Do I Need a Permit to Replace a Water Heater in Montana?
Water heater replacement permit requirements. Yes, even for like-for-like swaps. What inspectors check and how to pass.
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.
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 Montana
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.
40 rows
| Permit fee | Source | |
|---|---|---|
| Anaconda-Deer Lodge | $10 eachVerified | Plumbing Permit → |
| Belgrade | $10 eachVerified | Plumbing Permit → |
| Billings | $20.00Verified | Plumbing Permit → |
| Bozeman | Determined based on contractor valuation of the project, subject to Building Division approval of the valuation, applied against Table CVerified | Plumbing Only Permit → |
| Butte-Silver Bow | $75.00 per hour, one-hour minimumVerified | Plumbing Permit → |
| Choteau | See city page for the current Residential Building Permit (New Construction / Addition / Alteration) fee | Residential Building Permit (New Construction / Addition / Alteration) → |
| City of Deer Lodge | $10 eachVerified | Plumbing Permit → |
| Colstrip | See city page for the current Residential Building Permit (New Construction / Addition / Alteration / Repair / Move) fee | Residential Building Permit (New Construction / Addition / Alteration / Repair / Move) → |
| Columbia Falls | $30.00Verified | Plumbing Permit → |
| Conrad | See city page for the current Zoning and Building Permit (New Construction / Addition / Alteration / Repair) fee | Zoning and Building Permit (New Construction / Addition / Alteration / Repair) → |
| Cut Bank | $23.50 (subject to the $100.00 minimum permit fee)Verifiedvia Residential Building Permit (New Construction / Addition / Alteration) | Residential Building Permit (New Construction / Addition / Alteration) → |
| Darby | $75 for the first $1,000 plus 2.0% of the balance of construction valueVerified | Plumbing Permit → |
| East Helena | $60Verified | Plumbing Permit (including Water Heater) — State-Issued → |
| Forsyth | See city page for the current Residential Building Permit (New Construction / Addition / Alteration) fee | Residential Building Permit (New Construction / Addition / Alteration) → |
| Glasgow | See city page for the current Residential Building Permit (New Construction / Addition / Alteration) fee | Residential Building Permit (New Construction / Addition / Alteration) → |
| Great Falls | $34.39Verified | Plumbing Permit → |
| Hamilton | $75 (for services under 1 hour); $35 per additional 30-minute increment beyond 1 hour; travel/per diem may be charged at the State of Montana's existing rateVerified | Plumbing Permit → |
| Hardin | See city page for the current Residential Building Permit (New Construction / Addition / Alteration / Re-Roof) fee | Residential Building Permit (New Construction / Addition / Alteration / Re-Roof) → |
| Havre | $60Verified | Residential Plumbing Permit (including Water Heater) → |
| Helena | $21.00Verified | Plumbing Permit → |
| Kalispell | $20.00 base fee plus $8.00 per plumbing fixture and/or gas outletVerified | Plumbing Permit → |
| Laurel | $25Verified | Residential Plumbing Permit (State-Issued, including Water Heater) → |
| Lewistown | See city page for the current Residential Building Permit (New Construction / Additions) fee | Residential Building Permit (New Construction / Additions) → |
| Libby | $24Verifiedvia Residential Building Permit (New Construction / Addition / Alteration / Repair) | Residential Building Permit (New Construction / Addition / Alteration / Repair) → |
| Livingston | $25Verified | Plumbing Permit (State-Issued, including Water Heater) → |
| Manhattan | See city page for the current Plumbing Permit fee | Plumbing Permit → |
| Miles City | $60Verified | Plumbing Permit (State-Administered) → |
| Missoula | $43.00Verified | Residential Plumbing Permit → |
| Missoula County (Unincorporated) | $44.00Verified | Plumbing Permit (MP) → |
| Polson | $35.00Verified | Plumbing Permit → |
| Red Lodge | See city page for the current Residential Building Permit (New Construction / Addition / Alteration) fee | Residential Building Permit (New Construction / Addition / Alteration) → |
| Ronan | $35.00 for up to $1,999Verifiedvia Building Permit (New Construction / Addition / Alteration / Repair) | Building Permit (New Construction / Addition / Alteration / Repair) → |
| Shelby | $23.50Verifiedvia Building Permit (New Construction / Addition / Structural Alteration) | Building Permit (New Construction / Addition / Structural Alteration) → |
| Sidney | $10 eachVerified | Plumbing Permit → |
| Stevensville | $25.00Verified | Plumbing Permit → |
| Townsend | $60Verified | Plumbing Permit (including Water Heater) — State-Issued → |
| Troy | $24Verifiedvia Residential Building Permit (New Construction / Addition / Alteration / Repair) | Residential Building Permit (New Construction / Addition / Alteration / Repair) → |
| Unincorporated Yellowstone County | $25Verified | Water Heater Permit → |
| West Yellowstone | See city page for the current Residential Building Permit (New Construction / Addition / Alteration / Repair) fee | Residential Building Permit (New Construction / Addition / Alteration / Repair) → |
| Whitefish | Based on a percentage of the estimated project cost/valuation, consistent with the City's general building-permit valuation-based fee methodology; a deposit is required at time of permit submittalVerified | Plumbing Permit (Trade Permit) → |