Two very different hookups
A gas tankless unit needs a gas line large enough for its burner, a vent to the outdoors, and an ordinary outlet for its controls. An electric whole-house tankless unit needs no vent or gas line, but it draws a large amount of current, usually on more than one dedicated circuit.
Many Fullerton homes built in the 1950s through the 1970s have electrical panels sized for the loads of that era. Adding a whole-house electric tankless unit can require panel capacity those homes do not have. On the gas side, the same homes often have a line sized for a tank. Either path may involve upgrades, so it helps to know which one your house can take more easily.
Comparison
| Factor | Gas tankless | Electric tankless |
|---|---|---|
| Main utility demand | Large gas input at full fire | Large electrical current at full use |
| Venting | Required, per manual | None |
| Typical upgrade | Larger gas line; meter review through SoCalGas | New circuits; possible panel or service upgrade |
| Condensate | Condensing models need a drain | None |
| Hard-water upkeep | Flushing the heat exchanger | Flushing and checking heating elements |
| Power outage | Most models stop without power | Stops without power |
Which way does your house lean?
- IfYou already have gas to the water heater and room for a ventThenGas tankless is usually the more common route; have the line size checked.
- IfThe panel is small and olderThenWhole-house electric tankless may need a panel or service upgrade; get an electrician's opinion early.
- IfYou only need hot water at one remote sinkThenA small point-of-use electric unit may be enough there.
- IfYou plan to move away from gas appliancesThenCompare electric tankless with other electric options, such as a heat pump water heater, before deciding.
Information to gather
- Electrical panel size and the number of open breaker spaces
- Gas line size at the water heater and the other gas appliances in the house
- Where a vent could exit if you choose gas
- Your household's peak hot water demand
- Any plans for solar, an EV charger or other large electric loads
Common questions
Is electric tankless cheaper to install?
It avoids venting and gas work, but electrical upgrades can be significant. Get both options scoped for your house.
Can a small electric unit serve one bathroom?
Point-of-use units can serve a single fixture or small bath. Ask a plumber whether one fits your situation.
Do electric tankless units need flushing too?
Hard water affects them as well. Follow the manufacturer's maintenance guidance.
General information for Fullerton, not a quote or professional advice. In an emergency, call 911.