Running out of hot water mid-shower
We size a tankless unit to your fixture count and Littleton's cold winter inlet water, so you get continuous hot water at 120 degrees no matter how many people are showering.
Endless hot water, lower gas bills, and a clean, code-correct install
Tankless Water Heater Installation Littleton CO you can count on
Tankless Water Heater Installation Littleton CO homeowners call us for is a same-week job, not a two-week ordeal. We size the unit to your fixtures, run the gas and venting to code, and have hot water running the same day in most homes. If your old tank is rusting out or you are tired of running out of hot water mid-shower, we handle the whole swap from permit to first faucet test.
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About this service
Tankless Water Heater Installation Littleton CO, done right
Tankless Water Heater Installation Littleton CO is the trade of replacing a storage tank with a wall-mounted heat exchanger that heats water only when a fixture calls for it. We mount the unit, run a dedicated gas line sized to its BTU rating, install stainless or PVC venting, and pipe the hot and cold lines through dielectric unions so you do not get galvanic corrosion at the connections. A typical residential unit fires at 150,000 to 199,000 BTU and delivers 8 to 11 gallons per minute, which is enough to run two showers and a dishwasher at once.
Most Littleton homes we walk into are running a 40- or 50-gallon tank that is 10 to 15 years old, sitting in a basement or garage corner with a puddle forming under it. When you call us for on demand water heater installation Littleton, we look at your incoming water temperature, which drops to about 45 degrees in January, and size the unit so it still delivers 120 degrees at the tap on the coldest morning of the year. If you have been searching for on demand water heater installation near me Littleton CO, we cover the whole city and Arapahoe County.
- ✓ Endless hot water
- ✓ Lower gas bills
- ✓ 15 to 20 year lifespan
- ✓ Frees up floor space
What's included
What our tankless installation includes
Every install we do covers the full scope: the unit, the gas connection, the venting, the water lines, the permit, and the first test. We do not hand you a unit and leave you to find a plumber for the rest. Here is what is in the standard job.
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Unit and mounting
We supply and hang the tankless unit, mount the bracket to studs or blocking, and set the unit level. We confirm clearance to combustibles and access for future service before we drill a single hole.
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Gas line and shutoff
We run or upsize the gas line to match the unit's BTU rating, install a new gas shutoff, and pressure-test the connection. If your meter cannot feed a 199,000 BTU unit, we tell you before we start.
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Venting to code
Stainless or PVC venting, run to manufacturer spec and current code. We route it to an exterior wall or through the roof, seal the penetration, and confirm the condensate drain is pitched and draining.
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Water lines and filter
Hot and cold lines piped through dielectric unions, with a sediment filter on the cold inlet. We purge the lines, check every joint with a pressure gauge, and confirm no leaks before we fire the unit.
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Permit and inspection
We pull the plumbing and gas permit and coordinate the inspection with Arapahoe County. You get the sign-off paperwork and the manufacturer warranty registration when we are done.
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Walkthrough and setup
We set the outlet temperature to 120 degrees, test every hot fixture in the house, and show you how to read the display, clean the filter, and flush the unit. You leave with our number and a service schedule.
How it works
How our installation process works
01
Call and sizing
You call (720) 698-9814 and tell us what you have and what you want. We ask about bathroom count, fixtures, and whether you have a gas line near the install spot. We give you a ballpark range on the phone and book a visit, usually same day or next day.
02
On-site assessment
A licensed plumber walks your mechanical room, checks the gas meter capacity, measures the vent run, and reads your incoming water temperature. We confirm the unit size, the venting route, and where the condensate will drain. This takes 30 to 45 minutes and you get a firm price before we touch anything.
03
Removal and prep
We shut off the gas and water, drain the old tank, and haul it out. We cap the old connections, patch the flue if needed, and mount the new bracket on the wall. If the gas line needs upsizing to feed a 199,000 BTU unit, we run that now, along with a sediment filter on the cold inlet.
04
Install and commission
We hang the unit, connect the gas with a new shutoff, run the venting to code, and pipe the hot and cold lines through dielectric unions. Then we purge the lines, check for leaks with a pressure gauge, and fire the unit. We set the outlet temperature to 120 degrees and test every hot fixture in the house.
05
Walkthrough and paperwork
We show you how to read the error codes, where the filter is, and how to flush the unit. You get the manufacturer warranty card, the permit sign-off, and our number for anything that comes up. If you want a descaling schedule, we will set one up before we leave.
Tools & methods
Tools and methods we use
Purpose-built equipment, used by trained technicians — so the job is done accurately the first time.
Tube cutter and soldering torch
For clean copper cuts and leak-free soldered joints on the hot and cold lines. We deburr every cut and pressure-test before we close up.
Pipe wrench and dielectric unions
To make up the gas and water connections without over-torquing. Dielectric unions stop galvanic corrosion where copper meets the unit's steel ports.
Multimeter and pressure gauge
To verify gas pressure at the inlet, check the flame sensor signal, and confirm no leaks on the water side before we fire the unit.
Descaling pump
For annual heat exchanger flushes. Littleton's hard water leaves scale that shortens unit life, and a vinegar flush every year keeps it clean.
