Whistling Fisher Insert

[vt-new-fp]

My Fisher FP insert whistles when the doors are closed. It started last year and I just got used to it, but had someone over recently who noted that it was annoying. Is it anything to worry about? It changes pitch and speed with the outdoor wind. I have the stainless steel liner (6 years old) inspected and cleaned every year before burning season. Wood burns fine, no excessive creosote build up. I have tried a bunch of things over the years to fiddle around with the stove (door sealer, no door sealer, how much to open the dials, etc - never figured out how to make that baflle), but now I'm wondering if I should do something about the whistling? It also whistles in the summer when it's windy out, when not burning.

 

[coaly]

Leak into liner where connected to Insert?

The hot rising exhaust gases moving up flue creates a low pressure area that atmospheric air pressure pushes into. It should only be able to push into air intakes, but any leaks onto the venting system allows the higher pressure to leak in.

Wind also creates a low pressure area or vacuum in chimney flue, allowing leakage into liner at bottom.

I would remove the top cover plate and using a shaken out match or incense stick you will probably see smoke drift towards the opening as smoke is drawn into it.

This is also done around door seals. In your case, only cleaning the back of doors where they contact iron door sealing channel and the channel iron itself with a wire wheel normally makes the contact surface smooth enough to seal. (Glass door models use gasket material)

 

[vt-new-fp]

Leak into liner where connected to Insert?

The hot rising exhaust gases moving up flue creates a low pressure area that atmospheric air pressure pushes into. It should only be able to push into air intakes, but any leaks onto the venting system allows the higher pressure to leak in.

Wind also creates a low pressure area or vacuum in chimney flue, allowing leakage into liner at bottom.

I would remove the top cover plate and using a shaken out match or incense stick you will probably see smoke drift towards the opening as smoke is drawn into it.

This is also done around door seals. In your case, only cleaning the back of doors where they contact iron door sealing channel and the channel iron itself with a wire wheel normally makes the contact surface smooth enough to seal. (Glass door models use gasket material)

Thanks, Coaly! I cleaned off the groove in the doors with a wire brush and that decreased the whistle. I have a sense that it has something to do with the right-hand door. With the doors both open there is no whistle, and with the left door closed, no whistle. I'm going to monkey around with the right door before I try to get into where the liner meets the insert because that's a big undertaking.

 

[coaly]

When you open a door, the velocity of the leak would slow or stop leaking in through the opening making noise.

Think of the chimney as a big vacuum cleaner. With air intake and everything closed, no air should leak in, vacuum increases. A slight leak allows air to rush into the crack. Which is what you hear. Now open the door and the air takes the path of least resistance through the door opening. It no longer leaks in through a crack somewhere because all the air is moving in through the door opening.