American Standard Champion 4 Pressure-Assisted Two-Piece Elongated 1.6 GPF Toilet

The American Standard Champion 4 Pressure-Assisted positioning

The Champion 4 Pressure-Assisted (3279.516) is American Standard's strongest-flush residential toilet — combining the Champion 4's 4-inch flush valve and PowerWash rim with Flushmate Series 503 pressure-assist internals. At $520-$720, the Champion 4 Pressure-Assisted occupies a specific niche: maximum flush velocity available in US residential, full stop. MaP 1,200g+ — meaningfully higher than the Champion 4 gravity (1,000g+) or any standalone pressure-assist (1,000g+).

The Champion 4 Pressure-Assisted is the toilet US plumbers spec when: (a) the household has chronic severe clog problems, (b) the installation is light-commercial residential (B&B, group home, vacation rental with heavy turnover), or (c) the existing drain line has partial obstructions that demand maximum flush momentum to clear. It's overspec for typical residential use but the right answer when flush performance is the absolute priority.

Why combine Champion 4 + Pressure-Assist?

The Champion 4 gravity flush is already strong (MaP 1,000g+) because of its 4-inch flush valve. The Flushmate Series 503 pressure-assist adds compressed air pressure to the flush water before it hits the bowl — accelerating the already-high-velocity flow even further. Combined performance:

• 4-inch flush valve releases the entire 1.6 gallons in ~5 seconds (vs ~7 seconds on standard Champion 4)
• Flushmate pressure vessel adds 25-40 PSI to the water before release
• PowerWash rim cleaning at higher pressure than standard Champion 4
• MaP 1,200g+ — the highest residential MaP score available in the US
• Bowl-cleansing — the combination of high-velocity water + PowerWash rim scrubbing keeps the bowl noticeably cleaner than any other US residential toilet

The Champion 4 Pressure-Assisted variant matrix

What's in the box

• Tank with pre-installed Flushmate Series 503 pressure vessel + Champion 4 trim hardware
• Bowl with Champion 4 engineering — pre-drilled for 12" rough-in
• Chrome trip lever (specifically engineered for Flushmate + Champion 4 actuation)
• Tank-to-bowl gasket and brass bolts
• Wax ring NOT included
• SoftClose seat NOT included — Bemis 1500EC ($35) or AmStd Champion 4 seat ($55-$80) recommended
• Installation manual + Flushmate Series 503 operation manual

Install requirements and procedure

• Rough-in: 12 inches (standard).
• Water supply pressure: 20+ PSI dynamic minimum — Flushmate pressure-assist requires this for proper vessel pressurization.
• Weight: ~100 lbs total (tank ~42, bowl ~58). Two-person install recommended due to weight + Flushmate vessel handling.
• Standard two-piece install procedure — same as Champion 4 with the addition of Flushmate vessel commissioning.
• Flushmate commissioning — after install, run 3-5 test flushes for the vessel to reach full operating pressure. First flush may be weaker than subsequent.
• Cold-climate consideration — pressure vessel can crack in unheated bathrooms during freeze cycles. Don't install in unheated outbuildings without consistent heating.

What owners report

• The flush is genuinely unmatched. Owners describe it as "noticeably more powerful than any toilet they've owned" — the combination of 4-inch valve + pressure-assist creates flush velocity that's audibly different.
• Clog problems disappear entirely. Households that have struggled with clog issues even after upgrading to standard Champion 4 report complete resolution after switching to the Pressure-Assisted variant.
• The flush noise is loud. Pressure-assist + 4-inch valve + PowerWash rim combined produce a flush that's meaningfully louder than any gravity-flush alternative. Owners in master baths adjacent to bedrooms occasionally find the noise problematic.
• EverClean glaze + powerful flush combination keeps the bowl noticeably cleaner than any other US residential toilet.
• Flushmate Series 503 service life: 10-15 years typical. Vessel replacement when failure occurs: $130-$180 + plumber labor.
• Service life: 25-30 years porcelain.
• The 10-year Champion flush engine warranty applies to the bowl-side engineering; the 5-year Flushmate warranty applies to the pressure vessel separately.

Where Champion 4 Pressure-Assisted wins

Where Champion 4 Pressure-Assisted loses

• Flush noise — meaningfully louder than gravity-flush alternatives
• NOT WaterSense (1.6 GPF base SKU) — not rebate-eligible (1.28 GPF variant 3279.014 is rebate-eligible)
• Flushmate vessel replacement cost at 10-15 years ($130-$180 + labor) vs $5 flapper on gravity Champion 4
• Cold-climate freeze risk on pressure vessel
• Higher initial cost than standard Champion 4 ($190-$260 premium)

The verdict

Buy Champion 4 Pressure-Assisted if:

• Household has chronic SEVERE clog problems that standard Champion 4 doesn't fully resolve
• Light-commercial residential (B&B, group home, heavy-turnover vacation rental)
• Older home with documented drain-line partial obstructions where maximum flush momentum is needed
• Multi-resident bathroom with extreme heavy-paper-use patterns
• You're not noise-sensitive and can accept Flushmate replacement at 10-15 years

Skip and choose Champion 4 gravity if:

• Standard household use where Champion 4's gravity MaP 1,000g+ is sufficient
• Noise sensitivity matters
• Budget under $500
• You prefer simpler service ($5 flapper replacement vs Flushmate vessel)

Warranty

American Standard Champion 4 Pressure-Assisted residential warranty: 1 year on tank trim, lifetime on porcelain, 10-year flush engine warranty (bowl-side), 5-year Flushmate Series 503 vessel warranty (Flushmate-administered separately from AmStd customer service).

Pricing reality (2026)

Champion 4 Pressure-Assisted 3279.516 (White, 1.6 GPF): $520-$620. Home Depot: $549-$639. Lowes: $529-$619. Build.com: $499-$579. Ferguson trade: $479-$549. Linen/Bone variants +$40-$60. WaterSense 1.28 GPF variant (3279.014) +$40-$80 — worth the premium for rebate eligibility in CA/AZ/TX programs.