my new clydesdale has been making a buzzing noise that is coming from the sheet metal that goes below the blower control. not sure if this is your issue but my dealer is ordering me the vibration dampener to resolve. the forum doesn't allow attaching .pdf's but i've pasted the text from it below.
©Hearthstone Quality Home Heating Products, Inc.
www.hearthstonestoves.com
R: 4 - 3/10/2010
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Technical Bulletin #122
Product Information
Clydesdale 8491 Air Shroud Vibration Dampener Install
Publication Date: 3/10/2010
Re: Clydesdale Model 8491
Starting Serial Number: 005000
Starting Production Date: June 2009
When the insert is in use, and up to temperature, blower operation can cause a resonance, or vibration in the
bottom air shroud sheet steel. This vibration can cause a loud hum that can change with temperature and
blower speed.
The high temperature silicon vibration dampener is designed to reduce any vibration of the bottom sheet steel
and eliminate the hum. The vibration dampener is easily installed without removing the insert from the fireplace.
Design changes to the bottom air shroud steel will eliminate resonance, or vibration issues in future production
runs.
The part number for the Vibration Dampener Kit is 3000-005
Procedure:
1. Remove the ash lip cover by loosening the two set screws. Take care to avoid chipping enameled finishes.
2. Place the vibration dampener to the left of the air control as shown. Compress and tilt the dampener under
the insert wedging it between the cast bottom of the insert and the bottom steel air shroud.
3. Push the vibration dampener completely under the insert as shown below. Ensure the dampener does not
interfere with the air control operation.
4. Re-install the ash lip cover.
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