< or > 90% efficiency oil furnace?

[paulmars]

I just bought a new thermostat for my central oil HVAC unit. Honeywell TH4110D. I can set it for oil heater <90% efficiency or >90% efficiency. I'm not sure which to set it at. I am hoping that my unit is not exactly 90%, cuz then I'm screwed. Bryant model 58cma105-12 installed in year 2001. Bryant wont help me. they insist that i pay a service tech to come here and tell me. That ain't happening.

Also, compressor cycle rate setting 3 is recommended for most compressors. I hope that is what I have.

Your thoughts?

tks,
pa

 

[semipro]

I am hoping that my unit is not exactly 90%, cuz then I'm screwed.

That's funny.
So the <90 >90 setting pertains to cycles per hour. A year 2001 Bryant - hard to imagine its better than 90% efficient. I suggest choose the <90 and see how it works.

Edit: interesting discussion here on heating cycles: http://www.diychatroom.com/f17/heating-cycles-per-hour-options-gas-oil-furnaces-107564/

 

[EatenByLimestone]

There isn't a tag on the side listing efficiency?

If not, how is it vented? If not power vented, I bet you're about 85% efficiency. Enough heat has to stay in the exhaust to run the chimney.