A recommendation has been made that I "need" a float switch installed on my electric furnace upstairs. Problems could result from water collecting/overflowing in the drain pan. Is this switch really necessary?. seems new systems would come with this installed already. Would suspect that the float switches and any related electronic add-ons would also be subject to failure and would compound the risk already present. Appreciate your response in advance.

Yes in many areas of the country an additional overflow drain is also necessary besides the float switch. Why would anyone in there right mind worry about a cheap float switch when possible 100's or 1000's of dollars worth of damage can be done by a overflow of condensate.

This is a longshot but I will ask if you have a condensate pump by the furnace that pumps away the condensate in the summer? If so it has a float switch in it but that should only affect your air conditioning and not the furnace.

I have not heard of a float switch in nay electric furnace, so if you get an answer to your question I will be interested in that also.

hvac1000's post is right on. AC units and heat pumps create water. Attic installed systems usually get a second drain pan and a switch.

This one is typical. ComfortGurus.com: Diversitech Wagner WS-1 - Wet Switch Flood Detector It's not a float switch.

Where I live we use the double pan system but we do not us a pump only a second drain that runs to some obvious place so that you will see the wet spot if water happens to come out of it. That way you know that you first drain pan is stopped up.

Different areas different rules

A pump sometimes isn't necessary, but the second drain pain+switch saves a lot of costly repairs.