Do I Need a Permit to Replace a Water Heater in Colorado?
Quick Answer
Yes — even for a like-for-like replacement.
Why a Simple Swap Needs a Permit
Most jurisdictions require a permit for all water heater replacements, even when you're installing the same type and size. The permit ensures proper venting, gas connections, temperature/pressure relief valve discharge, and seismic strapping. Improper water heater installations are a leading cause of residential CO poisoning and water damage.
What Inspectors Check
The inspector will verify: gas line connections and drip leg (sediment trap), proper venting (metal B-vent for standard, PVC for high-efficiency), T&P relief valve discharging to within 6 inches of the floor or exterior, seismic strapping (two straps — upper and lower third), and adequate combustion air supply.
Tankless Conversion
Converting from a tank to tankless water heater often requires additional work: a larger gas line (tankless units draw more BTUs), PVC venting (most tankless units are high-efficiency), and potentially an electrical outlet for the unit. This may trigger both plumbing and gas permits.
DIY vs. Hiring a Plumber
Many jurisdictions allow homeowners to replace their own water heater in their primary residence — confirm with your city. You still must pull the permit and pass inspection. Most homeowners hire a licensed plumber because the permit and inspection process is simpler when the contractor handles it.
Bottom Line
Yes, you need a $40-$60 permit. It's a quick same-day approval and one final inspection. Don't skip it — it protects you and your home.
Permit fees by city in Colorado
Verified from each city’s published fee schedule. Where a city has no separate fee listed for this project, open the city page for the current requirements and amount.
| City | Permit fee | Source |
|---|---|---|
| Arvada | Assessed as the Table 18-1 valuation-based Building Permit Fee (same schedule as new construction; see Residential Building Permit fee tiers, $34 minimum up to $5,669.25 + $3.45/$1,000 over $1M) plus Use TaxVerified | Plumbing Permit → |
| Aurora | $99.00Verified | Plumbing Permit → |
| Boulder | $68.85Verified | Plumbing Permit → |
| Colorado Springs | $40.00Verified | Plumbing Permit → |
| Denver | Assessed on the plumbing work's valuation using Denver's Building Permit and Plan Review Fee Schedule (ADMIN 125/138 Table 1) — e.g. $35 for $501–$2,000 valuation, $35 for the first $2,000 plus $8/each additional $1,000 up to $25,000, scaling up through the table's brackets to $5,385 for the first $1,000,000 plus $3.65/each additional $1,000 over that; quick permits carry $0 plan review fee (Table 2 valuation applies if higher than the applicant-submitted valuation)Verified | Plumbing Permit → |
| Fort Collins | $65.00Verified | Plumbing Permit → |
| Lakewood | $80.00Verified | Plumbing Permit → |
| Longmont | $40.00Verified | Plumbing Permit → |
| Thornton | $30.00Verified | Plumbing Permit → |
| Westminster | An additional 15% of the Building Permit Fee, plus 15% of the Plan Review FeeVerified | Plumbing Permit → |