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Suburban SF-30 to SF-35 Furnace Upgrade

Cholla_Bob
Explorer
Explorer
Can I replace a SF-30 30000 BTU Suburban furnace with a SF-35 35000 BTU unit?

My SF-30 shook extremely last night and shutdown. Now cool air blows with no heat. Since its 5 years old, I am replacing and will repair this unit as a backup. As I already have 4 interior cabin vents, can I upgrade to a SF-35? The unit is running on a 20 amp fuse and this seems like a better option for our 650 square foot space. The Suburban installation guide specs (except for vent specs) are the same for both units. Thanks. John
5 REPLIES 5

ScottG
Nomad
Nomad
We only have 3 with our 35 and most of the time I shut off the bedroom vent.
You should have no problems at all.

Cholla_Bob
Explorer
Explorer
Good to hear. Suburban rep could not answer this question: I really appreciate the info Thanks!!!!

DrewE
Explorer II
Explorer II
Propane usage should not change dramatically for the same heating conditions. The rate of consumption when the furnace is working would be about a sixth again greater, but since it produces more heat it will run for a shorter period of time and the two theoretically cancel out.

Cholla_Bob
Explorer
Explorer
Thanks for the info Old-Biscuit! I already have 4 vents with the SF-30, so it looks like a direct replacement for the SF-35. I would imagine the propane increase would be 1/5th more. Appreciate that Suburban manual! John

Old-Biscuit
Explorer III
Explorer III
Suburban Furnaces Service Manual

SF-30 minimum vents is 3 (4")
SF-35 minimum vents is 4 (4")
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