Inspection camera
To look inside walls and chases for vent routes and gas line paths without tearing out drywall. Saves time and keeps your finished space intact.
Water heater element wrench
For tank units we service or replace. We keep one on the truck for same-day repairs when a customer decides to repair instead of going tankless.
Real results
Before and after.
12-year-old tank to Navien condensing unit
Before
A 50-gallon tank in a Downtown Littleton basement, 12 years old, rusting at the base with a slow drip into the pan. The family of four ran out of hot water every morning and the gas bill spiked each winter.
After
We installed a Navien condensing unit on the wall, ran a new 3/4-inch gas line, and vented through the side wall with PVC. Hot water runs continuously at 120 degrees and their winter gas bill dropped about 25 percent.
Undersized tankless swap in Columbine Hills
Before
A homeowner had a 7 GPM tankless unit installed by a previous contractor. In winter, two showers at once dropped the temperature to lukewarm. The unit was undersized for Littleton's cold inlet water.
After
We replaced it with a 199,000 BTU condensing unit sized for 45-degree inlet water, reused the existing venting where code allowed, and upsized the gas line. Now both showers run hot at the same time, even in January.
Garage tank to wall-mounted unit in 80123
Before
A 40-gallon tank in a Littleton garage, taking up the corner and blocking access to the furnace. The tank was 11 years old and the homeowner wanted the space back before it failed.
After
We mounted a Rheem tankless unit on the garage wall, ran the venting and gas line, and reclaimed about 6 square feet of floor space. Install took one day and the homeowner had hot water by 4 p.m.
Problems we solve
Problems a tankless install solves for good
If any of these sound familiar, a tankless unit is the fix. We see these calls every week across Littleton, especially once the temperature drops.
Ask a pro →↗
Rusty water or a puddle under the tank
We pull the failing tank, inspect the pan and drain, and install a wall-mounted tankless unit with no standing water to corrode. You get the space back and the leak risk goes away.
High gas bills every winter
A tankless unit only fires when a faucet opens. Most Littleton customers see 20 to 30 percent off the water-heating portion of their gas bill, which adds up over a Colorado winter.
No room for a new tank
A tankless unit mounts on the wall and takes about 2 square feet. We have installed them in closets, crawlspaces, and garage corners where a tank would never fit.
Proof you can check
Licensed, insured, and warrantied
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State Plumbing LicenseColorado Department of Regulatory Agencies
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NATE CertificationNorth American Technician Excellence
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EPA 608 CertificationU.S. Environmental Protection Agency
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OSHA 10 CertificationOccupational Safety and Health Administration
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Manufacturer TrainingNavien, Rinnai, and Noritz
Most residential installs in Littleton run $3,200 to $6,500 in 2026, depending on unit size, venting route, and whether the gas line needs upsizing. A straightforward swap with an existing vent path sits at the low end. Long vent runs, a new gas line from the meter, or a condensing unit with PVC venting push it higher. We give you a firm number after the on-site assessment.
The best service is the one that sizes the unit to your actual water temperature and fixtures, pulls the permit, and stands behind the work. We are a state-licensed plumbing contractor with manufacturer training on Navien, Rinnai, and Noritz. Ask any installer for their license, their permit process, and their warranty terms before you book.
Yes. If your tank fails at 2 a.m. or on a holiday, call (720) 698-9814 and we will get a plumber out. Full installs usually wait for daylight so we can pull the permit, but we can isolate the leak, shut off the water, and get you back online. Emergency calls across Littleton, CO 80120 and 80123 are common in winter.
A standard swap takes 4 to 8 hours, so most jobs are done in a single day. If we need to run a new gas line, cut a new vent path through the roof, or relocate the unit, plan on two days. We tell you the timeline during the assessment so you can plan around it.
More services
Related Services
Water Heater RepairIf your tank is still under 10 years old and the problem is a heating element, thermostat, or T&P valve, repair is often the smarter call. We diagnose it first and tell you honestly whether a fix or a swap makes more sense for your Littleton home.Explore →
Water Heater ReplacementNot ready to go tankless? We replace traditional tank units in the same day, haul the old one out, and bring everything up to current code. Many customers start here and move to tankless when the next replacement comes around.Explore →
Water Heater InstallationNew build, remodel, or a home that never had a water heater? We handle full installations from scratch, including gas line, venting, expansion tank, and permit. This is the same crew that does our tankless work.Explore →
Water Heater MaintenanceTankless units need annual descaling to keep the heat exchanger under warranty. We flush the unit, clean the sediment filter, and check the gas pressure. It takes about an hour and adds years to the unit's life.Explore → Ready when you are
Book your Tankless Water Heater Installation Littleton CO today
Call (720) 698-9814 and we will size the unit, quote the job, and get you on the schedule. Licensed, insured, and warrantied work across Littleton and Arapahoe County. One call and you are done running out of hot water.
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Call (720) 698-9814 any time, day or night, and a real person picks up. For non-emergency work, we schedule same-day or next-day appointments across Littleton and the surrounding ZIP codes. Tell us what's going on with your water heater and we'll get a licensed plumber headed your way.
Call anytime(720) 698-9814Email the officeinfo@littletonwaterheaterrepair.com
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