Vermont Castings Radiance - no Restrictor Plate

[jennk8r]

Hi There
I have acquired an older Vermont Castings unit and we are ready for install however there is no restrictor plate for the unit and it is no longer available. I was told that as long as we have 2 ninety degree elbows in our venting we can do without the restrictor plate. Thoughts??

 

[DAKSY]

That is probably correct. The restrictor plates are mostly used for tall vertical runs to keep the incoming combustion air from agitating the pilot flame/thermocouple interface.
IIRC, each elbow reduces vent height by 3 feet.
If you have a problem, maybe someone in here with a Radiance can give you the measurements of their restrictor plate.
Generally speaking they are simply flat plates that block an air hole...

 

[Tech Guru]

If it is an older Direct Vent unit (models RDVOD or RDV40), the restrictor plate was more of a ring (like a big washer) that would get dropped into the flue collar before the Vent starter pipe gets installed. If memory serves, the opening for the Radiance was approximately 2 1/2". And as DAKSY points out, they were only needed for vertically vented units with more than about 14 feet of total height, and the vent height at which it was required increased with lateral offsets. They were never required if the unit was vented with a horizontal termination.