Direct vs. Power Vent
Power venting a water heater costs about $500 to $1,000 more than a passive system. “A direct vent system brings combustion air from outside and exhausts directly to the outside of the building,” says Botelho. Direct vent heaters use two pipes—one for combustion and makeup air and the other for exhaust.
Permits
Most locations require permits to replace a water heater, typically costing $50 to $150. Check with your local requirements before you begin; some limit installation or replacement to a licensed plumber.
Adding an Expansion Tank
A water heater expansion tank costs $100 to $350 for both parts and labor. When water heats up and enters the system, it increases the pressure. The expansion tank then absorbs some of that pressure and overflow to keep pressure in the system down.
Relocating the Water Heater
Relocating a water heater means adding water lines, electrical outlets, or gas lines (if they are not preexisting in the new location). Here are the average costs of those factors:
Changing Fuel Types
Changing fuel types means running new lines to the home or expanding on what’s already there so you can change the fuel powering your water heater.
Going from gas to electric costs $500–$2,000 and involves adding a new circuit.
Going from electric to gas costs $500–$1,500 and involves adding new gas pipes.
Optional Warranties
Optional warranties run anywhere from $100 to $300. It can extend the coverage of your water heater, add free inspections if you purchase it through your plumber, and extend the protection of your investment. Some manufacturers offer a warranty, or your plumber might offer additional coverage through their shop.
Removal
Removing the water heater currently in your home costs between $100 and $500. The price will depend on your contractor’s hourly rate. If the unit is hard to access or difficult to remove, expect to pay more for removal.
DIY vs. Hiring a Plumber to Replace a Water Heater
Leave water heater installation to the pros. You’re hooking up two major utilities—water and gas or electric—to an appliance. If done incorrectly, you can cause water damage to your home, electrical system, and yourself. Hire a local plumber to install your water heater. Not only will it get done properly, but reputable, licensed plumbers warranty their work and carry insurance in case anything goes wrong.
"As a licensed plumber with nearly twenty years in the field, I've seen and repaired dozens of DIY-installed water heaters,” said Botelho. “It has long been my opinion that a knack for mechanical work is no substitute for professional training. Installing a water heater—or any plumbing appliance or fixture—is not a hobby project to be tackled on a Sunday. Any time a job involves connections to major utilities (including gas, oil, or line voltage electricity) it should be done by a licensed and trained professional."