Which Water Filter Do I Need?
Most of what's in your cup is water, so it pays to get it right. Tap water carries minerals that slowly build up as scale inside your machine (think of the white crust in your kettle), plus chlorine that flattens the flavour. A good filter sorts out both. Four steps below, or let the filter selector do the thinking for you. We're the New Zealand distributor of BWT water filters.
Four steps to better water
Check your water
"Hardness" is just the amount of minerals (mostly calcium) in your water, the stuff that turns into scale. Good news: most NZ town water is soft. Auckland's main supply sits around 23 mg/L and Wellington's 18–47 mg/L. Bore, tank and rural water can be a different story, around 120 mg/L in Waiuku. Your council's water quality report will tell you, or we're happy to test it.
Pick the type of filter
Espresso machine plumbed into town water: bestmax PREMIUM. Hard, bore or tank water, or a combi oven: bestprotect. A machine with a water tank you fill by hand: a BWT filter jug. More on each below.
Pick the size
Each filter is good for a set number of litres. Change it when it gets there or after 12 months, whichever comes first. On soft town water the calendar usually wins, so pick a size that'll see out the year.
Add a filter head
The filter head is the bit on your water line that the cartridge (the replaceable filter) screws into. Buy it once, then just swap cartridges when they're due. The BWT besthead Filter Head & Flush Kit has everything you need.
Find your filter
Stops scale and adds a touch of magnesium, which helps coffee taste its best. Our go-to for most machines.
The tougher option. Guards against scale and the corrosion hard water can cause.
RO water is so pure it makes flat coffee. This puts back the minerals coffee needs to shine.
Takes out chlorine taste, odd smells and sediment (fine dirt).
Filter it before it goes in the tank. No plumber required.
Tell it how much water you use and how hard it is, and it'll do the maths.
How big a filter? (bestmax PREMIUM)
Based on soft town water (up to 125 mg/L) and a 12-month change. Coffee counts are a rough guide and include steam and rinsing water. Harder water uses a filter up faster; the filter selector works that out for you.
Rather leave it to us?
We'll fit it for you
Our Auckland technicians can install your filter, test your water and set it up just right. Book a home machine service or a commercial service.
Trade pricing
Running a café, fitting machines or reselling? Apply for a wholesale account for trade prices and box-quantity discounts.
Good questions
Which water filter does my espresso machine need?
For most espresso machines plumbed into New Zealand town water, BWT bestmax PREMIUM is the right choice. It stops scale building up and adds a little magnesium, which brings out the flavour in coffee. If your water is hard (bore, tank or rural water) or you're filtering for a combi oven, choose BWT bestprotect. If your machine has a water tank you fill by hand, use a BWT filter jug instead.
Why filter water if it's already soft?
Even soft water carries a little of the stuff that forms scale, plus chlorine and fine sediment. Over a year that adds up inside boilers, pipes and valves, and chlorine flattens the flavour. A filter keeps your machine happier for longer and your coffee tasting the way it should.
How often should I change my water filter?
Change the cartridge when it has filtered its rated number of litres, or after 12 months, whichever comes first. On most New Zealand town water the 12 months comes first, so choose a size that covers a year of use.
How hard is Auckland water?
Auckland's water is soft. Watercare's 2024/25 water quality report puts the main supply at about 23 mg/L total hardness. Some bore supplies, such as Waiuku, are much harder at around 120 mg/L.
Do I need a filter head?
Yes. The cartridge screws into a filter head that's fitted to your water line. You buy the head once (our BWT besthead Filter Head & Flush Kit includes everything), then you only replace the cartridge.
Can you install my water filter?
Yes. Our Auckland technicians can fit your filter, test your water and set it up correctly as part of a home or commercial service.
Can I buy BWT filters at trade prices?
Yes. Machine Ltd is the New Zealand distributor of BWT water filters. Cafés, technicians and resellers can apply for a wholesale account to see trade prices and box-quantity discounts online.