Your tankless water heater suddenly stops heating, or produces an error code that kills hot water in the middle of a shower—and you need it running again now. J&G Heating & Air Conditioning dispatches NATE-certified technicians to diagnose and repair tankless units across Lancaster County during emergency hours (Mon–Sun, 6:00 AM–10:00 PM, after-hours fee applies). We’ve repaired hundreds of Bradford White, Rheem, and Navien systems since 1997. We know how to read error codes, test water flow sensors, verify gas and ignition, and get you back to on-demand hot water fast.
Don’t go without hot water. When you’re investing in a new central air system, the contractor matters as much as the equipment. Our experience, manufacturer certifications, and family-owned service all add up to one thing: an tankless repair done right the first time, backed by people who’ll be here for tune-ups and future maintenance when you need them.
J&G Heating & Air Conditioning provides tankless repair service across all five communities we serve in Lancaster County. Emergency service is available Mon–Sun, 6:00 AM–10:00 PM (after-hours fee applies). When your tankless unit fails, we dispatch a certified technician with the tools and parts to get you back to on-demand hot water fast.
Recognizing the early warning signs of tankless water heater problems can save you from complete system failure and costly emergency repairs. Here are the most common issues we see and what they mean.
Your thermostat is set to a higher temperature and you’ve got water running, but the unit display is dark or shows an error code instead of heating. The problem could be a weak spark at the igniter electrode, a failed ignition control module, a safety sensor preventing ignition, or a corroded gas connection. We test the spark, measure ignition voltage, check all safety sensors, and identify which component needs service.
Your tankless display shows a code like “E05” (low water flow), “E11” (flame failure), “E12” (low gas pressure), or others. Error codes are designed to shut the unit down for safety. We read the error code using manufacturer diagnostics, perform the troubleshooting steps for that specific code, and fix the underlying problem.
Water comes out lukewarm instead of hot, or temperature swings unpredictably. The problem usually stems from mineral scale inside the heat exchanger, a worn mixing valve, a failed water flow sensor, weak gas supply, or incoming water so cold that the unit can’t heat it fast enough. We descale if needed, test the mixing valve, and adjust or replace failing components.
Some tankless units use a standing pilot light rather than electronic ignition. If the pilot is out or won’t light, the main burner can’t ignite. If the pilot light flickers or looks yellow/orange instead of blue, combustion is incomplete. We clean the pilot burner, test electrode gap, verify gas pressure, and check venting for leaks.
A smell of burning, rust, or rotten eggs near the unit; a loud roaring sound during startup; a banging or vibration. A burning smell suggests carbon deposits building up, rust smell suggests internal corrosion, rotten egg smell suggests bacteria in the gas supply or water. Any of these warrants immediate inspection to prevent further damage.
Visible dripping from the unit body, a puddle beneath it, or moisture on copper tubing. Leaks from the inlet/outlet ports suggest loose compression fittings. Leaks from the unit body suggest internal corrosion or a failed seal. We locate the leak source, tighten connections if possible, or replace internal seals or components as needed.
Every tankless water heater repair we do follows the same proven process — designed to deliver accurate diagnosis, professional workmanship, and a system that performs from day one. Tap any step below to see exactly what happens.
You call or book online describing the problem—no hot water, error code, temperature swings. Our dispatch team logs your address and prioritizes emergency calls. Our technician arrives with a fully stocked truck carrying replacement igniters, gas valves, inlet filters, mixing valves, and diagnostic tools within 2–4 hours for emergency calls.
The technician examines the unit: exterior condition, venting, gas and water connections, and any visible corrosion. They turn on the system and observe startup. If an error code displays, they photograph it. They also check gauges (if equipped) and listen to ignition. This rapid visual assessment often reveals the problem: pilot out, visible gas leak, or specific error code guiding diagnosis.
If visual inspection doesn’t reveal the problem, the technician measures gas pressure and water flow. Gas pressure is tested using a calibrated gauge—low pressure signals a problem upstream at the meter or regulator. Water flow is measured at the inlet—low flow signals a clogged inlet filter or low supply pressure. Abnormal readings point directly to the root cause.
If pressure and flow are normal, the technician tests electrical components and safety sensors using a multimeter. They test spark electrode voltage, ignition module output, gas valve solenoid coil resistance, thermostat wire continuity, and flame sensor continuity. Each test narrows down which component has failed.
Once the failed component is identified, the technician decides: can this be repaired affordably, or does replacement make more economic sense? A failed inlet filter ($50 part) is always repaired. A failed control board ($300+) on a 15-year-old unit might justify replacement. They explain options, recommend the best path, and perform the repair once you approve.
The technician powers up the repaired unit and runs it through a full heating cycle. They listen for proper spark, observe flame establishment, verify the modulating burner responds to demand, measure outlet temperature and confirm it matches setpoint, and observe clean shutdown. The system runs for at least 20 minutes to confirm stability and no error codes.
