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Discussion Starter #1
Hello all,

While my parent's furnace is running normally, it seems that airflow has dramatically reduced throughout the house. One example is their main floor powder room used to get blazing heat/cooling and now little to no airflow at all. All rooms on the main floor and upstairs seem to have little to no flow, and the only room that gets visable airflow is the kitchen that is the closest to the furnace that is in the basement.

The home is 3200 sq.ft. furnace is 100,000btu and i've checked the filter and attempted to clean the blower wheel fins without and difference.

Would a duct cleaning do anything, it's never been done as I think it's a waste of $$

Thanks to all who shine some light.
 

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The motor capacitor may be weak and if it is the original motor then there is a 95% chance it is weak/slowing down/seizing up. At 20 yrs old you may want to seriously consider a new furnace soon as the heat exchanger may fail soon and your repair $$ will go to the scrapyard along with the furnace.
 

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Discussion Starter #4
Well looking at the evaporator inspection is nearly impossible without a boroscope or making a hole in the plenum.

yuri, doesn't the capacitor simply just start the blower motor? The capacitor for the draft inducer looks similar can it be swapped?
 

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No and No. The blower motor is a PSC Permanent split capacitor motor ( google that for more info) and needs it to get up to speed and create torque. Capacitor start/run motors are totally different and have a centrifugal switch to disenagage the start winding and capacitor on larger motors or belt drive motors. Windings degrade/short with old age and motors lose their horsepower and also seize up. The capacitor on the inducer is too small. Some parts for those units are very hard to get or obsolete, pressure switch made by TriDelta is one and depending on the model some of the burners are rotten and have flames coming out the sides and are definetly obsolete.
 

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Discussion Starter #6
Thanks yuri, man you sure know a lot. Honestly, i've looked at the burners and they are REALLY burning nicely for the age. I don't know what to tell the old man. I said it's going to be time to replace soon but maybe he'll get a few more years out of the unit??

What would a blower and capacitor run parts wise? I am sure I am capable on replacing them. I always thought the time to replace the motor/capacitor is when it wouldn't start to run.
 

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I suggested evaporator because you said you cleaned the blower wheel and why would you do that unless it was dirty? If it's dirty, the coil's dirty.
 

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Nyet. They can progressively slow down. You can probably buy a motor, may need a 1/2 hp on that size furnace and a capacitor and probably will need a belly band adaptor mount for under $100 at a electric motor shop or Acklands/Grainger. Make sure you get the rotation right after starting it. He may get a few yrs out of it but who wants to throw good $$ into something that is going to need replacing anyway. Average life is 15-20 yrs where I am although it is colder here. 20 is where most people draw the line on spending their repair $$. Once it fails in the middle of the night or during Xmas holidays is the worst time to get quotes and replace it as it is stressful and you got NO time to haggle or shop around.
 

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Discussion Starter #9
No you're 100% right about having to make a shot gun decision when it finally dies, paying too much for something you might not need/want.

My dad's getting older and things don't really seem to phase him as much so i'm looking out for him.

Do you know any good installers in the greater Toronto area Yuri? And what would you recommend on brand for this size home.

Thanks again
 

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I don't really know, had a guy named TKG here awhile back who is in TO but I don't know his biz name. I would stay away from DirectNRG as I don't like their biz practices. Need to do your shopping and check references with his neighbors, people you know/work with etc to find someone who does good work. Most brands work well IF installed properly but there can be larger differences in how quiet they are and how sturdy they are built. Lennox/Carrier/Trane/York is my favs. You get what you pay for price wise. The contractor should do a heat loss calculation to size it properly and show you that on paper. My salesguys have it in their laptop and do it on the job. For elderly people that feel colder as they get older you may want to go with a 2 or 3 stage furnace or Lennox SLP modulating unit as it provides a lot more comfort with its longer more even heat cycles. A mod will feel like hot water baseboard heating and the high end ones are so quiet you can barely hear them run. Like buying a Buick or Caddy instead of the basic Malibu.
 

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Discussion Starter #13
Hey Doc,

Yes there is A/C. I have no idea what the easiest way to check the coil would be. Duct leaks I am unable to determine since the basement is finished.
 

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Well I'll tell you that I clean blower wheels and evaporator coils all the time, makes a huge difference in air flow. You're going to need to be able to check the ducts.
 

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If it is not moving enough air from a dirty AC coil or slowing running fan then it will cycle on/off with the limit control. That will prematurely shorten the life of the heat exchanger and eventually can break the limit control. You may want to get a Pro to check that furnace for safety issues/cracked heat exchanger or popped out rivets that hold it together. I imagine your parents safety is worth spending some $$ on.
 

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As others have said, A/C coil needs checked. Its one of the things that often gets over looked as a cause of poor air flow during the heating season.
 

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Discussion Starter #17
Ok I would like to try and clean the 'A' coil but there is no access so where do I make the opening at the front of the plenum?

Thanks guys
 

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At best, if your lucky and careful, you'll be able to pull the Plenum apart, maybe by expanding a Pittsburgh joint. Slide the acoil off the furnace, should the lineset permit, on to some saw horses. This would give 100% access to clean the crap out of it.
 

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Discussion Starter #20
I was finally able to take a few pictures of the unit and here they are. I took some tape off from around the a coil lines and drain and it seems there's more to just cutting a hole. There seems to be a plenum inside a plenum???
 

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