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Just had my Smith series 8/ 5 section converted to gas, using a Carlin ez gas burner. It was shipped with a .332 orifice and "A" diffuser. The gentleman doing the install said he didn't believe it needed to be fired that high, and was going to fire it at 150 kbtu with a 9/32 orifice. I have no problem with that, the house has a heat loss of around 100 kbtus. His CO2 and O2 readings are in range. The unit is operating between 81 and 82% efficiency.My only concern is, I don't think he changed to a "B" diffuser as spec'd by Carlin for a 9/32 orifice. Any concerns? Am I leaving some efficiency on the table with this setup?