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Small rectangular HVAC thermostat with metal probe and terminal connectors

SUPCO

SUPCO SHL509 Thermostat 210-240°F 2-51/64in SPST

SKU CH-JQQE-8Y3VJ

A plenum thermostat with a 210 to 240°F range, 3 1/8-inch insertion length, and SPST switching

  • SPST switch provides reliable on/off control
  • 210 to 240 °F range suits high-limit safety
  • 2-51/64 in depth fits standard plenums
  • 30 °F differential prevents short-cycling
  • Rated 1.5 A to 15 A for varied loads

HVAC Plenum Thermostat 210-240°F

The SUPCO SHL509 is a single-pole single-throw plenum thermostat designed for HVAC control applications. It opens on temperature rise within a 210 to 240 degrees Fahrenheit range. The 3 1/8 inch element insertion length suits standard plenum mounting.

Sustained Load Switching Behaviour

The differential is 30 degrees Fahrenheit between cut-out and cut-in, preventing rapid cycling during continuous operation. It carries three separate current ratings: 15 A, 10 A and 3 A at the upper end, plus 1.5 A at the lower end. This spread covers sustained inductive and resistive loads without nuisance trips.

Compact Body and Terminal Layout

Overall depth measures 2 51/64 inches with a width of 1 7/8 inches, allowing installation in tight plenums. SPST action means two terminals complete the circuit cleanly for straightforward wiring. No extra poles or auxiliary contacts are present, keeping daily service simple.

How it compares

Measured against everything we stock in Heating & Cooling Controllers, at today’s prices. Recalculated every night.

Price $9.99
Cheaper than about 90% of the 1,762 comparable items (median $45.99).

Specifications

Product
Brand nameSUPCO

Questions about this item

Does the 3 A / 1.5 A / 15 A / 10 A rating on the SHL509 mean it runs hot when the furnace cycles all day?

The control is rated for 15 A at the lower voltage and 10 A at the higher voltage; normal plenum mounting keeps temperature rise within design limits during continuous cycling.

What wiring or mounting hardware must I already have to install this 2-51/64 in. deep plenum thermostat?

You need a plenum opening that accepts a 3 1/8 in. insertion length, 1 7/8 in. width and 2 51/64 in. depth, plus supply wires sized for the 15 A / 10 A SPST contacts.

Will the 30 °F differential on the SHL509 work with an older furnace that expects a tighter swing?

The 30 °F differential is fixed; it will widen the on/off swing compared with controls that have a smaller differential, so verify the original spec before replacing.

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