Pentair Manifold O-Ring Kit for Max-E-Therm and MasterTemp Heater Water System 77707-0120
Pentair
SKU: 77707-0120
Pentair 77707-0120 O-Ring Kit for MasterTemp and Max-E-Therm Heaters
The Pentair 77707-0120 O-Ring Kit is a genuine replacement sealing kit used on compatible Pentair MasterTemp and Sta-Rite Max-E-Therm pool and spa heaters. This kit is used in the heater water system to help reseal the manifold/header and tube sheet area during service or repair.
Replace worn, flattened, cracked, or leaking O-rings to help restore a proper watertight seal and prevent water leaks around the heater manifold assembly. This kit is commonly used when servicing the heat exchanger, manifold, or tube sheet area of compatible MasterTemp and Max-E-Therm heater models.
Product Features
- Genuine Pentair replacement part
- Manufacturer part number: 77707-0120
- Replacement O-ring kit for compatible heater water system repairs
- Used with Pentair MasterTemp and Sta-Rite Max-E-Therm heaters
- Helps seal the manifold/header and tube sheet area
- Ideal for leak repair or heater manifold service
- Designed for proper fit and sealing in compatible Pentair heater assemblies
Product Details
| Brand | Pentair |
| Part Number | 77707-0120 |
| Product Type | Heater O-Ring Kit |
| Application | Pool and spa heater water system sealing |
| Common Use | Manifold/header and tube sheet sealing repair |
Compatibility
- Pentair MasterTemp pool and spa heaters
- Sta-Rite Max-E-Therm pool and spa heaters
- Select ASME heater water system applications
Installation Notes
- Turn off power and gas to the heater before servicing.
- Allow the heater to cool completely before disassembly.
- Relieve system pressure and drain water from the heater before removing manifold components.
- Clean sealing surfaces before installing new O-rings.
- Use only pool-safe silicone lubricant on O-rings when needed.
- Do not overtighten manifold hardware, as uneven pressure can cause leaks or damage.
- After installation, restore water flow and check carefully for leaks before returning the heater to normal operation.
Related Products
- Pentair MasterTemp Heater Manifold Bypass Valve Kit | 77707-0001
- Pentair MasterTemp & Sta-Rite Max-E-Therm Thermal Regulator Kit | 77707-0010
Maintenance Tips
- Inspect the heater manifold area periodically for small leaks, mineral buildup, or corrosion.
- Repair leaks promptly to help prevent additional heater damage.
- Maintain proper pool water chemistry to reduce scale buildup and extend heater component life.
- When replacing heater seals, inspect nearby components such as the bypass valve, thermal regulator, drain plug, and pressure relief valve for wear.
Questions about returns? View our return policy.
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.
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