from outside?

The house seems to be heating up quite slowly.

Thanks again,

Dean, Yes it could cause a slight negative pressure, just depends on the size of the house. I always run both to the outside, so I would go ahead and replace it. This is not something that needs to be right away.

As for the house warming up, that sounds normal to me, with temps in the single digits outside. If the house was at 55*, then you can expect about 95* coming out of furnace. That temp will increase as the house warms.


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Jim S.


I can answer questions on gas or electric furnaces, ac units and heat pumps. I don't work on boilers,chillers,or home appliances.


I have been in the HVAC trade for over 35 years. For the past 15 years I have owned my own business. I am semi-retired so I can answer questions in a timely manner.

I attended trade school for 5 years on weekends and evenings. This was very hard to do, but well worth it!

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