Water Heater Replacement & Installation in Overland Park, KS
When a tank starts leaking or a heater is past the point of sensible repair, the goal is simple: hot water back quickly, with a heater that fits your household and is installed to current code. That last part matters more than most people think. Venting, gas connections, expansion tanks, relief-valve discharge and drain pans all get checked when a heater is replaced.
Local Overland Park plumber · Open 7 days, 7 AM–8 PM
Choosing the right replacement
Most replacements are like-for-like: same fuel, similar capacity, same location. That keeps the job simpler. It’s also the right moment to ask whether your household has changed. A family that regularly runs out of hot water may need a larger tank or a higher first-hour rating, not just a newer heater.
Options we’ll walk through: standard atmospheric-vent gas, power-vent gas (useful when a chimney or vent path is a problem), electric, heat-pump (hybrid) electric, and high-efficiency models. If you’re curious about going tankless, compare it on our tankless page before you decide.
Sizing: first-hour rating beats tank size
The yellow EnergyGuide label lists a first-hour rating (FHR): roughly how many gallons of hot water the heater can deliver in an hour starting with a full tank. Gas heaters recover faster than standard electric ones, so a 40-gallon gas tank can out-deliver a 50-gallon electric tank in a busy hour.
To estimate your need, think about your busiest hour: back-to-back showers, a dishwasher and a load of laundry. A typical shower uses roughly 10–20 gallons of hot water depending on length and showerhead. Add up the overlap and choose a heater whose FHR covers it.
- 1–2 people: often fine with a 30–40 gallon gas or 40–50 gallon electric tank
- 3–4 people: commonly 40–50 gallon gas or 50–65 gallon electric/hybrid
- 5+ people, big tubs or body sprays: look at 50+ gallon gas, high-recovery models, or tankless
Tank, hybrid or tankless?
| Standard tank | Heat-pump (hybrid) electric | Tankless (gas) | |
|---|---|---|---|
| Upfront cost | Lowest | Higher | Highest, especially if the gas line or venting changes |
| Operating cost | Baseline | Much lower than standard electric | Lower than a gas tank for most households |
| Space needs | Same as today | Needs room air and a condensate drain; cools the space it’s in | Wall-mounted; needs dedicated venting and often a bigger gas line |
| Hard-water upkeep | Flush sediment | Flush sediment, clean air filter | Regular descaling of the heat exchanger |
| Runs out? | Yes, when the tank is spent | Yes; slower recovery in heat-pump-only mode | No, but flow is limited at once |
Talk to a plumber about water heater replacement & installation
Call (913) 379-3324 or book online. Open 7 days, 7 AM–8 PM.
What a proper installation includes
- Shutting off and draining the old heater, and hauling it away
- Setting the new heater, with a drain pan where one is required
- Gas connection with a sediment trap and leak test, or a correctly sized electric circuit
- Venting checked for correct size, slope and draft
- Thermal expansion tank where the system is closed (for example, with a pressure-reducing valve)
- Relief-valve discharge line run to an approved location
- Permit and inspection where the city requires it
Pressure and expansion: the part that gets skipped
The 2024 International Plumbing Code, which Overland Park adopted, requires a pressure-reducing valve when static water pressure exceeds 80 psi, and it requires a way to control thermal expansion when a backflow preventer, check valve or pressure-reducing valve makes the system closed. In practice that means checking your house pressure with a gauge and installing or replacing a correctly sized expansion tank when the heater goes in. Skip it and the new heater’s relief valve often starts dripping within weeks.
Source: Overland Park Ordinance BC-3499 (2024 International Codes, effective July 1, 2026). Checked October 2026.
Permits in Overland Park, Olathe and Lenexa
Overland Park adopted the 2024 International Plumbing Code with local amendments, effective July 1, 2026 (Ordinance BC-3499). The plumbing work that doesn’t need a permit is narrow: stopping leaks, clearing stoppages, and repairs that don’t replace or rearrange valves, pipes or fixtures. Once defective concealed pipe has to be removed and replaced, the code treats it as new work that needs a permit and inspection. Replacing a water heater falls outside that exemption, so it needs a permit and an inspection. For true emergencies, Overland Park’s code lets the repair happen first: the permit application is due within the next working business day.
