Niagara toilet installation follows standard residential procedures with brand-specific notes for the vacuum-assist mechanism on Stealth Sabre and Stealth-series models. Below: complete installation procedure with Niagara-specific considerations.
Pre-installation requirements
- Verify rough-in distance (typically 12 inches center-of-bolts to finished wall — measure twice)
- Cold-water supply with shutoff valve and braided supply line
- Drain pan installation if above finished space
- Verify drain flange is at floor level (not below; not significantly above)
- New wax ring and closet bolts (don't reuse from old installation)
Tools you'll need
- Pipe wrench (12-inch typically)
- Channel-lock pliers
- Adjustable wrench
- Putty knife for old wax removal
- Bucket and sponge
- Two-person lift (Niagara Stealth Sabre weighs 95-110 lbs empty)
Step 1: Remove old toilet
- Shut off cold water supply
- Flush to drain tank; sponge remaining water
- Open hot faucet upstairs to break vacuum (helpful for drainage)
- Disconnect supply line
- Remove closet bolt nuts
- Lift old toilet straight up
- Scrape old wax from closet flange
Step 2: Position new Niagara unit
Place new wax ring on the closet flange — flange-side placement (vs bowl-side) is more forgiving for first-time installs. Drop in new closet bolts with plastic retainer washers.
Step 3: Set the toilet
Lift the new Niagara unit straight down onto the flange, aligning bolts through base holes. Press straight down with full body weight — compresses the wax ring. Do not rock or twist; both break the wax seal. Hand-tighten the nuts alternately, then wrench another 1/4 turn each side. Stop when toilet is firm against floor.
Step 4: Vacuum-assist commissioning (Stealth-series only)
For Niagara Stealth Sabre and similar vacuum-assist models, the vacuum chamber must commission properly during first fill. Procedure:
- Reconnect cold water supply
- Open the supply valve slowly
- Allow tank to fill to setpoint
- Press the flush handle and immediately re-fill
- Repeat 3-5 times to fully prime the vacuum chamber
- Verify vacuum-assist activates on each flush (audible "whoosh" indicates proper vacuum draw)
Step 5: Leak test
Visual inspection at: bowl-floor joint, supply line connection, tank-bowl gasket (if two-piece). Flush 3 times while observing all joints. No moisture means good seal.
Niagara-specific install notes
- Vacuum-assist Stealth models need full water pressure (50+ psi) for proper commissioning
- Some Niagara models have proprietary supply line connectors — verify compatibility
- Flush valve and fill valve service parts are standard residential
- Warranty registration within 60 days at niagaracorp.com/warranty
Common install mistakes
- Reusing old wax ring (always use new — old wax compresses unevenly)
- Over-tightening closet bolts (cracks porcelain — stop when toilet is firm)
- Rocking the toilet to "seat" the wax (breaks the seal — press straight down)
- Skipping leak test on tank-bowl gasket on two-piece models
- Not commissioning the vacuum chamber on Stealth models (causes weak flushing initially)