State PR640CCVIT water heater Parts

On a State PR640CCVIT gas water heater, a bad thermocouple (or flame-sensing circuit, depending on your ignition style) shows up as a pilot that lights only while you hold the control down, then goes out when you release it. The gas valve closes because it is not receiving a strong “flame proven” signal.

• Pilot will not stay lit after you release the knob/button
• You have to relight the pilot frequently
• Burner shuts off early and water turns lukewarm
• Pilot flame is weak, yellow, or does not fully heat the sensor tip
• Pilot stays lit but the main burner will not stay on consistently

• Pilot flame quality: It should be steady and mostly blue, aimed directly at the thermocouple tip.
• Dirty pilot/burner: Lint and dust reduce flame heat and mimic a failed thermocouple.
• Thermocouple connection: Tighten the thermocouple nut at the gas control valve (snug, not over-tight).
• Combustion air and venting: Downdrafts or restricted air can blow out or cool the pilot.
• Gas supply: Confirm the shutoff valve is fully open and other gas appliances run normally.

A healthy thermocouple typically produces about 20 to 30 mV when heated; under load it is commonly 10 to 15 mV or higher.

The listed ignitor,pg 100109355 is an ignitor component, not a thermocouple. If you need a thermocouple, match it by your exact PR640CCVIT parts diagram and the part description used for “thermocouple” or “pilot assembly.”

The thermocouple or flame-sensing system is a safety device; it shuts the gas valve if a stable flame is not detected, preventing unburned gas from flowing.

Last updated: February 2026

For a State PR640CCVIT gas water heater, it’s cheaper to repair when the problem is a single, replaceable component and the tank is sound; it’s cheaper long-term to replace when the tank is leaking, the heater is 10+ years old, or repairs are becoming frequent and expensive.

• Replace now if you see water leaking from the tank body (not a fitting or valve).
• Repair if the issue is ignition or control related and the tank is not leaking.
• Replace if you’ve had multiple service calls in the last 12 to 24 months.
• Repair if the fix is a single part and labor is straightforward.
• Replace if corrosion, heavy sediment, or rusty water keeps returning after maintenance.

Use this simple comparison to decide fast.

These symptoms often point to a part-level repair rather than full replacement:

• No ignition or intermittent ignition
• Burner won’t stay lit
• Error code or status light indicates an ignition/control fault

Model-matched parts we commonly see involved:

• Ignitor,pg 100109355
• Switch 100111732

For code-based troubleshooting, use State gas water heater error codes.

A water heater replacement is a full system expense (unit, installation, venting checks, gas and water connections). When the tank is healthy, a targeted repair can restore safe hot water quickly; when the tank is failing, replacement prevents repeat downtime and water damage.

Last updated: February 2026

Common problems we see on State Select style gas water heaters (including the State PR640CCVIT) are ignition failures, inconsistent water temperature, nuisance shutdowns, and leaks or rumbling from sediment. Most fixes start with checking the ignition system, safety switches, and basic maintenance items.

• No hot water or burner will not light: ignitor/flame-sensing issue, gas supply issue, or a tripped safety device
• Pilot will not stay lit (or repeated ignition attempts): dirty burner area, weak ignition, or a failing ignition component
• Water temperature swings: temperature control problem, restricted airflow/venting, or scale/sediment affecting heat transfer
• Error code or blinking status light: a specific safety or ignition fault (use the model’s code chart)
• Rumbling, popping, or banging: sediment buildup in the tank
• Water around the heater: leaking fittings, drain valve, T and P relief valve discharge, or tank leak

If your symptoms match, these model-listed parts are good starting points for diagnosis and replacement:

• Confirm the gas shutoff valve is fully open and other gas appliances work.
• Verify the thermostat setting is reasonable (many homes run best around 120°F).
• Look for blocked air intake, lint, or dust around the burner area.
• If you have a status light, read the blink pattern and match it to State gas water heater error codes.
• If you hear rumbling, plan a tank flush to reduce sediment.

Ignition and safety-related problems can stop hot water completely, while sediment and corrosion issues reduce efficiency and shorten tank life. Catching the cause early helps avoid repeat shutdowns and prevents secondary damage to components.

Last updated: February 2026

State water heaters (including model PR640CCVIT) are made by A. O. Smith; the State brand is part of the A. O. Smith family of water-heating products.

Use the rating plate on the tank (usually on the side) to match the brand and model details before ordering parts or troubleshooting.

• Look for State as the brand name and PR640CCVIT as the model number
• Record the serial number (helps identify production details)
• Note fuel type: gas water heater
• If you see ignition or sensor-related faults, capture any status light pattern or code

Knowing the maker helps you choose compatible components (ignitor, switch, anode rod) and follow the right diagnostic flow for your gas control system.

• Use the model number PR640CCVIT when searching parts to avoid mismatches
• If you’re troubleshooting ignition problems, start with the State gas water heater error codes
• For common wear items, inspect the anode rod periodically; if yours matches the listed part, see 2-way 100109624

State and A. O. Smith products often share design platforms; using the correct brand family guidance reduces repeat failures and helps you order the right gas ignition and safety-control parts the first time.

