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Toto Construction in Ontario, CA | San Mateo Construction
We provide independent Toto service across Ontario, from full bathroom remodels to Washlet repair and one-piece toilet installations. What makes our Toto work here different is that we understand Ontario’s split market: builder-grade Toto fixtures going into multifamily infill near 91761, and older Toto units fighting hard-water scale in the postwar slab homes of 91762 and 91764. We’re not manufacturer-affiliated or authorized. We’re a licensed general contractor who buys Toto parts through the same OEM channels any licensed pro does and fixes what’s actually wrong. Call (855) 901-7266 for a free estimate.
Why Ontario Residents Choose Us for Toto Service
Toto makes a genuinely well-engineered toilet and bidet seat. We’ve installed enough Drakes, Ultramax IIs, EcoPromenades, and Washlets across Ontario to know exactly how they behave after years of Inland Empire water and heat. Noel Carrington, our owner, came up through construction technology at Skyline College and spent decades on California job sites before building San Mateo Construction around one idea: “Tell me what you actually need, and we’ll figure out the right way to build it.” That’s how we approach Toto service in Montclair and across Ontario too. If your bowl and glaze are sound, we repair with genuine Toto OEM parts. If a discontinued Washlet board or cracked one-piece body makes repair the more expensive path, we’ll say so plainly and walk you through replacement options. No authorization agreement with Toto tells us what to do. Your fixture does.
Styles & brands we work with







Common Toto Construction Problems We Solve in Ontario
These are the Toto failures we see most in Ontario homes and commercial spaces:
- Phantom refills on Drake and EcoPromenade toilets. Ontario’s water is hard, and that mineral load accelerates scale on the fill valve and flapper. You hear the tank refill when nobody flushed, or the flush gets weak as the flapper loses its seat. We rebuild these internals with genuine Toto OEM parts, not generic flappers that sort-of fit.
- Washlet electronics dead in the heat. High-desert heat and dust in a garage-adjacent or poorly ventilated Ontario bathroom shorten the life of Washlet control boards, pumps, and seat heaters. It shows up as a dead panel, no warm water, or a seat that won’t heat. We replace with OEM Toto boards and pumps where the part is still in production, and vetted aftermarket only when Toto has discontinued the internal.
- Wax-ring leaks at the flange on older slab homes. The 1940s through 1970s tract homes in 91762 and 91764 sit on slab foundations. Flange height on those original slabs wasn’t set for a modern one-piece toilet, and a Toto Ultramax II or Aquia sits low or rocks. We reset the flange and set the toilet on a proper wax seal so it stops leaking at the base.
- Mineral staining where the tank meets the bowl. Two-piece Toto units go through thermal cycling in this dry climate. When tank-to-bowl bolts or gaskets weep, Ontario’s hard water leaves mineral staining at the base before you ever see standing water. If you’re scrubbing white crust off the back of the bowl, the gasket is already failing.
- Builder-grade fixtures in multifamily infill. Near 91761 and the newer multifamily stock, spec’d Toto EcoPromenade and Drake toilets go in by the dozen. Landlords and property managers call us for multi-fixture punch-list work and warranty-style callbacks when several units show the same fill valve or flapper issue.
Toto Service in Ontario: What Local Conditions Mean for Your Equipment
Ontario’s warehouse and TI construction market pulls a lot of our Toto work into commercial restrooms and builder-grade multifamily infill near 91761, where spec’d Toto EcoPromenade and Drake toilets go in by the dozen. So our Toto service in Ontario—and Toto in Upland nearby—runs as much to multi-fixture punch-list and warranty-style callbacks as it does to single-family bathroom remodels. That’s not a pattern you’ll find in most cities, and it changes how we stock parts and schedule work. A property manager with twelve EcoPromenades showing worn flappers doesn’t need twelve separate diagnoses. They need one crew that shows up with OEM Toto fill valves and flappers in the truck, fixes all twelve in a day, and bills one invoice. That’s exactly what we do. Then there’s the other side of Ontario: the postwar tracts off 91762 in central Ontario, where hard water has been cycling through the same pipes for sixty years and a Toto Drake’s internals give out from mineral scale before the porcelain ever does. A homeowner off 91762 had a Toto Ultramax II that kept phantom-refilling and flushing weak. Our tech found a scaled fill valve and a worn flapper from the hard local water, and the flange sat low on the original slab. We rebuilt the internals with OEM Toto parts, reset the flange with a proper wax seal, and the toilet has flushed clean since. No replacement needed on a sound one-piece body. That’s the Ontario Toto pattern: commercial volume on one side, hard-water wear on the other. We service both.
