Pentair 42002-0024S Stack Flue Sensor
Part # 42002-0024S — the replacement stack/flue temperature sensor designed for use in select Pentair and Sta-Rite pool/spa gas heaters. This sensor monitors flue-gas temperature to ensure safe and proper combustion performance.
Key Features
- Designed specifically for gas-fired pool and spa heaters requiring a stack/flue sensor.
- Detects excessive flue-gas temperature or blocked flue conditions and signals the control system accordingly.
- OEM part that assures compatibility and reliability with the original heater model’s control electronics.
- Compact threaded design for drop-in replacement of the original sensor in the flue pipe or exhaust stack.
- Essential for avoiding error codes related to flue sensor faults and maintaining heater safety compliance.
Typical Applications
This sensor is used when the heater displays stack/flue sensor fault codes (such as E05 or E06) or when the original sensor has failed, corroded, or is out of spec. It is commonly installed in Pentair and Sta-Rite gas heaters to restore safe operation and proper exhaust monitoring.
Installation & Compatibility Notes
Before installing, turn off electrical power and gas supply to the heater and allow it to cool. Remove the heater flue cover or access panel, locate the existing stack/flue sensor, disconnect wiring, and unthread the old sensor. Thread in the new 42002-0024S sensor snugly (do not overtighten), reconnect the wiring in the same orientation, restore power and gas, and restart the unit. Monitor the heater through a full start-up to verify normal operation and no fault codes are present.
Why Choose This Sensor?
Selecting the correct OEM sensor like the 42002-0024S provides confidence in fitment, performance and heater safety. Generic or mismatched sensors may result in improper readings, recurrence of fault codes, or reduced heater lifespan. For pool professionals and service techs, this part ensures the heater operates within its designed limits.
Maintenance Tips
- Inspect the sensor and its mounting area annually for corrosion, soot accumulation or thermal damage.
- Check wiring connections for secure fit, insulation damage, or discoloration—loose or damaged wires often cause fault codes.
- Ensure the flue/exhaust piping is clear of obstructions or corrosion—sensor faults may be caused by blocked or damaged exhaust flow.
- When replacing the sensor as part of heater service, consider logging the heater runtime and verifying the flue-gas temperature is within specifications post-service.
Hours Of Operation:
Monday - Friday: 7:00 am to 5:00 pm Phoenix Time
Saturday: 8:00 am to 2:00 pm
Sunday: Closed
- We do not ship on Saturday or Sunday.
- Orders totaling more than $300 will require signature confirmation upon delivery.
- We process and prepare orders for shipment within 1 business day. Please note that many other pool supply retailers require 3–5 days of handling time before shipping.
- Orders placed after 1:00 pm Phoenix Time may not be eligible for same-day shipment.
- Expedited shipping options are available at checkout.
Return Policy:
- Products that are received damaged will receive a refund in store credit.
- Most products are eligible for return within 30 days of receipt, except where noted below.
- To initiate a return, please complete an RMA form prior to sending your item back.
- Original shipping costs are non-refundable and will be deducted from the return credit.
- Items returned missing accessories or original packaging, or that are not in the same condition as received, may be subject to a restocking fee of up to 100% depending on the condition of the item upon return.
- Some returns will be charged an automatic 15% restocking fee.
- We are unable to issue refunds for items that have been damaged or rendered inoperable due to installer error.
- Please complete the return form to receive your RMA number and return shipping label.
- Chemical products are not eligible for return under any circumstances.
- The Pentair Colorsync 618031 is not eligible for return.
- Pool cleaners are not eligible for return.
- Opened seals and o-rings are not eligible for return.
- Capacitors are not eligible for return.
- Plastic popup tools are not eligible for return.
- Automation components and circuit boards are not eligible for return.
- If a light is returned due to a reported malfunction and is found to be fully operational upon testing, return shipping costs and a restocking fee will be deducted from the refund.
- Orders refused at the time of delivery will be subject to the original shipping costs being deducted from the refund.
