Photo may vary slightly — verify by part number before ordering.York S1-02543257000 Modulating Gas Valve, Gen 2, Natural Gas, White-Rodgers 36J27-508 | OEM Source 1 Part
In stock and ordered before 1pm ET, Mon–Fri? It ships the same day from our US warehouse.
Not sure it's the right part? Send the model and serial — help@totalhvacparts.com or 302-219-4994.
Need more than 101? Ask about factory lead time — we'll give you a real date, not a guess.
Min. order: 1 unit · Weight: 2.03 lb
Overview
The York S1-02543257000 (025-43257-000) is a Gen 2 modulating gas valve. A modulating valve adjusts gas flow to the burners to match heating demand, so a modulating furnace can run at different firing rates. It is the genuine York Source 1 (S1) part for York, Coleman and Luxaire equipment. Confirm fit by your unit's model and serial number and the number on the old valve.
Key details
- Modulating gas valve, Gen 2 (York description: gas valve, modulating, GEN2)
- Natural gas
- Also described as a 97% modulating gas valve
- Sold as a single valve
Also known as / replaces
Also searched as 025-43257-000 and S1-025-43257-000. Supplier listings identify this as White-Rodgers 36J27-508.
Common questions
What does a modulating gas valve do?
It varies the gas flow to the burners to match heating demand instead of only switching between fully on and off, which lets a modulating furnace change its firing rate.
Is this a natural gas or LP valve?
It is listed as a natural gas valve. If your furnace runs on propane (LP), send us the model and serial number before you order.
How do I confirm this valve fits my furnace?
Match the York number on the old valve and check that it is a Gen 2 modulating valve. Then send us your unit's model and serial number and we will help confirm.
What should I do before replacing a gas valve?
Shut off the gas supply and the power before removing the old valve. After installation, leak-test every gas connection with an approved method and follow the furnace manufacturer's instructions.
Why buy from Total HVAC Parts: Genuine York Source 1 OEM parts, supplied through authorized York OEM channels. Full manufacturer warranty applies. Need help confirming fit? Send us your unit's model and serial number before you order.
Shipping: Ships same or next business day. Free shipping on orders over $50; flat-rate shipping under $50. Returns follow our standard parts return policy.
Specifications
Values in italic are not yet confirmed from OEM documentation. Ask us to verify before ordering.
After You Order
Order number and confirmation by email the moment you check out.
In stock — ships the same or next business day, Monday–Friday, from our shelf or York's parts warehouse. Tracking follows by email the moment it leaves.
Tracking number lands in your inbox the moment it leaves the building.
Check the part number on the label against your order before installing. Wrong or damaged? Tell us — we'll sort it out.
Ask the Parts Desk
Not sure this fits? Need more than what's in stock? Send the model and serial from the unit's data plate — a real person reads it and confirms before you order.
Common Questions
Is the stock number on this page real?
Yes. The number on this page is the stock available to ship now for S1-02543257000: our own shelf plus York's parts warehouses, checked daily (last checked Oct 27, 2026). Above 100 it shows as 100+.
Is this a genuine York part, or aftermarket?
Genuine York OEM equipment sourced through York's authorized parts program — not an aftermarket substitute.
How do I confirm this fits my unit?
Match part number S1-02543257000 to your unit's parts diagram. If unsure, send us your model and serial number and we'll verify before you order.
I see this listed under a different name on other sites. Is it the same part?
Yes — manufacturers and distributors sometimes use different brand names or legacy labels for the same part number. Part number S1-02543257000 is identical across all name variations.
What's the warranty on this part?
Warranty terms vary by manufacturer. Contact us with your order number for details specific to this part.
How fast does this ship?
In-stock items ship the same business day on orders placed before 1pm ET, Monday–Friday. Standard ground delivers to most of the continental US in 2–5 business days. Ships via UPS/FedEx Ground, or truck freight for oversized items. Free standard shipping (US).
Does everything ship UPS or FedEx Ground?
Most orders ship UPS or FedEx Ground. A small number of large or heavy parts across the catalog ship by truck freight instead, and we reach out to arrange a delivery window before those orders leave the warehouse. Oversized items that ship by truck freight are also covered by free standard shipping on orders of $50 or more.
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Not sure it's the right part? send us the model and serial — help@totalhvacparts.com or 302-219-4994.