Missing a piece?

[nwredsox]

I bought a house with heatilator gas novus direct top vent lp fireplace which was all taken apart because the morons tried to fix it (bad thermo). I have since repaired and cleaned the unit. However inside the firebox at the top where the vent goes out is 4 screw holes around where the vent pipe is. So the hot air in the box has a straight shot to the vent and out of the house. It seems to me there should be something there to adjust or limit the airflow allowing the box to get hotter. There is more heat going outside than what the unit is outputting with the fan on. The unit appears to be working great otherwise. Nice flames but I think they are on the orange side. Any help would be appreciated.
Mike

 

[DAKSY]

Those four holes are there for the air flow restrictor. It is more for controlling (restricting) the incoming air than for keeping heat in the firebox. Top vent units with extremely high vertical venting require the restrictor to slow the combustion airflow INTO the firebox, as it agitates the pilot flame & can cause the pilot to fluctuate at thermocouple contact point. This can cause the pilot & gas flow to shut off. I suppose you can contact your Heatilator/Heat N Glo dealer to see if he has a restrictor lying around. Every unit ships with one & most are probably just thrown away if they're not used. Also you can check the manual package to see if it was left in the bag. The restrictor will be a donut-shaped piece of steel, about 1/16" thick & about 7 - 8" in diameter with about a 3" diameter hole thru it... Installing it probably won't give you any more heat, but I doubt it'll hurt the unit...