Should Tankless Water Heaters Be Serviced?

If you own a tankless water heater in Modesto, the short answer is yes — service matters. These on-demand systems run cleaner and more efficiently than traditional tanks, but they still collect scale, need air intake checks, and benefit from software updates and combustion tuning. We see it every week across Modesto, Riverbank, Salida, Ripon, and Ceres: a well-maintained tankless unit runs quieter, delivers steadier hot water, and uses less energy. Skip service, and performance slips. Response time lengthens. Error codes pop up at the worst moments.

At Knights Plumbing and Drain, we install, service, and repair tankless systems from Navien, Noritz, Rinnai, Takagi, and Rheem. We’ll share what maintenance really means, how often you should schedule it in Stanislaus County, and what warning signs to watch for. If you are searching for tankless water heater services near me and you live in the Modesto area, consider this your local guide.

What “service” means for a tankless unit

Servicing a tankless water heater is different from flushing a traditional tank. There’s no big reservoir to drain, and the risks shift from corrosion to mineral scale and combustion quality. On a typical visit, our techs:

• Descale the heat exchanger with a safe, food-grade solution to remove calcium and magnesium buildup.
• Clean the inlet water filter and cold-water flush ports, then verify flow on a calibrated meter.

Beyond those steps, we check venting for clearance and slope, inspect the condensate trap on condensing models, and verify gas pressure under load. These steps protect the heart of the system: the heat exchanger and burner assembly.

How often does Modesto water require maintenance?

Modesto’s municipal water usually tests in the hard to very hard range. In practical terms, homeowners see scale buildup on faucet aerators within months. Tankless units concentrate that effect because they exchange heat through narrow passages. Without service, scale acts like an insulator. The burner fires harder to deliver the same outlet temperature, which raises fuel use and stresses components.

• Homes with no softening: plan on annual descaling and inspection.
• Homes with a properly sized and maintained softener: every 18 to 24 months is reasonable.
• Well water or agricultural tie-ins with high TDS: we recommend water testing and a custom interval, often twice per year until baseline is clear.

If your family uses lots of hot water — long showers, back-to-back laundry, a big soaking tub — shorten the interval. We judge frequency by what we see inside your system the first time we service it, then set reminders that match your water and usage.

Real-world signs your tankless needs service

You do not have to wait for a failure. Subtle changes usually show up first. Households in the Modesto grid often call us for:

• Delayed hot water at distant fixtures that used to heat faster.
• Temperature “hunting” where water surges warmer and cooler during a shower.
• Error codes such as 10, 11, 12, 29, or 61 on common brands, tied to ignition, airflow, or heat exchanger protection.
• A new, high-pitched whine or whooshing sound while the unit runs.
• Increasing energy bills with no change in habits.

If you tap the hot side and feel a blast of heat followed by lukewarm water, that points to scale. If you hear the unit clicking repeatedly, failing to ignite, that points to gas supply, igniter wear, or fouled flame sensor. We handle both during a standard service call.

What we do during a Knights tankless tune-up

We approach each service with a checklist and the judgment that comes from field work in older Modesto bungalows, new-builds off Pelandale, and ranch homes on the edge of town. On most jobs we:

• Verify inlet gas pressure static and under demand using a manometer, and compare to the manufacturer’s spec.
• Check combustion air and venting path for restrictions, nesting, or improper slopes.
• Pull, inspect, and clean the flame rod and spark igniter. Replace if the ceramic is cracked or pitted.
• Test the fan motor and air proving switch. Clean the blower wheel if dust or lint is present.
• Remove and rinse the inlet water screen and any pre-filters.
• Descend into the heat exchanger with a recirculating pump and solution until pH returns near neutral on discharge, typically 30 to 60 minutes depending on scale.
• Bleed air pockets, then confirm delta-T across the exchanger and target outlet temperature under flow.
• For condensing units, flush the condensate trap, check neutralizer media, and verify drain fall.
• Update firmware if supported and available, then run a fixture test at your kitchen sink and master shower to make sure the experience matches the gauges.

This is not a quick drain-and-go. It is a performance visit. You should feel the difference immediately — faster hot water delivery and steadier temperature at the tap.

Does service really save money?

We track data from repeat clients. After a heavy descale on a scaled Modesto unit, we often see gas usage drop 10 to 20 percent, measured on similar weather and family use. The burner modulates lower once the exchanger is clean, and cycles last shorter. More important than utility costs, you postpone costly parts replacements. A burnt heat exchanger can cost half the price of a new unit. Many are avoidable with annual descaling and proper combustion checks.

From the warranty angle, several manufacturers expect documented maintenance to keep coverage valid, especially in hard-water zip codes. If we install and service your unit, we keep digital records and photos to back your warranty.

Tankless vs. tank: why maintenance differs

A tank heater fights corrosion and sediment. A tankless system fights scale and airflow problems. Both need care, but the failure modes differ. Tank heaters slowly lose capacity and then spring leaks. Tankless systems tend to throw protective codes long before a major failure, which is good news if you respond. Waiting until the unit locks out often turns a 90-minute service into a lengthy repair with parts. We built our routes to allow same-day diagnostics across Modesto, but proactive service keeps you off the emergency schedule.

Edge cases we see in Modesto homes

Real houses bring quirks. Here are patterns we run into and how we handle them.

Small gas meters on multi-appliance homes: A tankless unit can pull 150 to 199k BTU by itself. Add a range, furnace, and dryer, and the meter can starve the system during winter. Symptoms include ignition failures and error codes during simultaneous use. We provide meter sizing notes and coordinate with PG&E to upgrade if needed.

