Answering the search intent: when you need a combustion air or draft-proving pressure switch, choose a replacement that matches your furnace model and operating range for safe, reliable ignition. The top picks below cover 90%+ efficiency furnaces and common brands, making them suitable for DIY replacements or professional installs. Best-for profiles: homeowners maintaining older units, contractors updating multiple furnaces, and RV/water heater setups requiring robust safety switches.
The table below compares five well-matched options to help you decide quickly. It highlights the product, what it’s best for, and a key note on suitability or limitation.
| Product | Brand | Best For | Notes |
|---|---|---|---|
| 632444 Furnace Air Pressure Switch | Yoursme | Nordyne/Intertherm/Miller/Gibson and similar gas furnaces | Widely used 632444 variant; direct replacement for several part numbers |
| OEM Upgraded Goodman Furnace Vent Air Pressure Switch B13701-42 | Goodman | Goodman furnace systems requiring OEM parts | Two terminals and one hose port; upgraded OEM part |
| Water Heater Air Pressure Switch (Camplux/Ranein/Girard, etc.) | ULZOZN | RV water heaters and gas tankless heaters | Broad compatibility; safeguards ignition with safe cutoff |
| Breckwell & US Stove Air Switch 80621 | Pellethead | BRECKWELL and US STOVE pellet stove models | Replaces PART NUMBERS C-E-201 & 80621 |
| NORDYNE 632444R Pressure Switch | Nordyne | Nordyne/Intertherm/Miller style furnaces | Combustion air switch; 1.74″ WC; draft proving |
632444 Furnace Air Pressure Switch / Combustion Air Switch
The 632444 model is a widely used replacement for gas furnaces across multiple brands. Best for Nordyne, Intertherm, Miller, Gibson, Frigidaire, Westinghouse, Philco, Tappan, and other brands that rely on a 1.74-inch WC pressure switch. It is a direct replacement for several part numbers (632444, 632444R, 632252, MPL-9300-1, and more). It includes installation instructions for a smoother replacement. This switch closes when the furnace’s draft inducer runs, creating negative air pressure to prevent gas leakage. Caution: ensure model compatibility before purchase to avoid mismatches with your system’s venting setup.
OEM Upgraded Goodman Vent Air Pressure Switch B13701-42
This Goodman OEM pressure switch is designed for Goodman furnaces that require an OEM replacement. It features two wiring terminals and one hose port, making it straightforward to install in compatible Goodman models. Best for homeowners maintaining Goodman systems that call for an authentic OEM part. Choose this if your unit specifies B13701-42; avoid if your furnace uses a different OEM part number or non-OEM equivalent that could affect safety certifications.
Water Heater Air Pressure Switch for Camplux/Ranein/Girard
Designed for water heaters in RVs and similar applications, this ULZOZN switch provides broad compatibility with Camplux, Ranein, RecPro, Girard, and related models. It monitors combustion chamber pressure to ensure safe ignition and stable burner performance. Best for RV owners and off-grid setups where a robust, reliable switch is needed. Limitation: check your heater’s venting and gas valve configuration to confirm a fit.
Breckwell & US Stove Air Switch 80621
Pellet stove owners can rely on this air switch to fit Breckwell and US Stove models, including P20, P2000, P22, P24, P26, P2700, and more. It replaces PART NUMBERS C-E-201 and 80621, providing a practical, widely compatible solution for pellet burning appliances. Best for pellet stove users who need a straightforward, compatible switch. Limitation: verify exact model compatibility with your stove before ordering to avoid fit issues.
Nordyne 632444R Combustion Air Switch
This 632444R is a Nordyne variant that serves as a combustion air switch and a draft-proving device. It closes when the combustion/booster motor operates, creating negative air pressure. Best for Nordyne, Intertherm, and similar furnace families that require a 1.74-inch switch with draft-proving functionality. Choose this if your unit specifies 632444R or a Nordyne-compatible replacement. Limitation: ensure your model’s exact switch standard aligns with a 1.74″ WC specification.
NS2000001 ClimaTek Upgraded Universal Gas Furnace Air Pressure Switch Kit
ClimaTek’s NS2000001 is a universal gas furnace air pressure switch kit marketed as an upgraded replacement. It’s designed to directly replace NS2000001 and is positioned as a durable, long-lasting part. Best for installers seeking a universal option that can cover multiple furnace brands. Limitation: verify that your furnace model is compatible with a universal kit rather than a brand-specific switch.
Tridelta PPS10009-2174 1.38″ WC Furnace Vent Air Switch
Tridelta’s PPS10009-2174 is a 1.38″ WC vent air switch designed for furnace venting and draft proving. Best for systems that specify a 1.38″ WC threshold. Pros include straightforward replacement and reliable operation. Limitation: check the exact venting and wiring configuration on your furnace to ensure a proper match.
Furnace Air Pressure Switch Replaces Goodman B13701-42
This ClimaTek part offers a top-quality replacement for Goodman B13701-42 and B1370142. It’s positioned for U.S.-made manufacturing quality and is suitable when the unit requires a ClimaTek replacement with similar specifications. Best for Goodman installations seeking a domestic-made replacement. Limitation: ensure compatibility with the exact Goodman model number in your system’s documentation.
Buying Guide
What to check before you buy a combustion air pressure switch
- Vent and measurement: Confirm the correct inches of water (WC) rating your furnace requires (commonly 1.38″–1.74″ WC) and that the switch is compatible with draft-proving or combustion air roles.
- Brand compatibility: If your furnace is from Nordyne, Goodman, Tridelta, or similar, prefer brand-specific or OEM replacements to keep safety certifications intact.
- Wiring and hoses: Verify the number of wiring terminals and hose ports to fit your furnace wiring harness and vent hoses.
- Installation ease: Look for parts with clear installation instructions or kits that include necessary gaskets and fittings.
- Safety and testing: Choose switches designed to shut off gas if abnormal pressure occurs, reducing the risk of gas leakage during ignition.
How to compare options quickly
- Direct replacement vs universal kit: Direct replacements reduce the risk of mismatches; universal kits offer flexibility across models.
- OEM vs aftermarket: OEM parts align with original specifications; quality aftermarket parts can be cost-effective but verify compatibility.
- Application: Reserve water heater and RV-rated switches for those specific systems; residential furnaces typically need furnace-rated switches.
FAQ
- What is a combustion air pressure switch used for? It ensures the furnace drafts correctly and shuts off gas if improper pressure is detected.
- Can I replace a pressure switch myself? Yes, with careful adherence to the furnace’s wiring diagram and safety procedures, though a professional is recommended for complex systems.
- What does 1.74″ WC mean? It is the nominal pressure the switch detects when the draft inducer runs; ensure your system requires this rating.
- Is an OEM switch always better? OEM parts match original specifications, but high-quality aftermarket options can work well when OEM is unavailable.
- How do I know which part number to buy? Check your furnace model and the part number on the existing switch, or consult the furnace’s manual for compatibility.
- Do these switches affect efficiency? They primarily affect safety and ignition reliability, indirectly supporting consistent burner performance.