Marley MD26 DPST Snap-Action L...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$70.90
Marley MD26 DPST Snap-Action Line Voltage Thermostat

Marley MD26 DPST Snap-Action Line Voltage Thermostat

(No reviews yet) Write a Review

Model: MD26

In Stock (leaves warehouse same day if ordered before 3pm ET)

$70.90
Adding to cart… The item has been added
Free Shipping on orders over $199
We price match and offer bulk discounts! Click Add to Quote. It's quick and easy.
✨
Earn points with this purchase! You can redeem points for giftcards, iPads, XBox's and more. View Rewards
Free Keying on all locks
You may also like

Marley MD26 DPST Snap-Action Line Voltage Thermostat

The Marley MD26 (QMKMD26) is a DPST (double-pole single-throw) snap-action line voltage thermostat control built for direct wiring into line-voltage electric heating circuits. Engineered with a positive snap-action switching mechanism, this control is designed as a compatible replacement thermostat for Marley and Qmark electric baseboard, wall, and unit heaters that call for a line-voltage, double-pole control. Because it operates directly on line voltage, no external low-voltage transformer or relay is required, simplifying installation and reducing potential points of failure in the heating circuit. Its double-pole configuration makes it well suited to servicing line-voltage electric heating equipment where both supply legs must be interrupted together for safe, complete circuit disconnection during off-cycles or servicing.

Key Features

  • DPST Switching: Double-pole single-throw contacts switch both hot legs of a line-voltage heating circuit together for complete, simultaneous disconnection of the load.
  • Snap-Action Mechanism: A quick make-and-break snap-action design delivers crisp, positive contact transitions instead of slow mechanical drag, helping reduce contact arcing and wear over repeated cycling.
  • Line Voltage Control: Rated for direct line-voltage operation, allowing the thermostat to control the heater load without an intermediate low-voltage relay stage.
  • Model MD26 / QMKMD26: Identified by its manufacturer designator QMKMD26, this control is intended as a direct-fit replacement part for the corresponding Marley/Qmark heater thermostat position.
  • Simplified Wiring: Line-voltage, double-pole operation keeps the control circuit straightforward for electricians servicing existing electric heating installations.
  • Field Replacement Fit: Sized and configured to drop into the thermostat position on compatible Marley/Qmark heater models without modifying the existing line-voltage wiring layout.

Technical Specifications

  • Refer to manufacturer documentation for complete technical specifications.

Typical Applications

  • Electric Baseboard Heater Thermostat Replacement
  • Electric Wall Heater Control Circuits
  • Unit Heater Line-Voltage Temperature Control
  • Commercial and Residential Electric Heating Systems
  • Service and Repair of Existing Marley/Qmark Heaters

Why Marley?

Marley (Qmark) is a long-established name in electric comfort heating equipment, and its thermostat controls are built to keep that equipment running reliably in the field. The DPST snap-action design of the MD26/QMKMD26 gives contractors and facility technicians a straightforward, code-appropriate way to restore accurate line-voltage temperature control to an existing electric heater without reworking the surrounding circuit. For electrical contractors and facility maintenance teams stocking parts for heater service calls, the MD26/QMKMD26 offers a dependable, purpose-built replacement rather than an improvised substitute.

Manufacturer Resources

QMark Digital Catalog 2025

Product Specs

Product Type:
Thermostat
Configuration:
2-Pole
Department:
Electrical
Product Group:
Heating
list_batch:
MAR-20260910
Product Subgroup:
Thermostats

Marley MD26 – Frequently Asked Questions

1) Does the Marley MD26 thermostat need a transformer or relay to control an electric heater?
No. The MD26 (QMKMD26) is a line voltage control, so it wires directly into the heater's line-voltage circuit and switches the load itself. No low-voltage transformer and no intermediate relay stage are involved, which is why it drops into existing electric heat wiring without rework.
2) Will the MD26 break both hot legs of a 240V baseboard heater circuit?
Yes. The MD26 is a DPST (double-pole single-throw) control, a 2-pole configuration, so both supply legs open together at the end of a heat cycle. That matters on 240V electric heat where a single-pole stat leaves one leg energized at the heater during off cycles and during service.
3) Is the Marley MD26 a direct replacement for the thermostat in my Qmark heater?
It is built as a drop-in replacement for the thermostat position in Marley and Qmark electric baseboard, wall, and unit heaters that use a line-voltage double-pole control. It is sized and configured to fit that position without changing the existing line-voltage wiring layout. If the heater you are servicing uses a single-pole or low-voltage stat instead, the MD26 is not the matching part.
4) What part number do I order for the MD26, and is QMKMD26 the same thing?
Same control. Marley catalogues it as MD26, and QMKMD26 is the manufacturer designator for the same part. Order by MD26 and you are getting the QMKMD26 double-pole line voltage thermostat.
5) What is snap-action switching and does it matter on a heater thermostat?
Snap-action means the contacts make and break quickly rather than dragging slowly across as the bimetal moves. On the MD26 that quick transition cuts down arcing and contact wear over repeated heating cycles, which is the usual failure mode on a line-voltage stat that is switching a resistive heater load every day.
6) Can an electrician use the MD26 on commercial electric heat, not just residential baseboard?
Yes. Typical applications for the MD26 run across commercial and residential electric heating: baseboard thermostat replacement, electric wall heater control circuits, and unit heater line-voltage temperature control. Facility maintenance teams commonly stock it for Marley and Qmark heater service calls.
How fast can I get the Marley MD26 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Marley MD26 come with a warranty?
Absolutely. The Marley MD26 is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Marley MD26?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
Why buy the Marley MD26 from ZenSupply?
ZenSupply makes it easy to get the commercial door hardware you need—fast shipping, expert support, and rewards on every order. Our team is always ready to help you choose the right product for your project.
!