If mineral scale blocked the heat exchanger, the technician performs chemical descaling. They connect a descaling pump, run food-safe solution through the heat exchanger for 45–60 minutes per manufacturer procedure, then flush the system with clean water and restart to verify normal performance.
Before leaving, you receive a walk-through on what failed, why, and how to prevent it. The technician explains error code recognition, inlet water filter replacement, descaling schedule, temperature setpoint adjustment, and what to do if the unit stops heating again.
Here are the most common tankless water heater repairs we perform and what you can expect in terms of time and cost.
Sediment and particles clog the inlet filter over time, restricting water flow and triggering error codes. Filter replacement is simple (15 minutes) and inexpensive ($30–60). Annual replacement in most areas; more often if you have a sediment-heavy water supply.
Schedule ServiceThe spark electrode creates the initial flame to light the gas burner. If the electrode corrodes or becomes misaligned, the spark weakens or fails and the unit won’t ignite. Cleaning or replacement takes 30–45 minutes. We test the electrode gap and voltage to confirm this is the problem.
Get ServiceThe gas valve modulates (controls) the gas flow to match hot water demand. If the valve solenoid fails or the valve becomes stuck, the unit won’t heat or heats inconsistently. Gas valve replacement is involved ($200–400) but necessary for system operation.
Schedule ServiceThe mixing valve (tempering valve) blends hot and cold water to prevent dangerously hot outlet water. If it fails, outlet temperature becomes unpredictable or dangerously high. Adjustment is sometimes enough; replacement ($150–250) if the valve is worn out.
Get ServiceThe flow sensor tells the unit when water is flowing (call for heat) and when flow stops (shut down). If the sensor fails, the unit may not ignite, or may overheat trying to shut down. Flow sensor replacement ($100–200) is a specialty service requiring careful calibration.
Schedule ServiceHard water minerals accumulate inside the heat exchanger, reducing efficiency and eventually blocking water flow. Professional descaling ($150–300) dissolves mineral deposits and restores normal heat transfer. Annual service in hard water areas prevents scale buildup and costly failures.
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We believe every homeowner in Lancaster County deserves access to reliable heating and cooling — regardless of budget. That’s why J&G Heating & Air Conditioning partners with trusted financing providers to offer flexible payment plans that fit your financial situation. Whether you’re replacing an aging boiler, upgrading to a high-efficiency air conditioning system, installing a high-efficiency heat pump, or investing in a new generator system, financing allows you to enjoy the comfort you need today while spreading payments over time.
Our team will walk you through every available option during your free estimate, helping you understand monthly payment amounts, interest rates, and approval requirements. We want the financial side of your project to feel just as comfortable as the temperature in your home.
As an authorized Wells Fargo financing partner, J&G Heating & Air Conditioning offers a range of credit options to help you manage the cost of your new heating or cooling system. With competitive rates and flexible terms, qualifying homeowners can enjoy convenient monthly payments that fit comfortably into their household budget.
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Through our partnership with PowerPay, we provide another trusted financing pathway for Lancaster County homeowners ready to upgrade their home comfort. PowerPay’s streamlined application process and flexible repayment plans make it easy to get started on your project without delay.
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GoodLeap offers flexible financing options and competitive rates, making it easy for homeowners to invest in high-efficiency heating, cooling, and generator systems. With a simple application process and a variety of repayment terms, upgrading your home comfort doesn’t have to mean a large upfront cost.
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When you join one of our maintenance programs, you’ll receive scheduled tune-ups performed by our NATE-certified technicians who know your system inside and out. We’ll clean critical components, check refrigerant levels, inspect electrical connections, test safety controls, and ensure everything is operating as it should.
Regular maintenance doesn’t just prevent breakdowns — it also helps lower your energy bills and protects your manufacturer warranty coverage. It’s one of the smartest investments you can make in your home’s comfort and your family’s safety.
A broken tankless unit means no hot water—a serious inconvenience that demands fast, professional service. J&G Heating & Air Conditioning has repaired hundreds of tankless systems across Lancaster County for nearly 30 years. When your unit fails, we arrive fast, diagnose accurately, and fix it right the first time.
Professional diagnosis saves money. We test before we fix. When repair makes sense, we do it affordably and fast. When replacement is the better choice, we’ll tell you honestly. We never pressure you into unnecessary work.
Annual descaling and inspection prevent future breakdowns and extend system life.
Tankless MaintenanceIf repair isn’t viable, we install new tankless units with professional assessment and commissioning.
Tankless Water Heater InstallationRadiant heating systems need specialist care. We repair boilers alongside tankless water heaters.
Boiler RepairIf repair costs add up, flexible financing makes repairs more manageable.
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