By Thomas, Lead Tech, over 20 years of plumbing experience.
Prices last updated
Our tankless installs start at $750 and can run up to $4,500 for premium units with gas line upgrades, wherever we work in San Diego County and the Temecula Valley. Swapping out an old tankless unit sits close to the starting price. Converting from a tank costs more when the house needs a larger gas line, new venting and a condensate drain.
| Option | Typical installed price | What's included |
|---|---|---|
| Replacing an existing tankless unit | Starts at $750 | The new unit, installation and the permit. The gas line and venting are already there, so the job is much closer to the starting price. |
| Converting from a tank to tankless | Starts at $750, up to $4,500 | The unit, installation, the permit and removal of the old tank, plus the gas line, venting and condensate drain the conversion needs. |
| Premium units with gas line upgrades | Up to $4,500 | Higher-capacity or high-efficiency models where the gas line has to be upsized to feed them. |
| Descaling an existing tankless unit | Flat, written price before work starts | Flushing the heat exchanger with a descaling solution and cleaning the inlet screen. |
Prices are starting rates and may vary based on job complexity. Your price is flat and in writing before any work starts.
What makes a tankless install cost more or less?
The unit price matters, but the house matters more. The biggest swings come from what has to change to feed and vent a tankless heater.
- Gas line size
- A gas tankless heater draws far more gas at full fire than a tank does. If the line from the meter is too small, it has to be upsized, and that is often the largest part of a conversion.
- Venting
- Tankless units need their own vent, often a different type and route than the old tank's. High-efficiency models also need a condensate drain.
- Replacing tankless or converting from a tank
- Swapping an old tankless for a new one reuses the gas line, vent and mounting. A conversion builds those from scratch.
- Size of the unit
- A tankless heater is sized by how many fixtures run hot at the same time. A unit for two showers at once costs more than one for a single shower.
- Location
- An exterior wall in the garage is the simplest spot. Moving the heater, or mounting it where the vent run is long, adds labor.
- Permit
- Every install is permitted, and the permit is in the written price. In the City of San Diego, tankless installs do not go through the simple no-plan permit that covers tank replacements, so the permit path is different.
- Expansion control
- A system with a check valve, backflow preventer or pressure regulator needs an expansion tank or a similar device under the California Plumbing Code. We check for it at the assessment.
What is in the written price for a tankless install, and what would change it?
Included in the written price
- The tankless unit
- Installation labor and startup
- The permit and the inspection
- Venting and a condensate drain where the model needs one
- Removal and disposal of the old heater
- A one-year labor warranty on the installation, plus the manufacturer warranty on the unit
What would change it, before work starts
- A gas line upsize, found when we measure the line and the load before we price the job.
- Moving the heater to a new spot, or a long vent route.
- A different unit size than the one quoted, if you decide you need more capacity.
- Anything found when the old heater comes out, shown to you and priced before we continue.
Is tankless worth the higher price?
It depends on how you use hot water. A tankless heater does not run out the way a tank does, and it frees up floor space. In return it costs more to install, especially as a conversion, and it needs regular descaling in hard water.
If your current tank is fine and you are happy with it, a tank-for-tank swap is the lower number. If you are tired of cold showers at the end of a busy morning, or you want the garage space back, tankless is worth pricing. Our water heater replacement cost guide has the tank side.
Why does hard water matter for a tankless heater?
Scale forms on the heat exchanger, the part that heats the water as it passes through. As it builds up, the unit works harder and can shut itself down. That is why tankless heaters on hard water need regular descaling.
Most of the water we work with is hard or very hard: the City of San Diego's plants average 237 to 243 mg/L, and Rancho California Water District's imported water 230 mg/L. A water softener ahead of the heater cuts the scale.
Should I repair or replace an old tankless unit?
A unit throwing error codes or shutting down is often a scaled heat exchanger, a dirty inlet screen or a sensor, and descaling or a part can bring it back. We diagnose it before recommending a new one.
When the heat exchanger itself has failed, or parts for the model are no longer available, replacement is the better call, and it costs less than the original conversion because the gas line and vent are already there.
How do I compare tankless quotes and avoid surprise charges?
Tankless quotes vary more than tank quotes, so make each one spell out the same items.
- Did you measure my gas line and the total gas load, and is any upsize included?
- Is the venting included, and what type is it?
- Does this model need a condensate drain, and is it included?
- Is the permit included?
- What size unit is this, and how many showers can it run at once?
- What labor warranty comes with the install, and what does the manufacturer require to keep its warranty?
Tankless Water Heater cost questions
How much does a tankless water heater cost installed?
Tankless installation starts at $750 and can run up to $4,500 for premium units with gas line upgrades, in San Diego County and the Temecula Valley. Replacing an existing tankless unit is much closer to the starting price.
Why does converting from a tank cost more?
A conversion usually needs a larger gas line, dedicated venting and, on high-efficiency units, a condensate drain. A tank already has its own gas line and vent, but they are sized for a tank.
Do I need a bigger gas line for tankless?
Often, yes. We measure the line and add up every gas appliance on it before we price the job, so you know before you agree to anything.
Does a tankless heater need maintenance?
Yes. In hard water it needs regular descaling to keep the heat exchanger clear. Skipping it is the most common reason we see tankless units fail early.
Do you need a permit for a tankless install?
Yes, and we pull it. In the City of San Diego, tankless installs are not covered by the simple no-plan permit used for tank replacements, so the permit path is different. The permit is in the written price either way.
Is there a discount for upgrading to tankless?
Current offers, including any tank-to-tankless offer, are on our specials page with their terms.
Want your exact price?
Call (858) 330-2881, 8:00 AM to 10:00 PM, 7 days a week. You get a flat, written price before any work starts.
Call (858) 330-2881Related
- Tankless water heater installation and repair
- Tankless Water Heater Installation & Repair in La Mesa
- Tankless Water Heater Installation & Repair in Temecula
- Water heater replacement cost guide
- Gas line installation and repair
- Water heater guide
- How our pricing and guarantee work
- All plumbing cost guides
- About Thomas
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