RSF Onyx Back Refractory Brick (FR-11.3.N)

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USD $61.31

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SKU: FR-11.3.N Categories: , , ,

Product Description

This is an official OEM RSF and RSF Energy Replacement part. This replacement refractory brick is a new RSF factory part new in original packaging.

RSF Part Number: 11.3.N (same as FR-11.3.N and replaces old part numbers R4203 & A1240-6)

Part Description: RSF Onyx Back Refractory Brick (each) 2 Required.  This is the price for each individual piece, if you want to replace both, you will need to order two.

Applicable Models:

  • RSF Energy Onyx
  • RSF Onyx
  • RSF Onyx AP

Purpose: The firebricks are designed to protect the fireplace from warping.  They also keep the heat in the fire to ensure a cleaner burn.

Installation tips:  Make sure that you clean all the ashes out of the firebox.  Use a vacuum (a shop vac with a drywall filter is best) to clean all the ashes out.

Other Notes: This is the price for each individual piece, if you want to replace both, you will need to order two. Do not use a household vacuum and make certain that there are no embers in the ashes before vacuuming.  If you vacuum embers, you will risk having a fire in your vacuum.


This genuine RSF Onyx replacement brick is in stock ready to ship.

Shipping Dimensions

Weight 25 lbs
Dimensions 25 × 25 × 15 in

Replacement parts come with a 90 day warranty unless otherwise stated.

All Gas or Pellet components must be installed by a licensed technician.
All Gas or Pellet component warranty claims must include installation receipt to qualify for warranty.

Please contact Online Store Support with any warranty questions.


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