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How to Hire a Plumbing Contractor in Ontario

Plumbing is a compulsory trade in Ontario — it's illegal to hire an unlicensed plumber. The Ontario College of Trades (now Skilled Trades Ontario) oversees licensing. Always verify your plumber's 306A licence before work begins.

Ontario Plumbing Licensing Requirements

Ontario College of Trades — Licensed Plumber (306A)

Plumbing is a compulsory trade in Ontario — must be licensed.

Verify a Plumbing Contractor's Licence

When to Hire a Plumbing Contractor

  • Your water heater is over 10 years old or leaking
  • You have recurring drain clogs or slow drains
  • You notice water stains on ceilings or walls
  • Your water pressure has dropped significantly
  • You're renovating a kitchen or bathroom
  • You smell sewer gas in your home
  • Your water bill has spiked unexpectedly (possible hidden leak)

Timeline: Simple repairs take 1-4 hours. Water heater replacement is typically same-day. Bathroom rough-in takes 2-3 days. Full bathroom renovation plumbing takes 3-5 days.

Plumbing Costs in Ontario (2026)

Water Heater$1,200 — $3,500
installed
Bathroom Rough In$3,000 — $8,000
complete
Drain Cleaning$150 — $500
per service
Pipe Repair$200 — $2,000
per repair

Prices are approximate for Ontario (CAD). Actual costs vary by city, scope, and season. Always get 3 written quotes.

Questions to Ask Before Hiring

  1. 1What is your Ontario plumbing licence number (306A)?
  2. 2Do you carry WSIB coverage?
  3. 3Will you pull the required plumbing permit?
  4. 4What is your hourly rate vs. flat rate for this job?
  5. 5Do you offer emergency/after-hours service?
  6. 6What is the warranty on your work?
  7. 7Do you provide camera inspection before recommending repairs?

Red Flags — When to Walk Away

  • No license number
  • Won't pull permits
  • No WSIB
  • No written quote

Homeowner Checklist — Before You Hire

  • Get at least 3 written quotes for comparison
  • Verify WSIB clearance certificate (protects YOU from liability)
  • Check Google reviews AND ask for local references
  • Confirm they will pull all required permits
  • Never pay more than 10-15% deposit upfront
  • Get everything in writing — scope, timeline, payment schedule
  • Verify their business insurance is current
  • For regulated trades (electrical, plumbing, gas), verify their license number

Payment: 10-15% deposit, progress payments tied to milestones, 10% holdback until completion. Ontario's Construction Act provides a 10% holdback right on construction projects.

Best Time to Hire a Plumbing Contractor

springMarch — May

Spring is peak booking season. Contact contractors in February for the best availability.

summerJune — August

Summer is the busiest season. Prices are highest and wait times longest. Book early.

fallSeptember — November

Fall is the sweet spot — contractors are less busy, prices drop, and you prepare for winter.

winterDecember — FebruaryRelevant

Winter is off-season for exterior work. Interior renovations get the best prices and fastest timelines.

How to Verify a Plumbing Contractor in Ontario

Frequently Asked Questions — Hiring a Plumbing in Ontario

Do I need a licensed plumbing contractor in Ontario?
Ontario College of Trades — Licensed Plumber (306A)
How much does plumbing work cost in Ontario?
Water Heater: $1,200-$3,500 (installed). Bathroom Rough In: $3,000-$8,000 (complete). Drain Cleaning: $150-$500 (per service). Pipe Repair: $200-$2,000 (per repair). Prices are approximate and vary by region.
How do I verify a plumbing contractor in Ontario?
Check WSIB coverage at wsib.ca. Verify their licence at https://www.skilledtradesontario.ca/. Always get 3 written quotes.
How much deposit should I pay a contractor?
10-15% deposit, progress payments tied to milestones, 10% holdback until completion. Ontario's Construction Act provides a 10% holdback right on construction projects.
What are the red flags when hiring a plumbing contractor?
No license number. Won't pull permits. No WSIB. No written quote.
What if I have a dispute with my contractor?
Ontario Consumer Protection, Better Business Bureau, Small Claims Court (up to $35,000). Document everything and keep copies of all contracts and receipts.

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