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Pentair MasterTemp® Digital IID Heavy Duty ASME Natural Gas Low NOx Heater 250K BTU

by Pentair
$5,852.01

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✓ Authorized Dealer
✓ Free Shipping
✓ Manufacturer Warranty
✓ Expert Support

The Pentair MasterTemp® Digital IID Heavy Duty ASME Natural Gas Low NOx Heater 250K BTU combines the MasterTemp platform's proven efficiency and reliability with both ASME certification and heavy-duty cupro nickel tubing — the complete commercial-grade specification at 250K BTU. User-friendly indicator lights make operation and monitoring a snap, and the compact, super-quiet design won't intrude on poolside leisure.

Built by Pentair with ASME-certified construction, HD cupro nickel tubing rated for low pH, high flow, and heavy use, Digital IID ignition, Low NOx emissions, and 250,000 BTU natural gas output. Backed by a 2-year warranty.

⚠️ Professional Installation Required. Pool heater installation involves gas line connections and electrical wiring. Always use a licensed contractor to ensure safety, code compliance, and warranty validity.

Key Features

ASME Certified Construction

Required for many commercial pool installations — meets the most rigorous pressure vessel standards.

Cupro Nickel Tubing (HD)

Withstands low pH, high flow, and heavy use — the full HD specification.

250,000 BTU Natural Gas

Mid-range capacity in the ASME HD MasterTemp platform.

Digital IID Ignition

Intermittent Ignition Device — reliable electronic ignition without a standing pilot light.

Low NOx Certified

Meets low emissions standards — green certified.

Digital Indicator Lights

User-friendly indicator lights for simple operation and monitoring.

Compact, Quiet Design

Same 23-inch wide MasterTemp cabinet — super-quiet operation.

Indoor and Outdoor Rated

Suitable for both indoor and outdoor pool and spa installations.

2-Year Warranty

Pentair warranty coverage.

Who It's For

  • Commercial pool installations requiring both ASME certification and HD cupro nickel tubing at 250K BTU
  • Low pH, high flow, or heavy use applications where standard tubing isn't sufficient
  • Salt water commercial pools at 250K BTU needing maximum material durability
  • Anyone who needs the full commercial-grade MasterTemp spec — ASME + HD — at 250K BTU

Specifications

Heating Performance

BTU Input / Output 250,000 BTU
Fuel Type Natural Gas
Ignition Digital IID (Intermittent Ignition Device)
Emissions Low NOx
Max Flow Rate 120 GPM

Construction

Tubing Material Cupro Nickel (HD)
Control Type Digital (Indicator Lights)

Installation

Gas Connection 0.75 in
Voltage 120V / 240V
Frequency 60 Hz
Phase Single
Application Indoor / Outdoor / Pool / Spa

Physical

Product Weight 144 lb
Cabinet Dimensions 23 W × 28.2 D × 21 H in
Shipping Dimensions 36 × 25 × 30 in

Approvals & Warranty

Certifications ASME Certified
Energy Efficient Yes (Green Certified)
Warranty 2 Years

What's in the Box

  • Pentair MasterTemp Digital IID HD ASME 250K Natural Gas Heater
  • Union Fittings
  • User Manual

Warranty

The MasterTemp Digital IID HD ASME 250K comes with a 2-year manufacturer warranty from Pentair. Clearflow Pool Supply is an authorized Pentair dealer and will assist with any warranty service needed.

Downloads

Frequently Asked Questions

How does this (461020) compare to the other 250K ASME model (460771)?

Both are ASME-certified 250K BTU MasterTemp natural gas heaters. The 461020 adds heavy-duty cupro nickel tubing — making it the full commercial spec for low pH, high flow, or heavy use applications. The 460771 uses standard heat exchanger materials and is suitable when ASME certification is required by code but HD tubing isn't needed for the water chemistry or application.

What does ASME certified mean for this heater?