Last updated: February 2026

A typical 50-gallon gas water heater costs about $600 to $1,500 for the unit, and about $1,000 to $3,000+ installed once labor, permits, and venting changes are included. For a State water heater like model PR640CCVIT, the final price depends most on venting type, efficiency, and local install requirements.

• Venting type: atmospheric vent vs. power vent vs. direct vent
• Efficiency level: standard vs. higher-efficiency designs
• Warranty length: common options are 6-year, 9-year, or 12-year coverage
• Gas and plumbing updates: shutoff valve, sediment trap, flex connector, piping changes
• Code and permit needs: seismic strapping, expansion tank, drip pan, discharge piping
• Labor rates: vary widely by region and job complexity

• Identify your current venting (metal flue up the chimney vs. fan-assisted vent)
• Check if the replacement is a like-for-like swap (same venting and footprint)
• Ask whether the quote includes permits, haul-away, and code upgrades
• Confirm if a new expansion tank, drip pan, or shutoff valve is required
• Compare warranty length and efficiency, not just tank size

A 50-gallon gas water heater price swings most when the job is not a simple swap. Venting changes and code upgrades often cost more than the difference between two tank models.

For troubleshooting costs tied to ignition or lockout issues (which can influence repair vs. replace decisions), use our State gas water heater error codes reference.

Last updated: February 2026

On the State PR640CCVIT gas water heater, many service parts are replaceable, including ignition and safety controls, tank protection parts, and common plumbing valves. Replacing the right part can restore reliable hot water, improve efficiency, and help prevent leaks or nuisance shutdowns.

• Ignition parts (ignitor, flame sensor style components, wiring as applicable)
• Safety and control parts (switches, control components, limit devices)
• Tank protection parts (anode rod)
• Plumbing service parts (drain valve, temperature and pressure relief valve)
• Burner and pilot components (pilot assembly, thermocouple, burner parts, depending on design)
• Gas control valve and related fittings (model dependent)

These are examples of parts we commonly see replaced on this model:

• Ignitor,pg 100109355
• Switch 100111732
• 2-way 100109624 (anode rod)

Water heaters combine gas, flame, and pressurized hot water. Using the correct replacement part for the PR640CCVIT helps keep ignition reliable and safety controls working as designed, and replacing wear items like the anode rod helps extend tank life.

If your heater is flashing an error or acting like it is in lockout, use State gas water heater error codes to narrow the failure to ignition, venting, or safety circuits before ordering parts.

Last updated: February 2026

Most gas water heaters, including the State PR640CCVIT, last 8 to 12 years. With consistent maintenance (flushing sediment, checking venting, and keeping the burner area clean), it’s common to reach 12 to 15 years before major components start failing.

• Water quality: hard water speeds up tank corrosion and sediment buildup
• Maintenance: annual flushing and periodic inspections extend tank life
• Temperature setting: higher setpoints increase stress on the tank and parts
• Usage level: heavy daily demand shortens life compared to light use
• Installation quality: correct venting and gas supply help prevent overheating and ignition issues

• Rust-colored water or metallic smell at hot taps
• Rumbling or popping sounds from heavy sediment
• Pilot or ignition problems that keep returning
• Water around the base of the tank (possible tank leak)
• Hot water runs out faster than it used to

A failing tank can waste gas, deliver inconsistent hot water, and eventually leak. Catching wear early helps you plan repairs or replacement before you lose hot water unexpectedly.

For troubleshooting ignition or status lights on State units, use our State gas water heater error codes guide.

Last updated: February 2026

Gas water heaters are being phased out in some areas because local air-quality and climate policies target emissions from burning natural gas, especially nitrogen oxides (NOx) that contribute to smog. For a State PR640CCVIT gas water heater, the practical impact is that replacement options and installation rules can vary by city and utility.

Most phase-outs are policy decisions aimed at reducing pollution from combustion appliances.

• Smog reduction: Gas burners can produce NOx, a key smog-forming pollutant.
• Climate goals: Some jurisdictions want fewer on-site fossil-fuel appliances over time.
• Building electrification: New construction is often the first target (then replacements later).
• Regional differences: Rules can be city-, county-, or air-district-specific.
• Incentives: Rebates sometimes encourage heat pump water heaters or other alternatives.

You can usually keep using a working gas water heater; the biggest changes tend to show up when you replace the unit or pull permits.

• Check your local permit requirements for water heater replacement.
• If your heater is acting up, look up the diagnostic light or code using State gas water heater error codes.
• If ignition is the issue, confirm wiring and burner area condition before replacing parts like ignitor,pg 100109355.
• If you have nuisance shutdowns, inspect safety circuits and connections before replacing a control part like switch 100111732.
• If you are maintaining tank life, plan periodic inspection of the anode rod such as 2-way 100109624.

Phase-outs can change what is legal to install, what qualifies for rebates, and what parts and service paths make the most sense. Knowing your local rules helps you avoid buying a gas replacement that cannot be permitted, and it helps you decide whether a repair is the better short-term move.

Last updated: February 2026