Suburban 525035 Furnace Limit Switch – SF-42 / SF-42F / SDH-2542

Product Description

The Suburban 525035 Furnace Limit Switch is a critical safety component designed to regulate internal furnace temperature and prevent overheating. This single limit switch opens at 195°F and resets at 155°F, helping protect your RV furnace from damage while maintaining proper operation.

Designed as an OEM replacement, this switch fits select Suburban SF-42, SF-42F, and SDH-2542 furnaces. A failed limit switch can cause your furnace to shut down prematurely, cycle repeatedly, or fail to produce consistent heat—making this a key replacement part for restoring performance.

Key Features & Benefits

• OEM Suburban Part #525035
• Opens at 195°F, closes at 155°F
• Prevents overheating and internal damage
• Restores proper furnace cycling and operation
• Durable, direct-fit replacement

Compatibility

Fits the following Suburban furnace models:

• SF-42
• SF-42F
  • Applies to units below serial number 921403896
  • Applies to units above serial number 921403895
• SDH-2542

Always verify model and serial number before ordering.

Common Problems This Part Fixes

• Furnace shuts off too quickly
• Furnace overheats or trips safety limit
• Burner cycles on and off repeatedly
• Inconsistent or no heat output

What’s Included

• (1) Suburban 525035 Furnace Limit Switch (Single)

Installation Notes

• Disconnect power before installation
• Replace in the same mounting position as the original switch
• Verify proper wiring connections
• Professional installation recommended if unsure

FAQs

What does a furnace limit switch do?
It monitors internal temperature and shuts the furnace down if it overheats to prevent damage.

How do I know if my limit switch is bad?
Common signs include short cycling, overheating shutdowns, or inconsistent heat.

Is this compatible with all SF-42 furnaces?
It fits specific serial number ranges—confirm your unit before purchasing.

Can I install this myself?
Yes, if you are comfortable with basic electrical components; otherwise, professional installation is recommended.