Same-day diagnostics and repair for every major brand
Tankless Water Heater Repair in Tupelo, MS Done Right
When your tankless water heater quits, you need tankless water heater repair Tupelo MS homeowners can count on. Our licensed techs diagnose Rheem, Navien, Rinnai, and Bradford White units the same day you call. We carry common parts on every truck, so most repairs finish in one visit. No hot water? Error code flashing? We'll get you back to endless hot showers fast.
Tankless water heater repair restores on-demand hot water by fixing the ignition, flow sensor, heat exchanger, or venting on a gas or electric tankless unit. Yearly descaling prevents most tankless repairs in Tupelo's moderately hard water.
Live phone supportUpfront optionsBacked workmanship
What's included
What Our Tankless Water Heater Repair Includes
Every repair call includes a full diagnostic, not just the fix. Here's what's covered in the standard service. Parts that fail outside normal wear, like a cracked heat exchanger, are quoted separately before we proceed.
Full Diagnostic and Error Code Scan
We test inlet and outlet temperatures, gas pressure, flow rate, and pull stored fault codes with a manufacturer reader. This 30- to 45-minute process tells us exactly what's wrong before we quote the repair.
Heat Exchanger Descaling
We flush the heat exchanger with a descaling solution and pump, removing mineral scale that restricts flow. This restores hot water output and is the single most common fix for Tupelo's hard water.
Inlet Filter Cleaning or Replacement
The inlet filter screen catches debris before it reaches the heat exchanger. We clean or replace it on every service call. A clogged screen is a $0 fix that prevents a $900 repair.
Igniter and Flame Rod Service
If your unit won't fire, the igniter or flame rod is usually the cause. We test both, clean the flame rod, and replace the igniter if needed. Parts are on the truck for Rheem, Navien, and Rinnai.
Gas Pressure and Venting Check
We verify gas pressure at the manifold and inspect venting for code compliance. A unit that runs but vents wrong is a safety risk. We correct it or tell you exactly what needs to change.
Post-Repair Testing and Walkthrough
We run a full heating cycle and measure outlet temperature at the fixture. You get a walkthrough of what failed and how to prevent it. The old part stays with you, and the repair carries a 1-year workmanship warranty.
Service overview
Tankless Water Heater Repair Tupelo MS: What It Actually Involves
Tankless water heater repair Tupelo MS is the diagnostic and mechanical work that restores an on-demand unit to full heating capacity. We test inlet and outlet water temperatures, inspect the heat exchanger for scale, check the flow sensor, and verify gas pressure at the manifold. We also clean or replace the igniter, flame rod, and inlet filter screen. Most units throw an error code before they fail completely, and that code tells us exactly where to start.
Tupelo's water runs moderately hard, and that mineral content is the number one killer of tankless units here. Scale builds on the heat exchanger, flow drops, and the unit starts short-cycling or shutting off mid-shower. Cold snaps make it worse: a brief freeze can crack a condensate line or trip a pressure switch. If you're searching for tankless water heater repair near me Tupelo MS after a cold morning with no hot water, that's usually what we find.
How we workWe verify the cause, compare realistic options, and confirm the repair before we leave.
The service timeline
Our Tankless Water Heater Repair Process
The process flexes to the condition, but these checkpoints keep decisions clear.
Phone Triage
You call (662) 550-8327 and describe what's happening. We ask for the brand, model, and any error code on the display. That five-minute conversation lets us load the right parts before we roll. If it's a simple reset, we'll walk you through it right then.
On-Site Diagnosis
A licensed tech arrives in a stocked truck and runs a full diagnostic: inlet and outlet temperatures, gas pressure, flow rate, and fault codes. This takes 30 to 45 minutes. You get a written flat-rate price before we touch a wrench.
Repair or Descaling
Most jobs are descaling, igniter replacement, or flow sensor cleaning. Those take one to two hours. If the heat exchanger is cracked or the PCB is dead, we quote the part and give you the repair-versus-replace math on the spot.
Testing and Calibration
After the repair, we run the unit through a full heating cycle and measure outlet temperature at the fixture. We verify it hits 120 degrees within 15 seconds of the tap opening. If it doesn't, we keep working until it does.
Walkthrough and Warranty
We show you what failed, what we replaced, and how to prevent it next time. You get a 1-year workmanship warranty on the repair. We also leave the old part so you can see exactly what came out of your unit.
Tools & methods
Tools and Methods We Use for Tankless Repair
Purpose-built equipment, used by trained technicians, so the job is done accurately the first time.
Combustion Analyzer
Measures carbon monoxide and oxygen levels in the exhaust to verify the unit is burning clean and venting safely. Required on every gas appliance service.
Digital Flow Meter
Measures gallons per minute at the outlet to confirm the unit is meeting its rated flow. Low flow points to scale or a clogged inlet filter.
