Tankless Water Heaters in Longmont, CO
Endless hot water, a fraction of the footprint, and no tank waiting to leak. M&M installs, services and descales tankless water heaters across the Front Range.
Hot Water on Demand, Built for Colorado
A tankless water heater does not store hot water. It heats it the moment you open a tap, passing cold water across a powerful gas burner or electric element and sending it on its way at the temperature you set. Because nothing sits in a tank cooling off all day, there is no standby heat loss, and because the unit mounts on a wall, you get your floor space back. Run the shower, the dishwasher and the washing machine in a row and the hot water simply keeps coming.
Two local details matter. First, Longmont groundwater arrives cold in winter, so a tankless unit here needs to raise the temperature a lot more than one in Arizona. We size for flow rate and that temperature rise together, so your system keeps up in February, not just July. Second, hard Front Range water leaves scale on the heat exchanger. An annual descaling flush keeps the unit efficient and is the single best thing you can do for its lifespan.
M&M Heating, Cooling, Plumbing & Electrical has been family-owned in Longmont since 1996. Our licensed plumbers handle new tankless installation, conversions from tank water heaters including gas line and venting upgrades, repair of all makes and models, and annual maintenance. Weighing tank versus tankless? Our water heater replacement page lays out the trade-offs, or ask us during your free in-home estimate.
Tankless Water Heater Services in Longmont
Everything a tankless unit needs over its life, from the first day to year fifteen.
New Tankless Installation
Sized for your fixtures and Colorado's winter inlet temperatures, installed with proper venting, condensate handling and gas supply so it performs the way the brochure promised.
- Flow rate and temperature rise calculations
- Gas and electric models
- Free in-home estimate
- One Year Test Drive on new installs
Tank-to-Tankless Conversion
Switching from a tank often means a larger gas line, new venting and relocated water connections. We handle the whole conversion and haul the old tank away.
- Gas line sizing and upgrades
- Direct vent or power vent setup
- Wall-mount placement to free up space
Annual Descaling Flush
Hard water coats the heat exchanger with mineral scale, which reduces efficiency and triggers error codes. A yearly vinegar or descaler flush through the service valves keeps it clean.
- Service valve flush and cleaning
- Inlet filter and condensate check
- Combustion and venting inspection
Error Codes & Ignition Failures
A code on the display usually points to ignition, flame sensing, flow detection, venting or scale. We read it, test the component and fix the actual cause.
Cold-Water Sandwich or Lukewarm Output
Brief bursts of cold mid-shower, or water that never gets quite hot enough, can come from scale, an undersized unit or a flow issue. We find out which before recommending anything.
Freeze Protection & Winter Prep
Tankless units have built-in freeze protection, but it only works with power on. Outdoor and garage installs in Longmont need the right placement, insulation and backup plan for cold snaps.
The M&M Difference
Tankless done by plumbers who size for altitude, cold inlet water and hard water.
Sized for Real Colorado Conditions
We calculate gallons per minute and winter temperature rise together, and account for altitude derating, so your tankless keeps up when it is below zero outside.
Gas, Venting & Condensate Done Right
Tankless units are demanding on fuel supply and venting. Our licensed plumbers size the gas line, install code-compliant venting and route condensate so the system runs safely.
Maintenance That Protects the Investment
Annual descaling is where a tankless earns its long lifespan on hard water. We flush, inspect and clean the unit so small scale problems never become big repairs.
One Year Test Drive
Not happy with your new tankless in the first year, for any reason? We make it right, up to exchanging the equipment or removing it and refunding in full. Conditions may apply.
Our 4-Step Process
A clear path from estimate to endless hot water.
Free In-Home Estimate
We count the fixtures you want to run at once, check your gas service, venting options and water hardness, and talk through whether tankless is the right fit for your home.
Size & Quote
You get a unit sized for your peak demand and Longmont's cold inlet water, along with upfront pricing. Financing is available, and we will mention any utility rebates worth asking about.
Install & Commission
Our licensed plumbers mount the unit, run gas, venting and condensate, install isolation valves for future flushing, and set the output temperature to your preference.
Test & Teach
We verify flow and temperature at the farthest fixture, show you the display and basic settings, and set a reminder for your first annual descaling service.
Tankless Water Heater Questions, Answered
Will a tankless water heater keep up in a Longmont winter?
Yes, if it is sized correctly. Incoming water is much colder in winter, so the unit has to work harder to reach shower temperature, and altitude slightly reduces gas burner output. We size for your peak flow at winter inlet temperatures rather than the summer best case. An undersized unit is the most common reason homeowners are disappointed with tankless, and it is entirely avoidable.
How often does a tankless water heater need to be flushed?
On Front Range water, plan on once a year. Scale builds on the heat exchanger and gradually reduces efficiency, raises the chance of error codes and shortens the unit's life. The flush circulates a descaling solution through isolation valves for about an hour. If your home has a water softener, the interval can sometimes stretch, but an annual checkup is still a good habit.
Can I replace my tank water heater with a tankless?
Usually, yes. Most conversions need a larger gas line, new venting and some re-plumbing because the tankless mounts on a wall rather than sitting on the floor. Electric tankless models require substantial electrical capacity, which not every panel can supply. During the free in-home estimate we check all of this and give you a complete, upfront price for the conversion.
What is the cold-water sandwich, and can it be fixed?
It is the brief burst of cool water you feel when hot water left in the pipes from a previous use runs out before the tankless fires back up. It is normal in short bursts. If it is frequent or long, a small buffer tank, a recirculation setup or adjusting the minimum flow can smooth it out. Scale on the heat exchanger can make it worse, so a flush is often step one.
How long do tankless water heaters last?
With regular descaling, many tankless units deliver 15 to 20 years of service, which is roughly double what most tank heaters manage. Hard water without maintenance is what cuts that short. Because the heat exchanger and many components are serviceable, a well-cared-for tankless is often repaired rather than replaced well into its second decade.
Do you repair tankless units you did not install?
Absolutely. Our plumbers work on tankless water heaters from all major manufacturers regardless of who installed them. Bring us the error code if you have one and we will come prepared. If the unit was never flushed, we will usually recommend a descaling as part of the repair, since scale is behind a large share of tankless complaints.
Ready for Endless Hot Water in Longmont?
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Call (720) 608-3973Tankless Water Heater Service Across the Front Range
Proudly serving Longmont, CO and surrounding communities.
Primary Service Area
- Longmont, CO
- Erie, CO
- Frederick, CO
- Firestone, CO
- Dacono, CO
Extended Area
- Mead, CO
- Johnstown, CO
- Berthoud, CO
- Niwot, CO
- Gunbarrel, CO
Also Serving
- Lafayette, CO
- Louisville, CO
- Superior, CO
