White Rodgers 535 Limit Switch Replacement

[Wrex]

My Mueller furnace's limit switch has just bit the dust and its time for replacement due to erratic operation.

The old switch is a White Rodgers Model 535 that isn't manufactured anymore. It is a combination switch that has both fan and limit functions.

I removed it to check it out and the elements that extend over the bonnet measure 16 inches from the unit to the tip.

I have found a unit that is identical to the old unit.

I have two White Rodgers models for replacement in mind either the:

5A75-5

5A75-12

The 5A75-5 only has a 9 inch element which isn't as long as the old switches elements were.

The 5A75-12 has the same 9 inch element but has a 60 inch capillary so it gives me the extra reach I need.

This is the one I am really considering but I have one concern. Isn't the 60 inches a bit extreme? Would the extra length effect the reaction time of the switch?

The extra capillary would be coiled if I use the 5A75-12.

Here is a link for a visual between models:

http://www.white-rodgers.com/wrdhom/.../0037-0874.pdf

The 5A75-12 is on the left while the 5A75-5 is on the right.

Thanks for the help in advance.