ASME (American Society of Mechanical Engineers) certification means the heat exchanger was built to the most rigorous pressure vessel standards. Many commercial pool installations — hotels, fitness centers, aquatic facilities — require ASME-certified heaters per local code.

Does this heater require professional installation?

Yes. Gas heater installation involves connecting to a natural gas supply line, electrical wiring, and proper venting. A licensed contractor must perform the installation to ensure safety, local code compliance, and warranty validity.

Can it be used indoors?

Yes. The MasterTemp is rated for both indoor and outdoor installation. Indoor installations require proper venting per local code. Consult the operating manual and a licensed contractor for indoor venting requirements.

Description
✓ Authorized Dealer ✓ Free Shipping ✓ Manufacturer Warranty ✓ Expert Support

The Pentair MasterTemp® Digital IID Heavy Duty ASME Natural Gas Low NOx Heater 250K BTU combines the MasterTemp platform's proven efficiency and reliability with both ASME certification and heavy-duty cupro nickel tubing — the complete commercial-grade specification at 250K BTU. User-friendly indicator lights make operation and monitoring a snap, and the compact, super-quiet design won't intrude on poolside leisure.

Built by Pentair with ASME-certified construction, HD cupro nickel tubing rated for low pH, high flow, and heavy use, Digital IID ignition, Low NOx emissions, and 250,000 BTU natural gas output. Backed by a 2-year warranty.

⚠️ Professional Installation Required. Pool heater installation involves gas line connections and electrical wiring. Always use a licensed contractor to ensure safety, code compliance, and warranty validity.

Key Features

ASME Certified Construction

Required for many commercial pool installations — meets the most rigorous pressure vessel standards.

Cupro Nickel Tubing (HD)

Withstands low pH, high flow, and heavy use — the full HD specification.

250,000 BTU Natural Gas

Mid-range capacity in the ASME HD MasterTemp platform.

Digital IID Ignition

Intermittent Ignition Device — reliable electronic ignition without a standing pilot light.

Low NOx Certified

Meets low emissions standards — green certified.

Digital Indicator Lights

User-friendly indicator lights for simple operation and monitoring.

Compact, Quiet Design

Same 23-inch wide MasterTemp cabinet — super-quiet operation.

Indoor and Outdoor Rated

Suitable for both indoor and outdoor pool and spa installations.

2-Year Warranty

Pentair warranty coverage.

Who It's For

  • Commercial pool installations requiring both ASME certification and HD cupro nickel tubing at 250K BTU
  • Low pH, high flow, or heavy use applications where standard tubing isn't sufficient
  • Salt water commercial pools at 250K BTU needing maximum material durability
  • Anyone who needs the full commercial-grade MasterTemp spec — ASME + HD — at 250K BTU

Specifications

Heating Performance

BTU Input / Output 250,000 BTU
Fuel Type Natural Gas
Ignition Digital IID (Intermittent Ignition Device)
Emissions Low NOx
Max Flow Rate 120 GPM

Construction

Tubing Material Cupro Nickel (HD)
Control Type Digital (Indicator Lights)

Installation

Gas Connection 0.75 in
Voltage 120V / 240V
Frequency 60 Hz
Phase Single
Application Indoor / Outdoor / Pool / Spa

Physical

Product Weight 144 lb
Cabinet Dimensions 23 W × 28.2 D × 21 H in
Shipping Dimensions 36 × 25 × 30 in

Approvals & Warranty

Certifications ASME Certified
Energy Efficient Yes (Green Certified)
Warranty 2 Years

What's in the Box

  • Pentair MasterTemp Digital IID HD ASME 250K Natural Gas Heater
  • Union Fittings
  • User Manual

Warranty

The MasterTemp Digital IID HD ASME 250K comes with a 2-year manufacturer warranty from Pentair. Clearflow Pool Supply is an authorized Pentair dealer and will assist with any warranty service needed.

Downloads

Frequently Asked Questions

How does this (461020) compare to the other 250K ASME model (460771)?

