What are the specs for this Door Switch?

The correct replacement for Goodman model GMTH045-3B — B1370820 is this exact part. It is the factory-specified replacement with exact OEM specifications. Using a part with different specifications can cause equipment damage or void your warranty. You can verify this by checking the data plate on your Goodman equipment which lists the model number GMTH045-3B — B1370820.

What symptoms indicate I need a new door switch?

Common symptoms that indicate you need a new door switch include unusual noises, intermittent operation, complete failure to operate, or visible damage. For specific diagnostic guidance, visit nationalhvacparts.com/pages/hvac-diagnostic.

Is this door switch compatible with Bryant or Payne systems too?

Many Goodman parts are cross-compatible with Bryant and Payne systems since all three brands are manufactured by Carrier Global Corporation. The same physical part is often used across multiple brand labels with different model numbers. To verify cross-compatibility, check your Bryant or Payne equipment service manual for cross-compatible part numbers, or contact info@nationalhvacparts.com with your model number for confirmation.

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Goodman

OEM Goodman Blower Door Safety Switch w/ Wires for GMTH045-3B — B1370820

Name: OEM Goodman Blower Door Safety Switch w/ Wires for GMTH045-3B — B1370820
Brand: Goodman
SKU: GOODMAN-12531
Price: 40.95 USD
Availability: InStock

SKU: GOODMAN-12531 Brand: Goodman

$40.95 $53.95

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The Goodman B1370820 Blower Door Safety Switch is a genuine OEM interlock supplied with factory pre-attached wire leads, designed for the GMTH045-3B gas furnace and related Goodman/Amana models. This normally-open switch closes only when the blower access panel is fully installed, cutting all power to the furnace whenever the door is removed. It is a required safety device — if your furnace is completely dead with no control-board LED, a stuck or broken door switch is a frequent culprit.

Specifications

Part Number: B1370820
Type: Blower compartment door interlock switch
Configuration: Normally open, closes when panel is seated
Wiring: Includes OEM pre-wired leads with terminals
Fits: Goodman GMTH045-3B and related furnaces
Brand: Goodman (OEM)

OEM vs. Generic

This assembly ships with the correct lead length, connectors, and plunger geometry so it seats against your furnace's door tab exactly as designed. Generic switches often require splicing and may not trip reliably with the panel closed, defeating the interlock. The pre-wired OEM part removes guesswork and keeps the safety function intact.

Installation Difficulty

Easy (2/5). Mounts with one or two screws; plug the leads onto the existing harness or splice per the wiring diagram. Disconnect power first, then verify the furnace only energizes with the door fully installed.

Shipping Information

Orders placed before 3PM CST ship same business day
Standard delivery: 2-5 business days
Express shipping available at checkout
Free shipping on orders over $75
Tracking number emailed upon shipment

Return Policy

30-day returns on unused parts in original packaging
Electrical parts (capacitors, contactors, control boards) are final sale once installed
Email info@nationalhvacparts.com to initiate a return
Refunds processed within 5-7 business days

OEM Goodman Blower Door Safety S...

$40.95

Frequently Asked Questions

Does this Door Switch fit my Goodman GMTH045-3B — B1370820?

Yes. This is the factory-specified OEM door switch for the Goodman GMTH045-3B — B1370820. It is a direct drop-in replacement that fits without modification. Always verify the model number on your equipment nameplate before ordering.

How do I replace the door switch on my Goodman GMTH045-3B — B1370820?

Refer to your equipment service manual for model-specific steps. General approach: turn off power, photograph connections, remove old part, install new part, restore power and test. For gas components, hire a licensed technician. Email info@nationalhvacparts.com for guidance.

What symptoms mean I need a new door switch?

Common symptoms: unusual noises, intermittent operation, complete failure, or visible damage. Visit our diagnostic hub for symptom-based troubleshooting.

Is this door switch compatible with Bryant or Payne too?

Many Goodman parts are cross-compatible with Bryant and Payne since all three brands are manufactured by Carrier Global Corporation. The same physical part is often used across brand labels with different model numbers. To verify: check your Bryant or Payne equipment service manual for cross-compatible part numbers, or email info@nationalhvacparts.com with your model number.

Should I use OEM or aftermarket for my Goodman door switch?

OEM recommended for reliability and warranty compatibility. OEM parts match exact factory specifications for proper fit, performance, and safety. While aftermarket alternatives cost less upfront, the risk of improper fit and reduced lifespan usually makes OEM the better value long-term.

How fast does National HVAC Parts ship?

Orders placed before 3:00 PM CST ship the same business day. Standard delivery is 2–5 business days anywhere in the continental United States. Express shipping available at checkout. We ship from Houston, TX to all 50 states. 30-day return policy on all parts.

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