Olathe’s residential code amendments use the same exemption list (Olathe Municipal Code 15.04.080). Lenexa lists water heater replacement among the projects that require a building permit, applied for through the city’s online portal (City of Lenexa). In unincorporated areas around Stilwell, permits come from Johnson County Building Codes.
The same ordinance requires anyone pulling a permit to hold a current Johnson County contractor’s license. The one exception is a homeowner who lives in (or will live in) a single-family home and does the work personally. You can check any contractor on the county’s licensed contractor search.
Sources: Overland Park Ordinance BC-3499 (2024 International Codes, effective July 1, 2026); Olathe Municipal Code 15.04.080 (residential code amendments, R105.2); City of Lenexa: Remodeling Projects (permits); Johnson County Building Codes; Johnson County: search for licensed contractors. Checked October 2026.
What affects the cost
- Fuel type, capacity and efficiency of the new heater
- Location and access (attic and tight closets add time)
- Code updates the old installation was missing: venting, expansion tank, gas sediment trap, pan
- Permit fees
How it works
- Call or book. We help you stop the water first if needed, then give you an arrival window.
- Diagnose. We find the actual cause and show you what we found.
- Options before work. Repair vs replace, explained plainly. Nothing starts until you say go.
- Fixed to code. Permit and inspection handled where required, and the work area left clean.
Water Heater Replacement & Installation: common questions
Do I need a permit to replace a water heater in Overland Park?
Yes. Overland Park’s plumbing code only exempts stopping leaks, clearing stoppages and repairs that don’t replace valves, pipes or fixtures. Replacing the heater is outside that, so a permit and inspection are required. In an emergency the permit application can follow on the next working business day.
Who can pull the permit?
In Overland Park, a contractor with a current Johnson County contractor’s license, or a homeowner who lives in the single-family home and does the work personally.
How long does a water heater replacement take?
A straightforward like-for-like swap is usually done the same day. Changes in fuel type, venting or location take longer.
Why do I need an expansion tank?
When water heats, it expands. In a closed system (for example, a home with a pressure-reducing valve or check valve at the main), that extra volume has nowhere to go, so pressure spikes and the relief valve may drip. The plumbing code requires thermal expansion control in closed systems, and an expansion tank is the usual way to provide it.
What size water heater do I need?
Match the first-hour rating on the EnergyGuide label to your busiest hour of hot water use. Many 3–4 person homes do well with a 40–50 gallon gas tank; larger households, big tubs or multiple showers at once point to bigger or high-recovery models, or tankless.
Should I switch to tankless when I replace my heater?
Sometimes. It depends on gas line size, venting, how much hot water you use at once and your budget. Our tankless page explains the trade-offs.
Available in
- Overland Park: our home base in south OP.
- Olathe: Permits through the City of Olathe; sizing with your water supplier in mind.
- Lenexa: Replacement and code updates with the permit handled through Lenexa.
- Stilwell: Unincorporated: permits go through Johnson County Building Codes, not a city.
Guides for homeowners
- Do You Need a Permit to Replace a Water Heater in Overland Park?: Permits, licensing and inspections for water heater replacement in Overland Park, with the code sections behind them.
- Why Your Water Heater Relief Valve Drips: PRVs and Expansion Tanks: Why newer homes with pressure-reducing valves need working expansion tanks, and what a dripping relief valve is telling you.
- Plumbing in Stilwell: County Permits, Wells and Septic: Permits from the county, water from WaterOne, a rural district or a well, and sewer or septic depending on the address.
Related services
- Water Heater Repair: No hot water, rumbling tanks, leaks and pilot problems on gas and electric heaters.
- Water Heater Flush & Maintenance: Sediment flushes, anode checks and relief-valve tests to stretch your heater’s life.
- Tankless Water Heaters: Installs, descaling and error-code repairs, plus honest advice on tank vs tankless.
- Repiping (PEX & Copper): Partial and whole-house repipes when leaks keep coming back.
- General Plumbing Repair: The everyday fixes: shutoff valves, noisy pipes, pressure problems and more.
Get help with water heater replacement & installation
Call (913) 379-3324 or book online. Open 7 days, 7 AM–8 PM.