Both are ASME-certified 250K BTU MasterTemp natural gas heaters. The 461020 adds heavy-duty cupro nickel tubing — making it the full commercial spec for low pH, high flow, or heavy use applications. The 460771 uses standard heat exchanger materials and is suitable when ASME certification is required by code but HD tubing isn't needed for the water chemistry or application.

What does ASME certified mean for this heater?

ASME (American Society of Mechanical Engineers) certification means the heat exchanger was built to the most rigorous pressure vessel standards. Many commercial pool installations — hotels, fitness centers, aquatic facilities — require ASME-certified heaters per local code.

Does this heater require professional installation?

Yes. Gas heater installation involves connecting to a natural gas supply line, electrical wiring, and proper venting. A licensed contractor must perform the installation to ensure safety, local code compliance, and warranty validity.

Can it be used indoors?

Yes. The MasterTemp is rated for both indoor and outdoor installation. Indoor installations require proper venting per local code. Consult the operating manual and a licensed contractor for indoor venting requirements.

Shipping

Shipping Policy

At ClearFlow Pool Supply, we keep things simple.

👉 Free shipping on all orders within the United States.
No hidden fees. No surprises.


Order Confirmation

As soon as you place your order, you’ll receive an order confirmation email.

This means:

  • we’ve received your order
  • your payment method has been pre-authorized

Once your order is in our system, we verify:

  • product availability
  • inventory status with our suppliers

If an item is unavailable or backordered, we will:

  • void the pre-authorization
  • contact you promptly to discuss alternatives

If your item is in stock and ready to ship (typically within 3–5 business days), your order will be processed and prepared for shipment.


Order Shipment

Orders that are in stock will typically ship within 3 business days.

You will receive a shipping confirmation email with tracking details within 24 hours of your order leaving the warehouse.

If you do not receive tracking information within 4 business days, please contact us at:

👉 support@clearflowpoolsupply.com 


Shipping Scope

We currently ship to customers within the United States.

Due to the size and nature of many pool equipment products, some orders may ship via freight carriers. Delivery times may vary depending on location and product availability.


International Orders

At this time, our products are designed and configured for the U.S. market, operating on 110V electrical systems and meeting U.S. safety standards.

We may be able to accommodate international orders on a case-by-case basis.
If you are located outside the United States, please contact us to request a custom shipping quote.


Damaged Shipments

Please inspect your order upon delivery.

If you notice any damage:

  • note it with the carrier before signing
  • or refuse the delivery if damage is severe

If you accept the delivery:

👉 Take clear photos of:

  • the packaging
  • the damaged product

Then email us immediately at:

👉 support@clearflowpoolsupply.com

We will work with you quickly to resolve the issue.


Returns

For full details on returns, please visit our Returns Policy page.

Why Buy from Us

Why Buy From Us

We understand—you have options when it comes to buying pool equipment online.

At ClearFlow Pool Supply, our goal is simple:

👉 provide reliable products
👉 offer a straightforward buying experience
👉 and support you every step of the way

Here’s what sets us apart.


Free Shipping Across the U.S.

No hidden fees. No surprises.

All orders ship free within the United States, including large and heavy equipment.


Competitive Pricing

We work to offer strong, competitive pricing across our entire catalog.

If you find the same product available online at a lower total price, feel free to reach out—we’re happy to review it.


30-Day Return Policy

If your product isn’t the right fit, we offer a 30-day return window.

We aim to make the process as simple and straightforward as possible.
(See our Returns Policy for full details.)


Reliable Equipment

We focus on products that matter:

  • durable
  • proven
  • built for long-term use

Our goal is to help you avoid the frustration of unreliable or low-quality equipment.


Customer-Focused Support

We’re here to help before and after your purchase.

Whether you’re:

  • replacing a component
  • upgrading your system
  • or choosing equipment for the first time

👉 we’re here to make the process easier


Our Commitment

We stand behind what we sell.

