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Author Topic: Suburban SF-35  (Read 271 times)


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  • Posts: 60
Suburban SF-35
« on: January 01, 2018, 08:10:38 PM »
I've sent the last 4 hours trying to figure this out....any help would be greatly appreciated.

When I pulled the above furnace out about 3 months ago I cut the wires off leaving wire connectors attached to the furnace wires.
Black + to Red
White - to Yellow
Blue (with no markings) to the W wire from the thermostat.
There is nothing to connect to the Blue ++++ that is on the switched leg.

It is possible that I pulled something out but I cannot find any other wires from the thermostat.

What else would the Blue ++++ connect to?

Everything was running before but the trailer is used so things could have been changed around before.

Here's a link to the manual

Wiring diagram is Fig.25 on  Pg.35

Thank You.
35' 5th


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  • Posts: 1022
Re: Suburban SF-35
« Reply #1 on: January 01, 2018, 11:09:29 PM »
If I recall correctly there should be 2 blue wires, when they are connected together through a switch or a thermostat the heat comes on.
2002 Safari Trek 2830


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  • Posts: 60
Re: Suburban SF-35
« Reply #2 on: January 02, 2018, 12:27:07 PM »
Figured it out...... :)

The Blue+++ wire is used to power a thermostat.

In this case the thermostat receives power from somewhere else so the blue++++ wire is not used.

The only issue with this is that the On/Off switch on the furnace cannot be used so the only way to have the furnace go thought the shut down/ cooling cycle is by using the thermostat. 
35' 5th