Suburban 525028 Sail Switch – Furnace Low Air Flow Switch (Replaces 233100, NT Series)

Product Overview

The Suburban 525028 Sail Switch (formerly part 233100) is a critical safety component designed for Suburban NT series RV furnaces. This low air flow switch ensures that the blower is moving sufficient air before allowing the furnace to ignite, preventing unsafe operation.

If your furnace blower runs but the burner will not ignite, the sail switch is one of the most common failure points. Replacing a faulty sail switch can quickly restore proper furnace operation and reliable heat.

Key Features

• Replaces Suburban part 233100 (updated part number 525028)
• Designed for Suburban NT series furnaces
• Low air flow safety switch (sail switch)
• Ensures proper airflow before ignition
• Helps prevent ignition failure and unsafe operation
• Common fix for “blower runs but no heat” issues
• Direct OEM replacement for proper fit and function
• Durable construction for long service life

Specifications

• Part Number: 525028
• Replaces: 233100
• Product Type: Sail switch / low air flow switch
• Function: Airflow verification before ignition
• Application: Suburban NT series furnaces

Compatible Furnace Models

Suburban NT Series

• NT-12S
• NT-16S
• NT-20S
• NT-12SE
• NT-16SE
• NT-20SE
• NT-16SQ
• NT-20SQ
• NT-16SEQ
• NT-20SEQ

Important Compatibility Note

• Designed specifically for Suburban NT series furnaces
• Verify your furnace model before ordering
• Not compatible with SF series furnaces

When Should You Replace the Sail Switch?

You may need the 525028 sail switch if your furnace:

• Blower fan runs but the burner will not ignite
• Has no spark or ignition after startup
• Cycles without producing heat
• Works intermittently
• Has debris or dust buildup affecting airflow

The sail switch is one of the most commonly replaced furnace components.

Why This Part Matters

• Ensures safe furnace operation by verifying airflow
• Prevents ignition when airflow is insufficient
• Restores proper furnace startup sequence
• Simple and cost-effective repair for common furnace issues

FAQ

What part does this replace?
This replaces Suburban part 233100.

What does a sail switch do?
It verifies that the blower is moving air before allowing ignition.

Is this a common failure part?
Yes, it is one of the most common causes of “blower runs but no heat”.

Will this fit SF series furnaces?
No, this switch is designed for NT series furnaces only.

Is installation difficult?
Installation is typically straightforward, but ensure power is disconnected before servicing.