If something isn’t right, we’ll work with you to resolve it quickly and fairly.


Price Match Policy

If you find the same product offered at a lower total price (including shipping), contact us at:

👉 support@clearflowpoolsupply.com

We’ll review the offer and do our best to match it.

Description
✓ Authorized Dealer ✓ Free Shipping ✓ Manufacturer Warranty ✓ Expert Support

The Pentair MasterTemp® Digital IID Heavy Duty ASME Natural Gas Low NOx Heater 250K BTU combines the MasterTemp platform's proven efficiency and reliability with both ASME certification and heavy-duty cupro nickel tubing — the complete commercial-grade specification at 250K BTU. User-friendly indicator lights make operation and monitoring a snap, and the compact, super-quiet design won't intrude on poolside leisure.

Built by Pentair with ASME-certified construction, HD cupro nickel tubing rated for low pH, high flow, and heavy use, Digital IID ignition, Low NOx emissions, and 250,000 BTU natural gas output. Backed by a 2-year warranty.

⚠️ Professional Installation Required. Pool heater installation involves gas line connections and electrical wiring. Always use a licensed contractor to ensure safety, code compliance, and warranty validity.

Key Features

ASME Certified Construction

Required for many commercial pool installations — meets the most rigorous pressure vessel standards.

Cupro Nickel Tubing (HD)

Withstands low pH, high flow, and heavy use — the full HD specification.

250,000 BTU Natural Gas

Mid-range capacity in the ASME HD MasterTemp platform.

Digital IID Ignition

Intermittent Ignition Device — reliable electronic ignition without a standing pilot light.

Low NOx Certified

Meets low emissions standards — green certified.

Digital Indicator Lights

User-friendly indicator lights for simple operation and monitoring.

Compact, Quiet Design

Same 23-inch wide MasterTemp cabinet — super-quiet operation.

Indoor and Outdoor Rated

Suitable for both indoor and outdoor pool and spa installations.

2-Year Warranty

Pentair warranty coverage.

Who It's For

  • Commercial pool installations requiring both ASME certification and HD cupro nickel tubing at 250K BTU
  • Low pH, high flow, or heavy use applications where standard tubing isn't sufficient
  • Salt water commercial pools at 250K BTU needing maximum material durability
  • Anyone who needs the full commercial-grade MasterTemp spec — ASME + HD — at 250K BTU

Specifications

Heating Performance

BTU Input / Output 250,000 BTU
Fuel Type Natural Gas
Ignition Digital IID (Intermittent Ignition Device)
Emissions Low NOx
Max Flow Rate 120 GPM

Construction

Tubing Material Cupro Nickel (HD)
Control Type Digital (Indicator Lights)

Installation

Gas Connection 0.75 in
Voltage 120V / 240V
Frequency 60 Hz
Phase Single
Application Indoor / Outdoor / Pool / Spa

Physical

Product Weight 144 lb
Cabinet Dimensions 23 W × 28.2 D × 21 H in
Shipping Dimensions 36 × 25 × 30 in

Approvals & Warranty

Certifications ASME Certified
Energy Efficient Yes (Green Certified)
Warranty 2 Years

What's in the Box

  • Pentair MasterTemp Digital IID HD ASME 250K Natural Gas Heater
  • Union Fittings
  • User Manual

Warranty

The MasterTemp Digital IID HD ASME 250K comes with a 2-year manufacturer warranty from Pentair. Clearflow Pool Supply is an authorized Pentair dealer and will assist with any warranty service needed.

Downloads

Frequently Asked Questions

How does this (461020) compare to the other 250K ASME model (460771)?

Both are ASME-certified 250K BTU MasterTemp natural gas heaters. The 461020 adds heavy-duty cupro nickel tubing — making it the full commercial spec for low pH, high flow, or heavy use applications. The 460771 uses standard heat exchanger materials and is suitable when ASME certification is required by code but HD tubing isn't needed for the water chemistry or application.

