Washington's refrigerant rule and what it means for replacements

Since January 1, 2026, the Washington Department of Ecology has required newly installed residential air conditioners and heat pumps to use a refrigerant with a global warming potential, or GWP, below 750. R-410A, the refrigerant in most systems installed over the past decade and a half, does not meet that limit. Any heat pump replaced in Washington now gets equipment built for a newer refrigerant.

The Seattle Heat Pump Company plans and manages heat pump replacements in Seattle and King County, carried out by licensed and insured contractors, and this rule now shapes nearly every replacement quote. Here is what changed and how it affects your project.

What the rule says

Washington’s hydrofluorocarbon rules set GWP limits by equipment type. For new residential air conditioning and heat pump systems, the limit since January 1, 2026 is a GWP under 750. GWP compares how much heat a gas traps in the atmosphere relative to carbon dioxide. R-410A sits around 2,088, far above the limit. The refrigerants replacing it, mainly R-454B at roughly 466 and R-32 at roughly 675, fall under it.

Federal timelines for R-410A have shifted, but Washington kept its own rule in place. For a house in Seattle, Bellevue or anywhere else in the state, the Washington limit is the one that decides what can be installed.

What it does not do

The rule covers newly installed equipment. It does not require you to remove a working R-410A heat pump, and it does not stop a technician from servicing one. If your system is a few years old and running well, nothing about this rule forces a change.

Where it bites is at the point of replacement. A failing compressor or a leaking coil on an older R-410A system used to raise a repair-or-replace question with a familiar answer on the replace side: swap the outdoor unit and keep the rest. That answer has changed.

Why a replacement is now a bigger job

A split heat pump is a matched set. The outdoor unit, the indoor coil or air handler, the metering device and the refrigerant all have to work together, and the equipment is rated and warrantied as a system. A new outdoor unit designed for R-454B or R-32 cannot simply be connected to an indoor coil built for R-410A.

In practice, a replacement now usually includes:

• A new outdoor unit using an A2L refrigerant.
• A new matched indoor coil, or a new air handler if the old one is near the end of its life or the system is going all-electric.
• An evaluation of the existing refrigerant line set, which can be reused only if its sizes suit the new equipment, it passes a pressure test and the manufacturer allows it.
• A commissioning check of airflow, charge and controls, as with any new system.

That broader scope is why replacement prices now cluster higher than an outdoor-unit swap once did. A like-for-like ducted heat pump replacement typically runs about $6,700 to $15,000 in the Seattle area, and an air handler replacement about $1,500 to $4,200 in national figures. These are budgeting ranges, not quotes. The replacement cost guide breaks down what moves the number, and the air handler replacement page covers when the indoor unit goes too.

A2L refrigerants, briefly

R-454B and R-32 are classified A2L. The “A” means low toxicity; the “2L” means lower flammability. They are much harder to ignite than a flammable gas like propane and burn slowly if they do, but they are not completely non-flammable the way R-410A is classified.

That classification drives some practical changes. Equipment and installation standards for A2L systems add requirements such as refrigerant leak detection in many indoor units, which can switch on the blower to disperse refrigerant if a leak is sensed. Technicians use tools and procedures rated for A2L refrigerants. For a homeowner, the visible differences are small: an indoor unit with a sensor, a different refrigerant label, and a contractor who should be able to explain how the system was designed for it. The refrigerant change guide goes deeper on R-454B, R-32 and line set reuse.

What to do if your system is aging

If your R-410A heat pump works, keep it maintained and plan rather than react. A replacement planned in spring or early fall leaves room to get a load calculation, test the ducts and compare equipment, instead of taking whatever is in stock during a cold snap.

When you compare bids, check that each one names the refrigerant, includes a matched indoor coil or air handler, and states whether the line set will be reused or replaced and why. The quote comparison guide has a fuller checklist. In Seattle, a replacement still needs a refrigeration permit obtained by a licensed refrigeration contractor, plus electrical and, where indoor equipment changes, mechanical permits; the Seattle permit guide lists them. The heat pump replacement service page covers how a replacement project runs from assessment to commissioning.