Improper vent terminations: We often find vent caps too close to eaves, fences, or windows around North Modesto and Vintage Faire. That can recirculate exhaust. We measure clearances, check for staining, and rework terminations to code.

Scale from well tie-ins: Out on the edges of Salida and Ripon, wells can drive scale fast. We install isolation valves if missing, add filter and softening where appropriate, and shorten service intervals temporarily to stabilize performance.

Retrofits with long pipe runs: Older homes near Graceada Park often have long copper runs. A tankless unit saves energy but cannot speed water in the pipe. We discuss recirculation options — dedicated lines where possible, crossover valves when walls are closed — and set timers or demand-pump controls to reduce wait time without burning gas all day.

DIY vs. professional service

A handy homeowner can flush a tankless unit if isolation valves are present and instructions are followed. Pumps and hoses are easy to rent, and food-grade descaler is available. The limits show up around gas and combustion. Many issues we fix were missed by well-intended DIY work: poor vent slope, fouled flame sensors, fan imbalance, and gas pressure that reads fine at idle but fails under load. Those checks require the right tools.

If you prefer to handle intermediate tasks, we’re happy to split the work. You can descale between visits, and we perform the combustion analysis, vent inspection, and electronics check annually. We care about results, not gatekeeping.

How long does a service appointment take?

Most maintenance visits take 60 to 90 minutes. Heavily scaled exchangers can stretch to two hours. If parts are failing — igniter, flame rod, fan motor — we stock common replacements on our trucks, so most repairs add 30 to 60 minutes. We schedule with clear arrival windows in Modesto, Ceres, Riverbank, and Salida, and we call ahead when we are on the way. You should not lose a full day to a simple service.

What service costs in our area

Prices vary by model, access, and severity of scale, but here is a realistic range in Modesto:

• Annual tankless service with descale and inspection usually falls between $189 and $289.
• Condensing models that need condensate neutralizer media add a modest charge for materials.
• Parts like igniters and flame sensors typically run $80 to $180 installed.
• Complex issues such as blocked venting or gas supply upgrades are quoted after diagnostics.

We give upfront pricing before work starts. If we find something unusual, we show you the readings and the part before we proceed.

How to choose a tech for “tankless water heater services near me”

If you are comparing companies in Modesto or nearby neighborhoods, look for a team that handles both installation and service. Experience across brands matters because error codes vary and parts placement differs. Ask a few direct questions:

• Will you perform a combustion or gas pressure check under load, not just a flush?
• Do you have isolation valves and flush ports if my unit lacks them?
• Do you stock common tankless parts on your truck?
• Do you record baseline readings so future visits can compare?
• Will you verify venting and condensate components?

If a provider focuses only on flushing, you are not getting full care. Tankless performance ties to air, gas, water quality, and software. A complete service covers all four.

What you can do between service visits

You can stretch the time between professional visits with a few simple habits. Keep laundry and cleaning chemicals away from the intake of indoor models, since vapors can corrode sensors and exchangers. Replace or clean pre-filters if your model uses them. If you have a water softener, keep salt topped off and the brine tank clean. Once a quarter, glance at the vent termination and make sure plants or storage have not blocked it. These small checks prevent nuisance calls.

Signs you may need repair, not just maintenance

Service will not fix every problem. If your unit trips the breaker, leaks from the heat exchanger case, or shows a cracked burner plate, that is repair territory. Repeated ignition failure after a full tune-up points to deeper issues such as a failing gas valve, damaged control board, or severe vent obstruction. At that point we will show you the costs and talk through repair versus replacement. In Modesto, many well-maintained units last 12 to 18 years. If yours is near that range and needs several major parts, replacement may pencil out better, especially if you want higher efficiency and faster recirculation.

Why local matters in Modesto

Local codes shape how tankless units vent and drain. Our inspectors care about clearances, seismic strapping for accessory components, and condensate handling on condensing models. Cold snaps in the Central Valley are short but sharp, so outdoor units need freeze protection and power backup plans. Hard water is a fact Modesto tankless water heater plumbers of life. All of that makes generic advice risky. We set service plans that match Modesto’s water and weather, and we keep parts on hand for the brands common in our area.

What homeowners say after a proper service

We hear the same comments after tune-ups in College Area, Sherwood Forest, and the Airport District. Showers hold a steady temperature. The unit sounds calmer. Hot water reaches the kitchen sink faster, especially with a recirculation setup. Gas bills dip a bit. And best of all, the beeping and fault codes stop. That is the point of maintenance: quiet, steady performance that fades into the background.

Ready to schedule?

If you searched for tankless water heater services near me and you live in Modesto, Knights Plumbing and Drain is nearby and ready. We offer same-day appointments when possible, honest pricing, and field-tested advice. Call, text, or book online. Tell us your brand and model if you know it, and share any error codes or symptoms. We will bring the right parts and tools to fix it in one visit.

Quick homeowner checklist before we arrive

• Clear a three-foot space around the unit so we can access panels and valves.
• If the unit is outdoors, secure pets and remove yard items blocking the vent.
• Note any error codes, noises, or recent changes in water temperature.
• Tell us about any water treatment equipment in the home.
• Share your typical hot water usage patterns, so we can test under similar load.

We’ll handle the rest. With regular service, your tankless water heater should deliver reliable hot water for years. If you want an expert to set the schedule and keep records, we can do that too. It takes one call, and you get a system that runs right, season after season, across Modesto and the neighboring communities.