Descaling Pump and Kit
Circulates a descaling solution through the heat exchanger to dissolve mineral scale. This is the core fix for Tupelo's hard water problems.
Manufacturer Fault Code Reader
Pulls stored error codes from Rheem, Navien, Rinnai, and Bradford White units. A generic scanner won't read these; ours does.
Pipe Wrench and Press Fitting Tool
Used to remove and replace gas and water connections. The press fitting tool lets us make code-compliant joints without an open flame in tight spaces.
Soldering Torch
For copper piping repairs where a soldered joint is the right call. We use it with proper heat shields to protect the unit's electronics.
Leak Detection Equipment
Electronic leak detectors and moisture meters to find hidden leaks around the unit and in the wall cavity before they cause mold or structural damage.
Use cases
When to Call for Tankless Water Heater Repair in Tupelo
These examples show how the service framework adapts rather than forcing every call through one repair.
Rheem Igniter Failure Fixed Same Day
A landlord in Downtown Tupelo called at 8 a.m. after a tenant reported no hot water. The Rheem unit was throwing an F7 code and wouldn't fire. The tenant had been without hot water for two days. → We diagnosed a failed igniter, replaced it with a part from the truck, and tested the unit through three full heating cycles. Outlet temp hit 120 degrees in 12 seconds. The tenant had hot water by 11 a.m. the same day.
Frozen Condensate Line Repaired After Cold Snap
After a January freeze, a homeowner in Mill Village woke up to a dead tankless unit and a puddle under it. The condensate line had frozen, cracked, and leaked water onto the unit's electronics. → We thawed and replaced the condensate line, dried the electronics, and tested the unit. It fired on the first try. We also adjusted the freeze protection settings and insulated the line. Total repair: $310.
Read the display
Common Tankless Error Codes and What They Mean
Tankless water heaters show a fault code on the display when a safety check fails. These 6 codes on Rinnai and Navien units cover most of the repair calls we run in Tupelo.
Rinnai Code 11: No Ignition
The burner did not light. Common causes are low gas pressure, a closed gas valve, a dirty igniter, or air in a new gas line.
Rinnai Code 12: Flame Failure
The flame lit and went out. A blocked vent, a dirty flame rod, or low gas supply under full load shuts the burner down.
Rinnai LC: Scale Buildup
The unit detected lime scale in the heat exchanger. A descaling flush clears the code and restores full heat transfer.
Navien E003: Ignition Failure
The Navien burner failed to ignite. We check gas pressure with a manometer, then the igniter and gas valve.
Navien E012: Flame Loss
The flame dropped out during operation. Vent blockage, condensate backup, or a weak gas supply are the usual causes.
Rinnai Code 10: Vent Blockage
The unit sensed a blocked air supply or exhaust. Bird nests, leaves, or a crushed vent pipe trip this code most often.
Prevent the next repair
Tankless Water Heater Maintenance in Tupelo
A tankless water heater needs 4 maintenance tasks each year to reach its 20-year service life in hard water.
Descale the Heat Exchanger
A pump circulates descaling solution through the isolation valves for 45 to 60 minutes and dissolves lime scale.
Clean the Inlet Filter
The cold-water inlet screen catches grit and scale flakes that restrict flow and trigger low-flow shutoffs.
Check Venting and Condensate
Bird nests, leaves, and a frozen condensate line cause flame failure codes after a cold snap.
Test Gas Pressure
A manometer reading under full fire confirms the gas line still feeds the burner at its rated BTU input.
Problems we solve
Tankless Water Heater Problems We Fix in Tupelo
Most tankless failures start small and get expensive if you ignore them. Here are the problems we see most in Tupelo and how we solve them.
No hot water or water that never gets hot enough
We test the flow sensor, inlet filter, and gas pressure to find the restriction. Most cases are scale buildup or a dirty filter. We descale the exchanger, clean the filter, and verify 120-degree output at the tap before we leave.
Error code flashing on the display
We pull the stored fault code with a brand-specific reader and trace it to the actual component. Whether it's an F7 on a Rheem or an 11 on a Navien, we've seen it. You get a real diagnosis and a flat-rate repair price.
Water leaking from the unit or its connections
We isolate the leak source, whether it's a supply line, a condensate drain, or an internal O-ring. We repair it with new fittings and plumber's tape, then dry and test the unit. If water reached the electronics, we inspect and test those too.
Unit runs but water temperature fluctuates
We descale the heat exchanger and test the mixing valve and flow sensor. If the valve is sticking, we replace it. Most fluctuation issues resolve with a descaling and a new inlet filter, both done in one visit.
Pricing process
Tankless Water Heater Repair Cost in Tupelo MS
$150 - $900 depending on the repair
Type of Failure
A descaling or filter cleaning is on the low end at $150 to $250. Igniter or flow sensor replacement runs $250 to $450. Heat exchanger or PCB replacement is the high end at $600 to $900. The diagnostic tells us which one you're facing.
