Brita Professional – How To Flush Your Filter

If your Brita Professional water filter has been sitting unused for a period of time — whether due to a business closure, seasonal shutdown, or a machine that has been out of service — flushing the filter before resuming use is an important step. Brita filtration systems are designed for continuous use. When flow stops for an extended period, the filter media can become stagnant, which affects both water quality and the performance of your coffee machine.

This guide covers when and how to flush a Brita Professional filter, including the Brita Purity and Purity C range used in most commercial coffee machine setups.

When Should You Flush a Brita Professional Filter?

You should flush your Brita Professional filter in the following situations:

• New filter installation — all new Brita Purity and Purity C filters require an initial flush before use to activate the filter media and remove any carbon fines from manufacturing
• After a period of inactivity — if the filter has not had water running through it for 48 hours or more, flush it before resuming service
• After a machine service or descale — descaling chemicals can affect filter performance; always flush after any chemical process upstream of the filter
• After the filter has been disconnected — if the filter head or cartridge has been removed and refitted, treat it as a new installation

How to Flush a Brita Purity or Purity C Filter

The flushing process is straightforward and takes around five minutes. You will need access to the filter housing and a suitable drain or container.

1. Ensure the filter is correctly installed — check the cartridge is fully seated in the housing and the head is secure before running any water through it
2. Run cold water through the filter — open the bypass valve or flush port and allow cold mains water to pass through the cartridge continuously. For Brita Purity filters, flush with a minimum of 20 litres of water. For Purity C filters, Brita recommends flushing until the water runs clear
3. Check the flow rate — after flushing, the flow rate through the filter should be consistent with normal operation. A significantly reduced flow may indicate the filter is blocked or has been incorrectly installed
4. Reset the filter indicator — if your Brita head unit has a filter life indicator (such as the Brita Purity C Quell ST head), reset it after flushing a new cartridge so the remaining capacity is tracked accurately
5. Run a test draw through the coffee machine — before returning to service, run two or three full water cycles through the machine to ensure filtered water is reaching the boiler cleanly

How Often Should Brita Professional Filters Be Changed?

Filter replacement frequency depends on your local water hardness and daily water consumption. Brita Professional filters are rated by total water volume processed and by calcium carbonate reduction capacity. In hard water areas — which covers most of the UK Midlands, South East, and East of England — filters will need replacing more frequently than in softer water regions such as Scotland and the South West.

As a general guide:

• High-volume commercial sites (200+ cups per day) should check filter status monthly
• Office and low-volume sites should check every 3–6 months
• Always replace before the filter capacity is fully exhausted — a depleted filter offers no protection against scale and may allow hardness to pass directly into the boiler

If you are unsure of your local water hardness, a simple water hardness test strip will give you a reliable reading in under a minute.

Why Water Filtration Matters for Coffee Machines

Limescale is the primary cause of boiler failure, heating element damage, and inconsistent brew temperature in commercial coffee machines. In hard water areas, an unprotected machine can accumulate significant scale within weeks of regular use. A correctly maintained Brita filter reduces the minerals responsible for scale, extends machine life, and helps maintain consistent extraction temperature — all of which directly affect drink quality.

We supply a full range of Brita Professional filters, replacement cartridges, and water filtration accessories for commercial espresso machines, bean-to-cup units, and filter coffee equipment. If you need help identifying the right filter for your machine, contact our team and we can advise.