Fan has a switch for winter and summer. Is it up or down for summer?

replace the switch and leave it work as it was designed to

If its a ceiling fan then you need to operate the switch on side of fan housing to winter, this reverses motor operation and makes fan "blow" towards ceiling. Summer mode fan "blows" down.

There is a "Klixon" switch mounted to the heat chamber that is stuck closed. It will be wired in series directly into the motor wires

The typical 'summer/winter' switch is an added switch associated with OLD heating systems back in the 50's and 60's before central air conditioning became common in homes. I doubt that your new furnace had one installed because you can accomplish the same thing by switching the fan on at the thermostat sub-base. That is, of course, providing you have a subbase with 'fan-on-auto' on it.

Clockwise on high for Summer. Counter Clockwise on slowest speed for Winter, to get the heat off the ceiling. A good way to remember which direction it should go from season to season , is by the directional switch on the side of the fan.. Switch Up for Winter. Switch Down for Summer.

Hope this helped you. Please let me know. Thanks.

I'm not sure that the manufacturers are consistent on which way to mount the switch (many are mounted sideways).

For summer, you want the wind to blow down on you. Hold a strip of paper in your hand and see which way it goes.

For winter, you want the wind to blow upwards. This will push against the ceiling, forcing the warm air to circulate down to the floor level.

In winter you want the fan blowing up forcing the warm are from above down. It will **** the cooler are at the floor up and force the warm are at the ceiling down.

Although there are those who would say otherwise, it really doesn't matter much which way the fan turns regarding summer or winter. It does matter regarding whether you want air blown directly down upon you or sucked up past you toward the ceiling. Some would say that the fan should blow down in the winter, since hot air rises and the fan would blow it back down, but if you think about it, if the fan is blowing air toward the ceiling, the hot air up there has to go somewhere, like down when it reaches the walls. It is, once again, really a matter of what makes you comfortable in summer or winter.
Hope this helps.

Winter mode pulls air up, summer pushes down (so you can feel it better) -Carl

I winter it blows up to catch the warm air from the ceiling and bring it down. In summer it blows down to cool you off by evaporation.