Gas and Oil Home Heating Furnaces - Hot air furnace filter?

Hi,
I recently bought a home with an oil fired hot air furnace,maybe 15 yrs old?.The air filter was very dirty,so I bought a new one.Ace Hardware (blue about $2)This is a rental home.
The size on the one in the furnace said 20x20x1.
I bought the same size,but found it awful tight.It acualy buckled a little when I put it in?Do manufacures vary in size,as the other one seem to fit better.
Also the filter that was in there had the air flow arrow pointing down towards the cellar floor.I put the new one in the same way,I believe this is correct,am I right.Thanks;)

On a one inch filter it won't make that big a difference. Use your eyes...is the air flowing through the filter in the direction of the arrow? If it isn't, flip it! The tight fit is a pain in the neck, but you might find that someone put a screw into the filter tray that is binding up the works. We usually use the fiberglass throw aways for heat and pleated air filters for cooling, the pleats sometimes slow down the air flow a little too much. Its hit or miss with this, unless you measure the temperature rise. If the furnace goes off on high temp, go to the fiberglass. Some furnaces do well with either. If dust is a concern, you can get a spray that is a light mineral oil, I think, and this helps catch more dust. A neat little trick for home owners, to freshen up the house, is put an air freshner on the return grille, or on the air filter, it gets to all the rooms instantly.

Hi,
I wrote recently about changing a filter in my a hot air oil fired furnace in my rental home.
My tennant called tonight,and said the furnace has been making a banging type noise when it starts and shuts off.She says its since I recently changed the filter?She said it wakes her up at night...
I went to take a look at it,I wanted to be sure the filter was installed correctly.It appears fine.I did replace it with another filter,just to see if it made a differance.I put in a pleated paper
filter instead of the cheap blue filters.
I had her start the furnace,and the noise sounds like its in the sheetmetal chamber on top of the furnace.It makes a expanding type pop when the blower turns on and off.After it is quite and heats fine.
The filter that was originally in there was a cheap blue type,but very,very clogged.
I assume the noise is from the change in the volume of air now being able to be pulled thru the filter???
Does this sound like this to you?
I assume its nothing to worry about,or is there anything I can do to stop the popping,expanding noise in the sheetmetal chamber?
Thanks,Iam new to hot air furnaces.We live in Mass.:rolleyes:

This is a common problem seen on alot of warm air systems. Most of the time I find dampers are being blocked by the couch on top of them , book cases placed over themect. Start looking for restrictions to each of the registars and make sure they are full open. If your in the basement count the total and account for each, They will also have a damper blade adjuster on the main duct branch. Try that to start with.......

Hi,
So you think there is a good chance something like furniture is blocking a register?I haven't thought of that,that will cause the sheetmetal poping noise at start-up?
Also would it be more noticable with a clean filter in it?This is when it seemed to start she said?thanks:rolleyes:

Good sheetmetal work will have cross breaks in it. Instead of a smooth flat surface you will see like an X pattern crease in it. What you can do , if the afore mentioned doesn't resolve the popping, is to install a reinforsing piece of metal in the location it pops at. It may be only one or two places. Try first seeing if a restriction is the cause first. Would a new air filter make this start, yes! Should you leave the dirty filter in, no. A lack of air flow across the coil may destroy the compressor on a call for cooling. The heat will bounce off the high limit and may overheat the unit altogether. ;)