You can replace a water heater yourself if you have experience, the right gear, and paperwork and know your local building codes. This guide explains the risks of DIY water heater installation and highlights why hiring a professional is the wiser decision.
Why You Shouldn’t Replace a Water Heater Yourself
Installing a water heater might seem like a simple weekend project, especially if you’re comfortable handling basic home repairs. But this appliance is far more complex than it looks. Between local permit requirements, plumbing connections, and electrical or gas components, even a minor mistake can lead to safety hazards or costly property damage. Before picking up your tools, it’s worth understanding why taking the DIY route can do more harm than good.
You May Not Have the Right Permits
You must have a permit to install a water heater in most U.S. cities and states. Having a permit means the work is more likely to be done according to local building codes because it will be inspected and checked against those codes. Permits and inspections protect your home and everyone living in it.
Inspectors check that major gas or electric appliances have been installed with valid permits and adhere to relevant codes. If you install your water heater without proper documentation, you might have to redo the work or pay a penalty.
In Michigan, plumbing permits can only be obtained by qualified professionals, meaning they must be a licensed contractor and include their license number on the application.
If you want to install your own water heater, you can apply for a permit only if you have the proper credentials to perform plumbing work.
You Need Expertise in More Than Plumbing
A water heater is a complex appliance that often works with your plumbing, electrical, or gas systems. This complexity means that you must be an expert in all these fields to do the job correctly. For example, you must have electrical knowledge to safely wire a heater and experience handling gas systems to avoid accidents.
Without proper experience, you can easily make mistakes that could create safety risks or cause your new water heater to fail prematurely. Working with a reliable plumbing expert will give you peace of mind knowing that your water heater was installed correctly the first time.
You Could Void Your Warranty
You might void the manufacturer’s warranty or risk losing your homeowner’s insurance if you install a water heater yourself. Most brands require professional installation to honor the warranty. And if something goes wrong due to improper installation — like a gas leak or water damage — your insurance company might deny your claim.
You Could Choose the Wrong Size
Installing a heater that’s too small is one of many reasons households run out of hot water quickly, especially in large families. With limited hot water, you may sometimes have to endure cold showers. You may also need to run your unit consistently, meaning your home uses more energy just to keep the hot water running.
Conversely, a water heater that’s too large typically costs more to purchase, increases your home’s energy consumption, and takes up more physical space. A licensed plumber can determine the exact capacity you need so your heater runs efficiently and reliably.
You Might Install It in the Wrong Location
You can’t install a water heater anywhere you want. The location must be accessible so you can easily fix or check on the appliance. Other factors that determine where you should install your water heater include the type you choose and your local building codes. The best professional plumbers stay up to date with local building codes, which means they’ll know where to put your water heater and hook it up safely.
You Risk Damaging the Heating Elements
Before powering on your water heater, you must ensure that the heating element is completely covered by water. If you turn the power on too soon, the elements can burn out in seconds — a problem called “dry-firing.” If that happens, your heater can fail completely.
A professional installer knows how to fill the tank, connect the wiring, and test the system safely before use, preventing costly damage from the start.
You Could Use the Wrong Materials
DIY installers often use flexible plastic tubing instead of copper piping because it’s easier to work with. But these plastic pipes can expand, contract, or get damaged by heat or pests. Over time, they can cause leaks or water pressure issues.
A licensed plumber will use the correct materials and fittings, including soldered copper connections that can handle high temperatures and last for years.
Can I Install a Tankless Water Heater Myself?
While you can install your own tankless water heater, hiring a professional is the only way to ensure the safety and efficiency of the unit. Tankless water heaters need precise installation to work safely and efficiently, and even a small mistake can lead to poor performance, safety risks, or costly damage.
Unlike traditional water heaters, tankless systems heat water only when you turn on the tap. To heat water on demand, they use powerful gas burners or high-voltage electrical elements. That setup requires precise gas or electrical connections, proper venting, and the correct water line size. If any part of that system is off, the heater won’t perform as it should, or worse, it can become a safety hazard.
Here’s where homeowners often run into problems:
- Gas supply issues: Tankless water heaters often need a larger gas line than your home already has. If it’s undersized, the unit won’t get enough fuel to heat water properly.
- Venting challenges: These heaters can’t use an existing chimney. They need special venting to move exhaust safely outside. If done incorrectly, it can lead to carbon monoxide buildup.
- Setup and calibration: Tankless systems must be adjusted to your home’s water pressure, gas supply, and temperature preferences. Without the right tools, it’s easy to throw the system off balance.
While it may seem like a good way to save money upfront, a DIY tankless water heater installation can easily cost more in repairs, rework, or safety fixes down the line. Hiring a licensed plumber ensures the system is set up correctly the first time, runs efficiently, and keeps your home safe.
Get Your Water Heater Installed Safely
Randazzo Heating, Cooling, and Electrical provides licensed, code-compliant water heater installation services across Metro Detroit and Southeast Michigan. Our technicians handle permits, inspections, and all safety requirements from start to finish. Whether you choose a traditional or tankless model, we’ll size it correctly, install it safely, and ensure it performs efficiently for a long time.
Contact us to learn more or to schedule a professional water heater installation.
