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Primary Pro ASHP Pipe Insulation 22-42mm | AS022 | UV Proof
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£13.70
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£11.42
Exc. VAT
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The Primary Pro Heat Pump Pipe Insulation System is a purpose-built external pipe insulation range for air source heat pumps (ASHP), designed to protect the exposed flow and return pipework between the property and the outdoor unit. Unlike standard foam lagging, every length is supplied with a factory-applied, flexible waterproof coating that is UV and weather resistant straight from the box, so there is no on-site painting and no waiting for good weather.
Insulation is available for 22mm, 28mm, 35mm and 42mm pipework, and each length can be cut or mitred on site to suit runs, bends and external fittings such as isolation valves. It is engineered to pass through the fabric of the wall and be sealed with Primary Pro Bond & Seal, which keeps moisture out and heat in. Sealing matters as much as the insulation itself: the manufacturer notes that even a 1% rise in moisture content can increase thermal conductivity by 7.5%, directly eroding heat pump COP and SCOP.
The wider Primary Pro range completes the job, with pre-made elbows, Intatec valve jackets, wall sleeves, sealing rings, rubber-lined clips, back plates, joint covers, a maintenance coat, and the grinder head and diamond core bits needed for a clean, sealed wall penetration. Choose your size from the selector above and pick the accessories you need using the guide below.
UV & Weather
Resistant Straight From the Box
Waterproof
Factory-Applied Coating
4 Sizes
22, 28, 35 & 42mm Pipework
1m / 500mm
Lengths (42mm in Both)
Cut & Mitre
Shaped On Site
Through-Wall
Sealed With Bond & Seal
Wall Sleeves: External Walls Only
Primary Pro Sleeves are made from HDPE (PE80), which is not a fire-rated material. They are designed for external wall penetrations only and must not be used in fire-rated walls, floors or compartment structures. Always confirm your installation complies with the relevant building regulations for your project.
Seal Every Joint and the Heat Pump Connection
Insulation is only as good as its seal. Use plenty of Bond & Seal between the insulation and the pipe and on every joint face, then smooth and cap the outer joint. Always seal the connection to the heat pump casing too, because the cured sealant stays flexible and absorbs unit vibration. The manufacturer recommends a minimum of one 290ml tube per three 1m lengths of 28mm insulation (more for larger sizes). Using too little can lead to joint separation and water ingress.
Coastal and High-Corrosion Locations
Clips, back plates and fixings are zinc-plated steel. In coastal, high-salt or high-corrosion environments, additional protection or alternative fixing materials may be required, and exposed support components should be inspected as part of routine maintenance.
Maintenance: Recoat As and When Needed
After more than 8 years of real-world life testing, the manufacturer now recommends inspecting the insulation at the annual heat pump service and applying Maintenance Coat only if wear or discolouration is visible. Some installations, particularly those not facing south, did not need recoating within the first five years. The water-based coat also covers cured Bond & Seal.
Key Features
UV & Weather Proof Out of the Box
A flexible, factory-applied coating protects against sunlight, rain, frost and temperature swings, so installers can fit it in any weather with no painting on site.
Waterproof to Protect COP & SCOP
Wet insulation stops insulating. The waterproof coating and sealed-joint system keep moisture out of the foam, helping the heat pump hold its rated efficiency.
Cut, Mitre and Fit Any Fitting
Every length cuts and mitres on site for bends, tees and runs, and can be shaped around isolation valves and other external fittings.
Insulate Through the Wall
Designed to run through the fabric of the building, then sealed with Bond & Seal, so the pipework stays insulated right from the heat pump into the property.
Maintainable by Design
Easy to inspect at annual service and refresh with the water-based Maintenance Coat. The 22mm size shares the same clips and core bit as 28mm.
A Total-System Range
Elbows, valve jackets, sleeves, sealing rings, clips, back plates, joint covers, tools and coatings are engineered to work together, developed by installers for installers.
Insulation Sizes
Primary Pro insulation is supplied in 1m lengths, with the 42mm size also available in 500mm lengths for short runs and tight spaces. Select your size from the options above. Sizes below are the actual finished outside dimensions of the insulation.
Which Products Do I Need?
Match your pipe size to the components below. Every external pipe installation also needs Bond & Seal AS001, rubber-lined clips and a back plate.
Component Selector by Pipe Size
Intatec Valve Jackets
System Accessories in Detail
These items are part of the Primary Pro range and are available alongside the insulation. Specifications are taken from the manufacturer's technical data sheets.
Insulation Material Specification
Frequently Asked Questions
BTU & WATT Calculator
Room Dimensions
Room Type
Living Room
Bedroom
Kitchen
Bathroom
Conservatory
Hallway
Glazing Type
Single Glazed
Double Glazed
Triple Glazed
External Walls
0 Wall
1 Wall
2 Walls
3 Walls
4 Walls
Insulation Level
Poor
Average
Good (New Build)
Required Heating
0
Watts
0
BTUs
Do you have a question
about this product?
One of our expert advisors will be happy to help you!
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Tools & Kits
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Need a full system?
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