Toto Models & Products We Service in Ontario
We work on the full Toto lineup you’re most likely to find in Ontario: the Drake two-piece gravity toilets (CST744 and CST454), Ultramax II one-piece high-efficiency toilets, EcoPromenade and Aquia high-efficiency models, and the Washlet bidet seat family including the S350e, S500e, and C100. Parts matter more than most people realize. We use genuine Toto OEM fill valves, flappers, and Washlet boards and pumps where the part is still in production. When Toto discontinues an internal, we only use vetted aftermarket replacements. No mystery-brand electronics going into a Washlet on our watch. For Ontario turnaround—and Toto repair in Chino when called—we keep common OEM Toto internals stocked locally so a Drake rebuild or Washlet board swap doesn’t wait on a freight shipment from a distributor.
See the difference
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AfterToto Service Pricing in Ontario
What you’ll pay for Toto work in Ontario depends on what the fixture needs. A fill valve and flapper rebuild on a Drake runs a fraction of a full bathroom remodel. A discontinued Washlet board can push a repair toward replacement territory, and we’ll tell you that honestly before any work begins. Here’s what our Toto-related construction services run in this market:
| Service | Price Range |
|---|---|
| Full Bathroom Remodeling | $9,000 – $28,000 |
| Walk-In Shower Installation | $4,500 – $12,000 |
| Bathroom Vanity Installation | $800 – $3,000 |
| Tub-to-Shower Conversion | $3,500 – $10,000 |
Every estimate is free and comes as a written line-item quote. You’ll see exactly what parts we’re using and what labor costs. Call (855) 901-7266 and we’ll get you numbers, not vague ranges.
Serving Ontario, CA — Our Local Coverage Area
We’re based in the Ontario area and know this community well, including Toto in San Antonio Heights. Use the map below to see our service coverage — if you’re nearby, we can almost certainly help.
FAQs – Toto Construction in Ontario
We service both Toto toilets and Washlet bidet seats throughout Ontario, including the S350e, S500e, and C100 lines. Most Washlet failures we see here are heat and dust related: dead control boards, pumps that stop producing warm water, and seat heaters that quit. We diagnose the board or pump first and replace with genuine OEM Toto parts when the part is still in production. Call (855) 901-7266 for a free estimate on your Washlet.
That phantom refill is almost always a scaled fill valve or a worn flapper. Ontario’s hard Inland Empire water deposits mineral scale on the fill valve seat and the flapper loses its seal, so the tank slowly drops and the valve kicks on to top it off. In our experience across 91762 and 91764, a genuine OEM Toto fill valve and flapper rebuild fixes it in about an hour. Call (855) 901-7266 to schedule a service visit.
Yes, and we do it regularly. The postwar slab homes in central Ontario were built when standard toilets sat differently on the flange. A modern Toto Ultramax II or Aquia one-piece often sits low or rocks on those original slabs. We reset the flange, set a proper wax seal, and mount the toilet so it sits solid and doesn’t leak at the base. Call (855) 901-7266 and we’ll come look at your flange.
Yes. Our full bathroom remodels in Ontario include Toto toilet and Washlet installation as part of the scope, along with walk-in showers, vanities, and tub-to-shower conversions. Since we’re a general contractor, not just a fixture installer, the same crew that sets your Toto also handles tile, waterproofing, plumbing, and the permit package. Call (855) 901-7266 to discuss your remodel and get a written quote.
No. We’re an independent contractor, not a Toto-authorized service provider or manufacturer affiliate. We buy Toto parts through the same OEM distribution channels any licensed contractor can, and we repair or replace based on what the fixture actually needs. Being independent means we’re not locked into a manufacturer’s service schedule or pricing, and we’ll recommend the repair or replacement that makes sense for your budget. Call (855) 901-7266 and we’ll give you honest guidance, not a sales pitch.
Service Areas Near Ontario
We serve Ontario and the surrounding Inland Empire. If you’re in Apple Valley, our Toto service covers hard-water scale and Washlet repairs there too. We also handle Toto service in Rancho Cucamonga and the broader Ontario service area, including all four Ontario ZIP codes. For Toto parts, fixtures, or full remodels anywhere in the region, our Toto sales & service page covers the model lines and repair approach in more detail.
Book Your Toto Service in Ontario Today
Whether it’s a phantom-refilling Drake off 91762, a dead Washlet in a builder-grade unit near 91761, or a full bathroom remodel with Toto fixtures throughout, we’re ready to get it done right. Call (855) 901-7266 and tell us what you actually need. We’ll figure out the right way to build it.
Written by Noel Carrington, Owner at San Mateo Construction, serving Ontario and the Inland Empire.