Tankless water heater installation in Los Angeles, sized for your gas line and water

A typical tank heater burner uses around 40,000 BTU per hour. Whole-house tankless units fire at several times that rate, so the half-inch gas line feeding most old tanks cannot carry enough gas. An undersized line causes the unit to throw error codes, lose temperature during showers or shut down entirely.

We measure the total length of gas pipe from the meter, add up every appliance on the system and size a new line to carry the combined load. That often means running a three-quarter-inch or one-inch line from the meter to the heater. Sometimes the meter itself needs a larger regulator, which is coordinated with SoCalGas. Our gas line installation work covers that run when it is needed.

Non-condensing tankless heaters send hot exhaust out through stainless steel venting. They cost less to buy but more to vent, since the flue material is expensive and the vent runs have strict limits on length and turns.

Condensing units pull extra heat from the exhaust, which cools it enough to vent through PVC or polypropylene pipe. They are more efficient and easier to vent through a side wall, but they produce acidic condensate that must drain to a proper point, usually through a neutralizer. Most of the units we install in Los Angeles homes are condensing models for that reason.

Both types need clearance from windows, doors and property lines for the vent termination. On tight side yards between houses, that clearance can decide where the unit goes.

• Non-condensing: lower unit price, stainless venting
• Condensing: higher efficiency, plastic venting
• Condensing: needs a condensate drain and neutralizer
• Both: vent clearances from openings and lot lines

Tankless heaters push water through a narrow heat exchanger at high temperature, and hard water leaves scale on those passages quickly. Scale buildup reduces heat transfer, triggers error codes and can crack the exchanger over time. Every unit we install gets a set of isolation valves with service ports so the heat exchanger can be flushed with a descaling solution.

Plan on descaling once a year in most of the region, more often where the water is especially hard or no softener is installed. Our tankless descaling service handles that maintenance. A scale-reduction cartridge on the cold inlet or a softener for the whole house can stretch the time between flushes.

Tankless heaters deliver continuous hot water, but they do not deliver it faster to a far bathroom. The water sitting in the pipe still has to run out before hot arrives. A unit with a built-in recirculation pump, or a separate recirculation pump, solves that wait.

Very low flows, such as a single bathroom faucet barely open, can fall below the activation threshold on some units. Modern heaters have lowered that threshold, but it is still worth knowing. If you are comparing tankless with a heat pump tank, our water heater comparison guide lays out the tradeoffs in plain terms.