GRL Direct

How do I change the filter cartridge on my Omni tap?+
To download an illustrated guide to changing your OMNI Duo system’s filter cartridge, please click here.
1. Operate the switch on the front of the boiler to switch off the boiler power supply.
2. Shut off the water supply to the filter using the adjacent stop-valve.
3. Press the red button at the top of the filter unit to exhaust the pressure in the system. It will not be possible to unscrew the filter canister if this operation is not carried out.
4. Place a shallow container in the cabinet to catch any water residues when removing the filter sump. Grip the sump (the lower part of the filter cartridge housing) and turn it firmly to the left to break the seal. Unscrew the sump by hand until it separates from the head of the filter.
5. If the old cartridge does not automatically release itself, press down on the top mount of the cartridge. Remove the old cartridge and discard any residual water in the sump.
6. Remove the new filter cartridge from its packaging, wet the “O” seal and place it in the filter sump. Position the sump, with the cartridge inside, under the filter head and screw it in place. The cartridge should engage automatically. Tighten the sump, sufficient to make a water tight seal. Important Note: finger tight only should be sufficient, do not overtighten.
7. Turn the water supply on and check the system carefully for leaks.
8. Operate the system and run the filtered water for a few moments until the water runs clear. Run the boiling water for a moment to release any trapped air.
9. Turn the boiler power supply back on.
10. Press and hold the reset button on the filter change indicator module installed underneath the sink to reset the timer. The module will beep to indicate a successful re-set after a few seconds of holding the button down.
My tap’s boiler tank seems to have stopped producing boiling water+
In certain circumstances, there is a safety reset mechanism on your OMNI Duo’s boiler tank that will cause it to shut down. Examples of where a tank will shut down include if there is no water in the tank or if there has been a power surge. Firstly, check the power supply to the tank. If this is satisfactory, try resetting your boiler tank. This is a simple procedure. Watch our easy-to-follow video here.
If, after following this reset procedure, you are still experiencing problems, please call or email the FilterFlow tech team for further assistance.
My tap spits and splutters+
If you’re new to boiling water taps, their water delivery can take some getting used to. In fact, this question is probably one of our most common customer enquiries!
However, it’s important to remember that the boiling water flow will never be smooth as a normal hot or cold flow. It is, after all, being dispensed from the tap’s spout at a boiling temperature and accordingly, you should always expect to experience some steam and perhaps, some spluttering.
Ensure you use your OMNI Duo tap in a safe manner. When filling containers, place the receptacle high up under the tap so that the end of the tap’s spout is contained. This is the best and safest way to use your OMNI Duo tap – containing the boiling water and preventing any splashes.
I still think my tap is spitting and spluttering too much…+
If you still feel your OMNI Duo tap is spluttering excessively, there are some simple checks you carry out to ensure the pattern of the boiling water flow is optimised.