Unit Brand and Model
Parts for Rheem and AO Smith are widely available and cost less. Navien and Rinnai parts can run higher, especially for newer condensing models. We stock the most common parts to keep your cost down.
Access to the Unit
A wall-hung unit in an open garage is a quick job. A unit crammed into a closet behind a water softener takes longer to access and service. We quote the labor based on what we see, not a flat hourly rate.
Customer reviews
What Tupelo Homeowners Say About Our Tankless Repair
★★★★★
“Our Navien stopped heating on a Sunday morning. Called TupelomsPlumbing and a tech was here by 2 p.m. He pulled an error code, found a clogged inlet filter, and cleaned it in 45 minutes. $150 total. We had hot water before dinner. He also showed me how to flush the unit myself next time.”
★★★★★
“We'd been dealing with lukewarm showers for months. Two other companies told us to replace the whole unit. TupelomsPlumbing descaled the heat exchanger and replaced the flow sensor. Outlet temp went from 98 to 122 degrees. Saved us $2,500 on a new unit. Honest folks.”
★★★★★
“I manage six rentals in Tupelo, four with tankless units. TupelomsPlumbing is who I call. They fixed a Rheem that was throwing an F7 code in one visit. Flat-rate pricing means no surprise bills, and they leave the old parts so I can see what failed. That's how you run a business.”
Questions before we arrive
Frequently Asked Questions About Tankless Water Heater Repair
Why is my tankless water heater not working in Tupelo MS?
The most common cause in Tupelo is mineral scale on the heat exchanger, which restricts flow and trips the unit's safety shutoff. Other frequent culprits are a dirty inlet filter screen, a failed igniter, or low gas pressure. If your display shows an error code, that code narrows it down fast. We diagnose all of these on-site in under an hour.
How much does tankless water heater repair cost in Tupelo?
Typical 2026 pricing in Tupelo runs $150 to $450 for common repairs like descaling, igniter replacement, or flow sensor cleaning. Heat exchanger or PCB replacement can run $600 to $900. The diagnostic fee is $89 and gets waived when you approve the repair. We give you the full price before any work starts.
Can you repair tankless water heater in Tupelo Mississippi?
Yes. We repair all major brands including Rheem, Navien, Rinnai, Bradford White, and AO Smith. Our techs hold Mississippi State Plumbing Licenses and carry parts for same-day fixes. We service Tupelo, Verona, Saltillo, and the rest of Lee County. Call (662) 550-8327 and we'll get you on the schedule.
Should I repair or replace my tankless water heater in Tupelo MS?
Repair if the unit is under 10 years old and the heat exchanger is intact. Replace if it's over 12 years old, the heat exchanger is cracked, or you've paid for three repairs in two years. We run the math with you on-site: repair cost versus a new unit with a 10-year warranty. No pressure either way.
How often should a tankless water heater be flushed in Tupelo?
A tankless water heater should be flushed once a year in Tupelo, and every 6 months in homes without a water softener and with heavy hot water use. The flush removes lime scale from the heat exchanger and clears LC scale codes.
Why does my tankless water heater go hot then cold?
A tankless water heater goes hot then cold from a "cold water sandwich", a low flow rate below the unit's activation point, or a dirty inlet filter. Most units need about 0.5 GPM (1.9 liters per minute) of flow to keep the burner lit, so a low-flow shower head can shut it off mid-shower.
Can a tankless water heater freeze in Tupelo?
Yes, a tankless water heater can freeze in Tupelo during a hard freeze, mostly on outdoor units and exposed condensate lines. Built-in freeze protection works only while the unit has power and gas. Keep power on during freezes, and drain the unit if the power goes out.
Related services
Other Services We Handle for Tupelo Homes
Emergency Plumbing
When your tankless unit leaks or fails at 2 a.m., our emergency line is open. We handle burst pipe, water heater failure, and frozen pipes across Tupelo. Same techs, same trucks, 24/7.
Residential Plumbing
Tankless repair is part of a bigger picture. We also fix leaky faucet, running toilet, and low water pressure issues in Tupelo homes. One call covers the whole house.
Commercial Plumbing
Restaurants and salons in Downtown Tupelo run tankless units hard. We service commercial tankless systems, including multiple-unit manifolds, with minimal downtime for your business.Ready when you are
Get Tankless Water Heater Repair Tupelo MS Today
No hot water is an emergency, and we treat it like one. Call (662) 550-8327 and a licensed tech will diagnose your unit today. Flat-rate pricing, parts on the truck, 1-year workmanship warranty. We serve all of Tupelo and Lee County.
Talk with the local team
Request Tankless Water Heater Repair
Call (662) 550-8327 to reach a live dispatcher. We answer 24/7 for emergencies and book same-day appointments Monday through Friday. If you prefer email, send your address and a description of the problem to info@tupelomsplumbing.com and we will reply with an arrival window.