new furnace install, makes buzzing noise

[Ginny28]

I just had a new high efficiency, 2 stage furnace installed. When it runs it makes a buzzing noise. This noise gets real loud when in the second stage. I open the filter door (about 13" by 20") and the air rushes in and the noise goes away. The contractor installed 2 new return vents upstairs, but this didn't help. I plans to install a grill/return in the ductwork right next to the filter. But, I have been advised that this is not a good idea due to being so close to my hot water heater (about 4-5 ft away). My house is small (1100 sq ft upstairs and 780 sq ft in the basement).
How can I tell if the furnace speed is set wrong, if I need more return vents, or what?
I'm concerned because the research I've been doing indicates lack of air return can cause premature mechanical issues.

[how]

Atmospheric HWT's should not have a return air grill anywhere near them or you could end up with CO in the house.
Opening up the fan/filter door on the furnace mimics a larger air return and indicates what the likely problem is but it can also remove the strain on a faulty motor or fan cage so there are other possibilities.
What type of air filter is in the furnace right now? You could try removing it for now to see if the furnace quiets down till the system is corrected.
Put your hand on the return air grills (if ithey are metal) to see if the sound quietens down in case your getting a harmonic vibration.
Do you have A/C and a possibly dirty coil?
Have your contracter do a temp rise measurement on your furnace on both stages and compare them against the furnace spec's.

[Ginny28]

What you say on the return grill makes sense - I'm pretty disappointed it was suggested. I have been really reviewing specs, etc. The air filter is a a Trion Air Purification System, Supreme Right Angle, Merv 8, part # 447380-002. The contractor hooked up an 8 x 24 duct work to the adjustable duct opening. It could have been 10 x 24, so maybe that would help if made bigger? I have tried to find where it says which to use (8 x 24 or 10 x 24), and can't find anything. I'm pretty sure my furnace is 60,000 btus - I don't know if that makes a difference.

I did what you said and took the filter out and listened in stage 1 - yes it quieted down quite a bit.

The AC is new too (one of the reason I upgraded my 1978 model furnace). So, I don't think anything is dirty.

I will ask him on the temp rise measurement.

Any idea on the 8 x 24 or 10 x 24 size of the return duct that goes into the filter box? Thanks so much.

[how]

If you want it quieter then the larger return air is the way to go. Ask him if there is a slower fan speed that can be selected that can still keep the furnace within the recommended temp rise. Is there the need for an additional return air in the home that can also be connected to the filter box to increase your overall available return air? Is the buzzing noise from ducting that is loose and vibrating from the air movement which could be secured properly?