Most water heater work is a straight swap. Installation is what happens when something changes: a unit moves out of a hallway closet, a garage conversion displaces it, a family chooses tankless, or an older home finally gets a heat pump unit. Each of those carries decisions a simple swap never raises.
What counts as a new installation
- Relocation. Moving the heater to a different room or out of the living space entirely.
- Fuel change. Gas to electric, electric to gas, or natural gas to propane where supply changes.
- Type change. Tank to tankless, or tank to heat pump.
- Additions. A second heater for an addition, an accessory unit or a far wing of the house.
- New construction and major remodels. Where the utility space is being designed from scratch.
In each case, the new heater needs a supply of gas or electricity sized for it, water lines, a relief-valve discharge route, venting if it burns fuel, the correct clearances and securing against seismic movement.
Choosing the location
The best spot balances four things. It should be reasonably close to the bathrooms and kitchen, so hot water arrives without a long wait. It needs room for a technician to work on it later. It needs a safe route for venting and discharge. And a leak there should cause as little damage as possible.
That's why so many California homes put the heater in the garage: slab floor, open access, short vent runs. Exterior closets on an outside wall are the other common answer in tract housing, though they expose the unit to sun and heat. In older northern homes the basement or a utility closet may be the only practical place, and access becomes the driving factor.
California considerations
Strapping and bracing. A new installation is secured to the structure from day one. Requirements vary by jurisdiction; the installer confirms what applies and checks that the wall framing at the new location can take the fasteners.
Water quality. In hard-water areas, a new installation is the easiest moment to add isolation valves for future tankless descaling, or to plan around a softener. Hardness varies by district; your water provider can tell you about your supply.
Winter inlet temperature. Tankless and heat pump units are especially sensitive to how cold incoming water gets. In the Bay Area, the valley and the foothills, sizing should assume a cold winter morning.
Heat pump suitability. Heat pump water heaters draw heat from surrounding air. A roomy garage in a mild climate is a good fit; a tight interior closet or a garage that gets very cold in winter often isn't. Programs and requirements around them exist, vary by utility and jurisdiction, and change, so confirm current details with your own utility.
We'll connect you with an installer who works with both.
Gas, power and venting
A gas tank typically needs a gas line and a vent. A tankless gas unit usually needs a larger gas supply and a specific kind of venting, often through a wall. An electric tank needs a dedicated circuit of the right capacity. A heat pump unit needs a circuit, space and a condensate drain. Propane units need to be configured for propane.
These are not details to guess at, and we don't publish venting or gas sizing rules because they depend on the manufacturer and the jurisdiction. The installer works them out for your specific unit and home.
Not a DIY project
Gas connections, electrical circuits, venting and the relief valve all carry real risk if done wrong. This site doesn't give instructions for any of them. If you smell gas at any point, leave the building and call your gas utility and 911 from outside.
How an installation is carried out
It starts with a site visit: the installer looks at the proposed location, measures, checks the existing gas or electrical capacity and the vent route, and asks how the household uses hot water. From that comes a written scope and price covering the unit, any supply or venting work, strapping, accessories and removal of anything old.
On the day, supply work usually comes first, then the unit is mounted or set in place and secured, water and discharge lines are run, venting is installed, and the heater is connected, filled, purged of air and started. The installer checks operation, confirms there are no leaks, and walks you through the unit's basic care, including any descaling schedule for tankless.
What drives the cost
| Factor | Why it matters |
|---|---|
| Distance moved | New water, gas or electrical runs add materials and labor. |
| Supply upgrades | A larger gas line or a new circuit can be a significant part of the job. |
| Venting | New penetrations through walls or roofs, or a change of vent type. |
| Unit type | Tankless and heat pump units cost more than a standard tank. |
| Finishing work | Patching, closet modifications or platforms where the location needs them. |
How long it takes
A simple new tank in a prepared location can be finished in a day. Relocations and conversions involving new gas lines, circuits or venting commonly take longer, and some need a unit or materials ordered first. Any permit that applies to your job may also affect scheduling. The installer will set out a realistic plan with you.
Understand what your home needs before you commit to anything.
Installation questions
A replacement puts a similar unit where the old one was, reusing the existing gas or power, water and vent connections. An installation involves something new: a different location, a different fuel, a different type such as tankless or heat pump, or a heater where there wasn't one before. That usually means extra work on supply, venting or both.
Close to where most hot water is used, with room for service access, correct clearances and a safe route for venting and any relief-valve discharge. In much of California that's the garage. In older homes it may be a basement or utility closet. Heat pump units also need enough surrounding air. The installer weighs these against your home's layout.
Often, and it can free up a closet and put a leak somewhere less damaging. It means new water lines, a new gas run or circuit, new venting and strapping at the new location. Long pipe runs can also mean a longer wait for hot water at distant taps, so the installer may talk to you about that too.
Frequently. Tankless gas units draw a lot of gas at full fire, and many existing lines were sized for a tank heater. The installer checks the gas supply against the unit's needs and the rest of the home's gas appliances. If the line needs upgrading, that belongs in the quote, not as a surprise on the day.
Space and air around it, a suitable electrical circuit and a way to drain condensate. It also cools the room it's in slightly, which suits a warm garage but not a small closet. Utility programs related to heat pumps exist but vary by utility and change, so check with your own utility for current details.
Yes. Any water heater installed in California should be secured to the structure against seismic movement. How that's done depends on the jurisdiction and the location. The installer confirms what applies at your address and builds it into the plan and price.
It depends on your plumbing. Where a home's water system is closed, for example because of a check valve or pressure regulator, heating water has nowhere to expand, and an expansion tank gives it somewhere to go. The installer checks your system and explains whether one is needed and why.
If the current heater still works, planning a little ahead lets you compare options, check fit, sort out any gas or electrical work and choose the right unit without pressure. A call now costs nothing and can help you understand what your home would need.