1.) Remove your OMNI Duo tap’s filter cartridge from its housing and run the tap’s boiling water flow without the filter cartridge. If you see a marked improvement in the flow’s pattern, it indicates your tap’s filter cartridge is partially blocked, thus impeding the flow. The recommended replacement cycle is every 6 months, but as water quality varies from area to area, this can of course be more frequent.
2.) Check when your filter cartridge was last replaced – the recommended replacement cycle is every 6 months – but as water quality varies from area to area, this can of course be more frequent.
3.) Look at the flexible hoses that connect your OMNI Duo tap to its boiler tank. Check they have not become kinked.
4.) Check that the green-handled stop valve that is connected to the Mains water supply is fully open. If it is, the lever should be fully aligned with the pipework.
5.) Check your water pressure, using a proper gauge. Your OMNI Duo tap system requires a minimum water pressure of 1.5 bar and pressure should not exceed 5 bar. 3-4 bar pressure is ideal for optimum performance. Do take care to measure water pressure accurately.
The flow of tap’s boiling or filtered water seems slow…+
If the boiling or filtered water flow of your OMNI Duo tap seems slow or restricted, it might indicate your tap’s filter cartridge needs replacing. Filter cartridges should be replaced every 6 months. However, it’s worth remembering this is a recommendation only – water quality varies from area to area – and in some areas, there will be higher turbidity (particle contamination). This means your OMNI Duo tap’s filter cartridge might need replacing more regularly. It’s also good to remember that as well as your OMNI Duo tap’s filter cartridge keeping your water free from contaminants, it is also helping to minimize limescale deposits. This in turn ensures your tap’s boiler tank can deliver optimum performance.
To find out if a blocked filter cartridge is the reason for your tap’s poor boiling water flow, remove the filter cartridge and use the tap’s boiling water function without the cartridge. If you see the flow has returned to normal, purchase a replacement filter cartridge FR08.
If this test does not resolve the problem, please call or email the FilterFlow Customer Support team for further assistance.
The boiler tank trips and shows two green lights – what should I do?+
Please contact us, if, having checked your tank’s power supply, it continues to trip and displays two green lights.
My tap is leaking from the base of its tank+
If the flat silicone washer or the tapered silicone washer on the top of the tank unit is out of position or damaged, water can run down the inside of the casing causing a leak at the base. You will need to replace the washer so please call or email the FilterFlow tech team so that we can provide replacements.
The instructions below show you how to fit your replacement washers.
1.) Firstly, switch off the power to the heating tank (the switch is located on the front of the tank), then unplug the tank from the mains.
2.) Open the boiling water handle on the tap and run until cold water comes through. Also, open the hot/cold handle to make sure there is no residual water in the tap.
3.) Next to the filter housing is a green lever. Turn this to turn off the water supply to the tank.
4.) You’ll then need to release the pressure from the tap. Do this by opening the boiling water handle again.
5.) If the black NutRunnas^® have been installed, undo both the red and green hoses. Either use the nut runners provided or, if they have not been installed, use a small adjustable spanner.
6.) Inspect the existing washers for damage.
7.) In the pack from FilterFlow there will be a tapered washer, which should be positioned on the tank before attaching the hose (refer to diagram for washer location). After this, attach the green hose to the tank with the flat washer. Ensure the red and green hoses are not overtightened.
8.) Turn on the water supply by turning the green lever located next to the filter housing.
9.) To allow air to be released from the tap, open the boiling water handle until there is a smooth, continuous flow of water.
10.) Plug in the tank and turn the power back on. Wait for around 20 minutes to allow the water to heat up. This will be apparent when the light on the front of the tank turns from red to green.
Deposits or foam are forming on the surface of my hot drinks+
The purpose of your OMNI Duo tap’s filter cartridge is three-fold – to protect the boiler tank from limescale deposits in hard water areas (50% of the UK), to prevent erosion in soft water areas and to remove chlorine, heavy metals and sediment from your water.
However, the filter cartridge will not stop the froth appearing on the surface of hot drinks that is caused by the calcium and magnesium deposits that occur in many hard water areas.
Unsightly deposits on the surface of a cup of tea
The purpose of your OMNI Duo tap’s filter cartridge is three-fold – to protect the boiler tank from limescale deposits in hard water areas (50% of the UK), to prevent erosion in soft water areas and to remove chlorine from your water. However, the filter cartridge will not stop the film appearing on the surface of hot drinks that is caused by the calcium and magnesium deposits that occur in many hard water areas.
If the film is unacceptable, you might like to try an alternative filter cartridge – the FR06. However, it is wise to bear in mind that the cartridge will need replacing much more frequently. For tea, some FilterFlow customers find that using specialist hard-water teabags, or teabags made from organic, natural material can also minimize the problem.
My hot drinks have a froth on their surface
Sometimes, a light foam or froth on the surface of hot drinks can be seen and this is the result of the millions of tiny air bubbles that are produced by the boiling water combining with the ‘base’ of the drink – e.g. hot chocolate powder or instant coffee granules. With tea, it is often the tiny amount of oil in the tea bag that creates the froth – and it can look unsightly. Try using a teapot with loose leaf tea, putting the boiling water into your cup followed by the tea bag or switching to unbleached or organic tea bags.
There’s a little red light flashing on my tap – what is it and what should I do?+
It’s nothing to worry about. The flashing light is simply telling you that your tap’s filter cartridge is due for replacement. Your OMNI requires a Franke 08 filter cartridge, which you can purchase here. Remember that your tap’s filter cartridge does two, very important jobs – it removes chlorine from your cold filtered drinking water – and it also works to minimise limescale deposits. Limescale, which is caused by hard water, is the enemy of heating elements, so ensuring your OMNI boiler tank’s element is not damaged by limescale is very important indeed.

Once you’ve changed your filter cartridge, don’t forget to re-set your tap’s filter cartridge replacement indicator module (you’ll find it under the sink). Simply press and hold the button on the module for 5 seconds to re-set it.
The little LED on my tap is glowing yellow – what does it mean?+
Don’t worry. If the LED light on your tap is glowing yellow, it means the batteries in your tap’s filter cartridge replacement indicator module (positioned under the sink) require replacing. The indicator module needs 2 x AAA batteries. When you fit the module’s new batteries, there should be an audible ‘beep’. The LED light on your tap will initially flash red, then glow yellow and should then turn off.

Omni Duo