Enviro Meridian makes a Whistling Noise

When are you getting the noise, after the room air fan comes on or before?
Do you have an outside air feed(kit) installed? If not, you might have something in the air feed tube, like a piece of paper. Also, have you taken the three back panels behind the firebrick metal panel off and cleaned behind there?

There are three panels back there. Take out the babble, remove all the screws from the round access hoes ans fire brick pansl. There is also a round rod with a screw at the upper center of the three panels that holds them in place by going through a hole in each of the two side panels. If you put a small vaccuum hose back there, you can get out alot of ash.

You should also take off the combustion fan and clean out behind it once a year ( this is the fan on the left hand side of the stove ,looking at it from the front ). Ash builds up there and will interfere with the vanes on the fan if alot builds up. The manual doesn't tell you these procedures for some reason. I got a hold of a tech at Sherwood Industries who thought I was a dealer and he gave me the info. When he realized I was an owner, he shut up fast and told me to contact a dealer. I guess they want the dealears to have some job security.

One last thing, make sure you have a replacement gasket for the combustion fan. It will rip when you take the fan off. Make sure you tag the connecters on the wires you unplug, so that you don't mix them up.