Metal Surround/Cement board? Mark 123 Heatilator

[dcva]

I purchased my home and with it came a converted gas log set in an old 80's wood burning Mark 123 Heatilator 3138EP I recently replaced the gas logs and burner due to a slight gas leak in the pilot valve on and off switch. My question is the following. Can I install cement board over the black metal surround and attach marble? Since this is no longer a wood burning insert and the old heatilator vents are disconnected am i able to cover the bottom vent? It leaks so much cold air from the outside.

 

[begreen]

No, they can not be covered.

 

[dcva]

No, they can not be covered.

Is there a reason or code issues? The metal doesn’t get hot. I understand not covering the bottom vent but the metal sides?

 

[begreen]

Blocking the vents violates the UL certification for the fireplace and may affect the cooling or clearances in other parts of the fireplace besides just the face. Also, there is no telling what the next homeowner will want to do with the fireplace. If they revert it back to woodburning it could be very dangerous. The manual specifically says, Don't Block Off the Vents.

 

[bholler]

Those vents are also required even if it is only gas logs in there

 

[dcva]

Blocking the vents violates the UL certification for the fireplace and may affect the cooling or clearances in other parts of the fireplace besides just the face. Also, there is no telling what the next homeowner will want to do with the fireplace. If they revert it back to woodburning it could be very dangerous. The manual specifically says, Don't Block Off the Vents.
View attachment 281677

 

[dcva]

So on page 15 how do you interpret the “Facing Material” section? I’m reading this as if I can cover the top and side as long as the dampers chain access panels are not covered or the bottom
Vent. https://downloads.hearthnhome.com/installManuals/3138EP.PDF

 

[dcva]

And to be clear I’m talking about putting marble highlighted by the red lines. Not blocking any vents. The diagram in the install guide make it seem like that is okay.

 

[bholler]

And to be clear I’m talking about putting marble highlighted by the red lines. Not blocking any vents. The diagram in the install guide make it seem like that is okay.

View attachment 281682

Follow the instructions on page 16 of the manual for facing.