Davey Microlene 20" Jumbo Filter Housing - WaterMark Certified, High Flow, 25mm or 40mm Ports NZ

The Davey Microlene 20" jumbo filter housing accepts the largest cartridges available — delivering high dirt-holding capacity, strong flow rates, and longer intervals between cartridge changes. Available with 25mm (1") or 40mm (1½") ports to suit standard residential plumbing or larger rural and farm pipework.

Certified to WaterMark WMTS-103 (Lic. 032114) and tested in compliance with AS/NZS 4020 for use in contact with drinking water. Manufactured under ISO 9001 quality management and ISO 14001 environmental management systems.

Available as a housing only, or with a 20" jumbo cartridge included — select your port size and cartridge preference from the dropdowns.

Includes mounting bracket, screws, and housing spanner.

Bore water quality varies significantly. We recommend testing your bore water before selecting a filtration system — get in touch and we'll help you choose the right configuration for your supply.

Key specs at a glance

• Cartridge size: 20" jumbo (114mm / 4.5" diameter)
• Ports: 25mm (1") or 40mm (1½") female thread — select from dropdown
• Dimensions: 620mm H × 185mm W
• Max pressure: 880 kPa (128 psi)
• Water temperature: 0–40°C
• Max ambient temperature: 50°C
• Material: Reinforced polypropylene
• Colour: White
• Pressure relief valve: Yes
• Warranty: 1 year
• WaterMark WMTS-103, Lic. 032114
• Tested to AS/NZS 4020

Choosing your port size

25mm (1") ports — model W20J25MM
Suits standard residential mains connections and most tank water pump outlets. The right choice for the majority of NZ homes.

40mm (1½") ports — model W20J40MM
Suits larger pipework found on farms, lifestyle blocks, and high-flow installations where minimising flow restriction is important.

If you're unsure which port size matches your pipework, get in touch before ordering.

Why Kiwi homeowners choose Davey Microlene

• WaterMark certified and AS/NZS 4020 tested — verified for drinking water contact
• 20" jumbo cartridges deliver higher dirt-holding capacity and longer service intervals than 10" equivalents
• Two port size options — fits standard homes and high-flow rural installations
• Pressure relief valve for safe, clean cartridge changes
• Includes bracket, screws, and spanner — ready to install
• 1-year warranty backed by Davey's NZ dealer network

What do the certifications mean?

WaterMark WMTS-103 (Lic. 032114): Independently tested and certified against Australian and New Zealand water industry standards for plumbing products.

AS/NZS 4020: Tested in compliance with the standard for products used in contact with drinking water — covering materials, construction, and potential effects on water quality.

ISO 9001: The manufacturer operates a certified quality management system.

ISO 14001: The manufacturer operates a certified environmental management system.

Choosing a cartridge

20 micron pleated sediment
Removes sand, grit, rust, and coarse particles. High flow, cleanable and reusable. A good first-stage filter for tank, rainwater, and bore supplies.

1 micron polyspun sediment
Removes fine silt, dust, and rust particles. Physically blocks parasitic cysts. Ideal for polishing water or as a second stage after a coarse sediment filter.

5 micron carbon block
Removes chlorine taste, odour, and organic compounds. The right choice for town supply where taste and smell are the concern.

Not sure which cartridge suits your water? Get in touch and we'll help you choose.

Full technical specifications

Specification	W20J25MM	W20J40MM
Ports	25mm (1") female thread	40mm (1½") female thread
Cartridge size	20" jumbo (4.5" / 114mm od)
Height	620mm
Width	185mm
Max pressure	880 kPa (128 psi)
Water temperature	0–40°C
Max ambient temperature	50°C
Material	Reinforced polypropylene
Colour	White
Pressure relief valve	Yes
Certifications	WaterMark WMTS-103 (Lic. 032114), AS/NZS 4020
Quality systems	ISO 9001, ISO 14001
Warranty	1 year

What's in the box

• 1 × Davey Microlene 20" jumbo filter housing (port size per selection)
• 1 × Mounting bracket and screws
• 1 × Housing spanner
• Cartridge included if selected from dropdown

FAQ

What size cartridges does this housing take?

It takes 20" jumbo cartridges — 4.5" (114mm) outside diameter. Standard 20" cartridges (2.5" diameter) will not fit. If you're unsure, measure your existing cartridge's outside diameter before ordering.

What's the difference between the 25mm and 40mm port options?

Both housings are otherwise identical. The 25mm (1") port suits standard residential mains and tank supply lines. The 40mm (1½") port is for larger-diameter pipework on farms, lifestyle blocks, and high-flow installations where minimising flow restriction matters.

What's the advantage of 20" jumbo over 10" jumbo?

The 20" cartridge holds roughly twice the media volume — more dirt-holding capacity, longer service life, and sustained flow rates over a longer period. Worth the step up for high-demand or high-sediment supplies.

What does WaterMark certification mean?

WaterMark (WMTS-103, Lic. 032114) means the housing has been independently tested and certified to meet NZ and Australian plumbing standards. It's a mandatory certification for plumbing products in NZ and Australia.

What does AS/NZS 4020 mean?

It means the housing has been tested for use in contact with drinking water — covering the materials used and their effect on water quality.

Does it come with a cartridge?

The housing is available with or without a cartridge. Select your preference from the dropdown — housing only, or housing with your preferred 20" jumbo cartridge.

Why does it have a pressure relief valve?

The pressure relief valve releases pressure from the housing before you unscrew the bowl. Press it, hear the hiss, then unscrew — safe and splash-free.

How often do I need to change the cartridge?

It depends on the cartridge type and your water quality. Most cartridges are replaced every 6–12 months. A drop in flow rate or pressure is usually the first sign it's time.

Do I need a plumber to install it?

It connects via standard female thread fittings. Most customers use a licensed plumber for whole-house installations. Get in touch if you're unsure what's involved for your setup.

What warranty applies?

The housing carries a 1-year warranty. Cartridges are consumable items and are not covered by warranty, but get in touch if anything arrives damaged or defective.