AIR HANDLER making noise when it shuts off


Old 07-27-16, 03:30 PM
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AIR HANDLER making noise when it shuts off

i have bought this home about 3 years now - this is ranch house
my air handler is in attic

when i moved changed the condenser outside the home, this is 3rd year ( lennox / old refrigerant - no issue here ) however not changed the air handler which is about 13 years old now and it has electronic air filter system (honeywell )

when air handler shuts off, you can hear a hump ( not very loud but you feel it - when it is running it is smooth )

is it due to capacitor ?
how do i check if capacitor needs replacement ??
what are the symptoms of weak capacitor

electronic air filter by honey well - is it a good system to have ?
i have a feeling that this is not working as when i switch it on
indicator does not light up

how do i know my electronic air filter system is working
any alternate or bypass instead of fixing it / replace it with box filter
was suggested at the home show / by hvac contractor

what is typical life of air handler ?
any suggestions for the new one / now i still have new condenser
with old refrigerant

any online part supplier for air conditioners ?

sincerely thank you all for the help / guidance
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Old 07-27-16, 04:23 PM
Join Date: May 2015
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I'll take a shot at answering some of your questions.

A thump on turn off would not be a bad capacitor. Symptoms of a bad capacitor (if your AH even has one) would be trouble starting or loss of power/overheating while running.

A thump on turn off could be bearings wearing out, or something as simple as loose mounting hardware. It could also be duct oil-canning, where a section of duct flexes when air pressure is applied and/or removed and makes a bang/thump sound.

If you haven't cleaned the elements in the air filter in 3 years, I can guarantee they are not working! The elements need to be cleaned every few months or so. It's possible they are so loaded with dirt that they are shorting out the high voltage, which would explain the indicator not being on. Or it may just not be getting power. Elements can be cleaned in the dishwasher. When they are working, the indicator will be on and you will hear an occasional snap or arc sound when a larger dust particle causes an arc.

I like the electronic air cleaners, but some folks worry about the small amount of ozone they generate, or don't like the hassle of cleaning the elements.

Replacing them with a media filter is a reasonable option; they have to be replaced at least once a year. I believe Honeywell makes one that is the exact size as their electronic air filter.

Searching for "Brand and model" parts will find you plenty of online parts suppliers....

Air handlers are pretty simple things so they can last a long time if they are well made in the first place. And they can usually be repaired rather than replaced.
Old 07-28-16, 01:19 PM
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first of all, would like to thank you for your reply

my air handler has capacitor ( rectangular )
also noted to repair the air handler then replace
would like to add that i have hot water boiler for heating
so air handler is used only during summer months when it is hot
so you are looking at 3-4 months of summer only

how to clean dirt / from coil and blower fan ?

also noted as to air cleaner, that power may not be coming thru
anyway to check this ? how do i put back to work ??

i don't mind to clean the elements
which i did it few years back / also this week
however i don't see very little dirt or objects sticking to this elements
as the unit may not be working / as i don's see any indicator light
but i saw a test button in lower part of this filter, so i am going
to put the elements back and try to press the test switch

i have seen someone recommending to keep such capacitor in back up
so how do i know which one to buy for replacement ? i have manual for
air handler ( about 13 years old ) UPG / MODEL F2RP042H06B and
condenser which is new ( 3rd year running ) lenoox / dry charge 13 seer 22 refrigarant
Old 07-28-16, 01:54 PM
Join Date: May 2015
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Here is a link to parts drawing and list for your fan coil unit:

As you can see, your unit uses a 12.5 MFD 370 VAC capacitor. Here is a link to one source: York S1-024-25899-000 12.5MFD 370V Run Capacitor That is according to parts list; not a bad idea to verify by examining the actual capacitor, which should have it's value and voltage rating marked on it.

The best way to check power to the air cleaner would be with an analog multi-meter. It is likely that the cleaner only receives power when the air handler is running since otherwise there is no need for it, so you'll have to turn on the fan coil unit to do testing or troubleshooting on the cleaner.

If you post the model number of the cleaner we can provide additional troubleshooting info.
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