What does ASME certified mean for this heater?

ASME (American Society of Mechanical Engineers) certification means the heat exchanger was built to the most rigorous pressure vessel standards. Many commercial pool installations — hotels, fitness centers, aquatic facilities — require ASME-certified heaters per local code.

Does this heater require professional installation?

Yes. Gas heater installation involves connecting to a natural gas supply line, electrical wiring, and proper venting. A licensed contractor must perform the installation to ensure safety, local code compliance, and warranty validity.

Can it be used indoors?

Yes. The MasterTemp is rated for both indoor and outdoor installation. Indoor installations require proper venting per local code. Consult the operating manual and a licensed contractor for indoor venting requirements.

Shipping

Shipping Policy

At ClearFlow Pool Supply, we keep things simple.

👉 Free shipping on all orders within the United States.
No hidden fees. No surprises.


Order Confirmation

As soon as you place your order, you’ll receive an order confirmation email.

This means:

  • we’ve received your order
  • your payment method has been pre-authorized

Once your order is in our system, we verify:

  • product availability
  • inventory status with our suppliers

If an item is unavailable or backordered, we will:

  • void the pre-authorization
  • contact you promptly to discuss alternatives

If your item is in stock and ready to ship (typically within 3–5 business days), your order will be processed and prepared for shipment.


Order Shipment

Orders that are in stock will typically ship within 3 business days.

You will receive a shipping confirmation email with tracking details within 24 hours of your order leaving the warehouse.

If you do not receive tracking information within 4 business days, please contact us at:

👉 support@clearflowpoolsupply.com 


Shipping Scope

We currently ship to customers within the United States.

Due to the size and nature of many pool equipment products, some orders may ship via freight carriers. Delivery times may vary depending on location and product availability.


International Orders

At this time, our products are designed and configured for the U.S. market, operating on 110V electrical systems and meeting U.S. safety standards.

We may be able to accommodate international orders on a case-by-case basis.
If you are located outside the United States, please contact us to request a custom shipping quote.


Damaged Shipments

Please inspect your order upon delivery.

If you notice any damage:

  • note it with the carrier before signing
  • or refuse the delivery if damage is severe

If you accept the delivery:

👉 Take clear photos of:

  • the packaging
  • the damaged product

Then email us immediately at:

👉 support@clearflowpoolsupply.com

We will work with you quickly to resolve the issue.


Returns

For full details on returns, please visit our Returns Policy page.

Why Buy from Us

Why Buy From Us

We understand—you have options when it comes to buying pool equipment online.

At ClearFlow Pool Supply, our goal is simple:

👉 provide reliable products
👉 offer a straightforward buying experience
👉 and support you every step of the way

Here’s what sets us apart.


Free Shipping Across the U.S.

No hidden fees. No surprises.

All orders ship free within the United States, including large and heavy equipment.


Competitive Pricing

We work to offer strong, competitive pricing across our entire catalog.

If you find the same product available online at a lower total price, feel free to reach out—we’re happy to review it.


30-Day Return Policy

If your product isn’t the right fit, we offer a 30-day return window.

We aim to make the process as simple and straightforward as possible.
(See our Returns Policy for full details.)


Reliable Equipment

We focus on products that matter:

  • durable
  • proven
  • built for long-term use

Our goal is to help you avoid the frustration of unreliable or low-quality equipment.


Customer-Focused Support

We’re here to help before and after your purchase.

Whether you’re:

  • replacing a component
  • upgrading your system
  • or choosing equipment for the first time

👉 we’re here to make the process easier


Our Commitment

We stand behind what we sell.

If something isn’t right, we’ll work with you to resolve it quickly and fairly.


Price Match Policy

If you find the same product offered at a lower total price (including shipping), contact us at:

👉 support@clearflowpoolsupply.com

We’ll review the offer and do our best to match it.