R404A Replacement Guide UK: Step-by-Step Retrofit to R448A or R449A

Why You Should Plan Your R404A Replacement Now

With UK F-Gas quotas tightening and R404A prices rising significantly, now is the time for refrigeration engineers and facility managers to plan the transition to lower-GWP alternatives. R448A and R449A offer around 65% lower GWP than R404A and are compatible with most existing R404A commercial refrigeration equipment.

Step 1: Assess the System

• Record current refrigerant type and charge weight
• Check compressor manufacturer approval for R448A or R449A compatibility
• Verify expansion valve type — TEV or EEV — and check if adjustment will be needed
• Confirm oil type is POE (both R448A and R449A require POE oil, same as R404A)

Step 2: Recover Existing R404A

Use an F-Gas-compliant recovery machine to fully recover the R404A charge into a dedicated recovery cylinder. Record the weight recovered in the system logbook. Send full recovery cylinders to an approved reclaim facility.

Step 3: System Check and Oil Top-Up

After recovery, check the system for leaks under dry nitrogen. If the oil is heavily contaminated or discoloured, consider an oil change. Both R448A and R449A are compatible with POE oils already used with R404A, but fresh oil improves system cleanliness.

Step 4: Recharge With R448A or R449A

Pull a vacuum to 500 microns and hold for 30 minutes. Recharge the system with the new refrigerant by weight. The new charge weight will typically be 95–98% of the original R404A charge weight — consult manufacturer guidance for the specific replacement.

Step 5: Adjust TEV and Verify Performance

TEV superheat may need adjustment after the switch. Check superheat, subcooling and system temperatures against specification. Log the new refrigerant type, charge weight and date in the system record.

For R404A service stock while transitioning existing systems, our R404A 10.9 kg cylinders remain available. Browse our full refrigerant range.