Licensed Maryland HVACR contractor · 41 years in Montgomery County 24/7 emergency service
Poteete HVAC · since 1985

Maryland · Water heating · 24/7 emergency

Tankless Water Heater Repair in Maryland

Error codes, scaling, ignition faults and flow problems on all major tankless brands — with descaling that restores the output you paid for.

Tankless water heaters announce their problems with error codes, which is a gift if the technician knows what the codes mean. A 10-series code on one brand is an air supply or exhaust blockage; a 11 is ignition failure; a 12 is flame loss; a 79x family points at the heat exchanger. We work on the units common in this market and we read the fault history in the controller rather than guessing from symptoms.

By far the most common underlying problem in Maryland is scale. Hard water and well water deposit calcium on the heat exchanger, which reduces heat transfer, raises exhaust temperature, throttles flow and eventually trips the unit into a hard fault. A descale often restores full output on a unit the homeowner had already written off. When it does not, we test the exchanger and tell you plainly whether the repair is worth it.

Where we work
Tankless water heater flow Cold water entering a flow sensor, passing through a modulating burner and heat exchanger, exiting hot on demand, with isolation service valves and a condensate drain. Cold supply Flow sensor Hot, on demand Gas — up to 199,000 BTU Modulating heat exchanger Service valves Condensate
Nothing heats until a tap opens. The two things that decide whether a tankless unit performs are the gas supply — often two or three times what the old tank drew — and the descaling interval. Isolation valves are standard on our installations because without them, that annual service becomes a plumbing project.

Scope

What the job actually includes

  • Controller fault history read and interpreted, not just the current code
  • Full descaling with circulation pump and food-grade solution
  • Inlet filter screen, flow sensor and cold-water inlet cleaning
  • Igniter, flame rod, gas valve and fan diagnosis
  • Combustion analysis and vent inspection for blockage or recirculation
  • Gas supply pressure test under full fire — a common cause of intermittent faults
  • Isolation valve retrofit if the original installer omitted them

Maryland specifics

Code, permits and rebates

Repairs do not require a permit in Montgomery County, but replacing the unit or altering gas piping does. Water chemistry is the dominant local factor: WSSC-supplied homes in Silver Spring, Takoma Park and Bethesda have moderately hard water that calls for descaling roughly annually, while private wells in Olney, Glen Hills and outer Potomac can require it twice a year. If a tankless unit in a well-water home has never been descaled, expect the first service to recover a substantial amount of lost output.

Licensing

MD HVACR Contractor License #01-XXXXX. All refrigerant handling is performed by EPA Section 608 certified technicians, and equipment replacement is permitted and inspected through the county.

Process

How we run a tankless repair job

  1. Read the fault history

    Most units store recent error codes. That history tells us whether we are chasing an intermittent gas supply problem, a venting issue in high wind, or a progressive scaling failure.

  2. Verify gas and venting under load

    Many intermittent tankless faults are an undersized gas line that holds pressure at idle and drops when the unit fires at full rate. We measure at the manifold while it fires, which is the only way to see it.

  3. Descale and clean

    Circulated descaling solution through the heat exchanger, inlet screen cleaned, flow sensor checked. Output measured before and after so you can see what it recovered.

  4. Test and document

    Flow rate and temperature rise verified at a fixture, combustion checked, and the maintenance interval set for your water quality rather than a generic annual default.

Pricing

What moves the price

We do not publish a single number, because a number without your house attached to it is marketing rather than information. These are the variables that actually decide what a job costs, and we itemise all of them in writing before any work begins.

Descaling versus component failure

A descaling service is routine maintenance pricing. A failed heat exchanger, gas valve or control board on an out-of-warranty unit is a much larger number, and on a unit past twelve years often points to replacement.

Missing isolation valves

If the original installer skipped service valves, descaling requires cutting them in first. It is worth doing once and never paying for again.

Warranty status

Most tankless heat exchangers carry 12- to 15-year warranties, but coverage frequently depends on documented annual maintenance and a registered installation. We check your registration and warranty position before quoting parts.

Questions

Tankless Water Heater Repair questions

My tankless unit shows an error code and shuts down. What now?
Note the code before resetting — it is the most useful diagnostic information available, and clearing it without recording it makes the visit longer. Then check that the vent termination outside is not blocked by snow, leaves or a nest, since air supply and exhaust faults are the most common family of codes and the easiest to resolve.
How often does a tankless heater need descaling?
On WSSC water in Montgomery County, about once a year. On private well water with high hardness, every six months. If the unit has isolation valves, it is a quick service; if not, we fit them during the first visit so subsequent ones are simple.
The water is not as hot as it used to be.
Declining output on an aging tankless unit is the signature of scale on the heat exchanger reducing heat transfer. It can also be a partially clogged inlet filter or a failing flow sensor under-reporting demand. A descale and filter clean resolves the majority of these calls.
Do you work on all brands?
We service the major residential tankless brands installed across this market, including condensing and non-condensing models. Parts availability varies by brand and age, and we will tell you at diagnosis whether a part is stocked locally or has to be ordered.

Talk to a technician

Tell us what the house is doing.

Describe the problem and we will tell you what it usually means, what it typically costs to diagnose, and when we can be there. No obligation, no scripted sales call.

Call (301) 555-0182 Request a quote

Mon–Fri 7:00am–6:00pm · Saturday 8:00am–2:00pm · 24/7 emergency service