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Frequently asked questions

Answers to the questions customers ask us most, from choosing and fitting a dimmer to curing flicker. Search, or browse by product or topic.

Showing 36 questions about V-Com Show all questions

Choosing a dimmer

Which dimmer suits your lights, how much lighting it can take, and dimming from more than one switch.

Which dimmer do I need for my LED bulbs?

For dimmable LED lighting choose a V-Pro dimmer: our flagship range, designed for modern LED lighting, with push on/off switching and rotary dimming. In the European ranges the V-Pro family also includes:

  • V-Pro Multiway: a dimming knob at 2 or 3 switch positions;
  • V-Pro Micro: hidden behind retractive (push) switches.

If your LED lights or driver need leading-edge (triac) control, choose V-Com. Always choose lamps that are described as dimmable.

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How many lamps can my dimmer control?

Add up the wattage of all the lamps the dimmer controls: the number of lamps times the watts printed on each. The total must not be more than the maximum load per gang on the dimmer's label and data sheet. For example, 8 LED downlights of 5W each add up to 40W.

DimmerLoad per dimmer (gang)
V-Pro0-120W or 0-300W, no minimum load
V-Pro Multiway120W (master dimmers 100W), no minimum load
V-Pro Micro160W of dimmable LED
V-Com0-100W, 0-180W or 15-180W (the first figure is the minimum)
V-Dim (halogen)60-400W, or 40-250W on 2-gang dimmers

With low voltage lighting, add up the VA ratings of the transformers, not the wattage of the bulbs.

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Is there a minimum load? Can I dim just one LED lamp?

V-Pro, V-Pro Multiway and V-Pro Micro dimmers have no minimum load, so they can dim a single LED lamp.

Some V-Com dimmers and every V-Dim dimmer have a minimum: it is the first figure of the rating on the label, for example 15-180W. The 0-100W and 0-180W V-Com dimmers have none. Below the minimum the lights may flicker: see flicker caused by too little load.

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My LED driver says "triac" or "leading edge": which dimmer do I need?
  • Triac or leading edge: choose V-Com, designed for LED lighting that needs leading-edge (triac) control. V-Pro dimmers are not suitable for triac dimmable drivers.
  • Trailing edge: choose a V-Pro dimmer.
  • 1-10V: choose an F-Series 1-10V dimmer.

If you are unsure which control your lamps need, check the lamp or driver manufacturer's data sheet, or ask us for advice: send us a message or email help@varilight.co.uk.

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Is a V-Pro dimmer 1-way or 2-way?

Both. Each V-Pro dimmer has three terminals, C, L1 and L2, and works on 1-way circuits (one switch) and 2-way circuits (two switches, e.g. top and bottom of the stairs). V-Com dimmers are the same.

On a 2-way circuit replace only one of the switches with the dimmer: you dim from that switch, and the other switch turns the lights on and off. See how to wire it. To dim from every switch, see dimming from more than one switch.

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Can I mix lighting types on the same dimmer?

VARILIGHT dimmers are not designed to handle mixed lighting types on a single circuit. This includes combining halogen and LED lamps. With halogen lamps being phased out, most installations now use only dimmable LEDs, which ensures optimal performance and reduces the risk of overload.

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Will my LED lamps work with your dimmers?

Our dimmers are designed for wide compatibility and are tested with many lamp types, including Megaman and Philips, which have performed well in testing. However, due to constant changes in LED technology and driver designs, we cannot guarantee compatibility with all lamps.

Before purchasing, please check our compatibility guide and the dimmer selection guide to make sure the lighting load you have is compatible with the dimmer you have chosen.

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Can I replace just the dimmer module in my existing plate?

Yes. Our European replacement dimmer modules fit our European dimmer plates. Remove the knob and the front plate, unscrew the nut, take the old module out from the back and fit the new one.

Each module is 64 x 58 x 46mm. Its data sheet shows the instructions and where to buy it.

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Setting up and programming

Dimming modes, minimum and maximum brightness, resets, and pairing supplementary controllers, remotes and the app.

V-Pro and V-Com rotary dimmers

How do I change the dimming mode on a V-Pro or V-Com dimmer?

V-Pro dimmers have three modes: Mode 1 trailing edge (the default, best for most LEDs), Mode 2 simulated leading edge, not triac (certain LEDs) and Mode 3 alternative trailing edge (some LEDs). On V-Com dimmers Mode 1 is recommended; if you notice any flashing, try Mode 2 or, in some cases, Mode 3.

  1. Set the knob to maximum (MKP100 module: a high brightness level). Switch the lights off and on once per second, 3 times (6 presses of the knob in all), to enter configuration mode.
  2. For Mode 2: turn the knob fully anticlockwise and wait 2 seconds.
    For Mode 3: turn it fully anticlockwise, then fully clockwise, and wait 2 seconds.
  3. The lights flash to confirm: once for Mode 1, twice for Mode 2, three times for Mode 3.

To go back to Mode 1, reset the dimmer to factory settings. If Mode 2 draws too much current, the dimmer goes back to Mode 1 by itself.

These steps are for current dimmers. Older dimmers may be programmed differently: check the software version on the side of the module and use the matching leaflet from the instruction leaflets or earlier leaflets page. There is a programming video on VARILIGHT TV, and the steps for every range are in set up your dimmer.

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How do I set the minimum brightness on a V-Pro or V-Com dimmer?

If your lights flicker at low brightness, raise the minimum. If they are too bright at the lowest setting, lower it.

  1. Turn the dimmer to a low brightness level (MJP120 and MJP300 modules: fully anticlockwise).
  2. Switch the lights off and on once per second, 3 times.
  3. The lights "step" up and down to confirm you are in configuration mode.
  4. Turn the knob fully clockwise to begin the adjustment.
  5. Slowly turn the knob down and up until you find your preferred minimum brightness.
  6. Leave the knob in this position: after 5 seconds the setting saves automatically.

Make sure all the lamps stay visibly on at the lowest setting (EU Ecodesign Regulation 1194/2012). Can't get into configuration mode? Child lock may be on. Other ranges: set up your dimmer.

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How do I set the maximum brightness on a V-Pro or V-Com dimmer?

If the lights flicker at high brightness, lower the maximum. If they aren't bright enough, you can raise it.

  1. Set the dimmer to maximum (fully clockwise).
  2. Switch the lights on and off once per second.
  3. Set the knob to minimum, then switch on and off again.
  4. Return the knob to maximum and switch the lights on.
  5. In configuration mode, turn the knob fully anticlockwise to begin the adjustment.
  6. Slowly turn the knob until you find your preferred maximum brightness.
  7. Leave it for 5 seconds to save.

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What is child lock, and how do I turn it on or off?

Child lock stops the dimmer going into programming mode by accident. If you can't get the dimmer to program, turn child lock off first. On V-Pro and V-Com dimmers:

  1. Set the knob to maximum and switch on and off twice.
  2. Set the knob to minimum and switch on and off twice.
  3. Set the knob to maximum and switch on, off, on.
  4. The lights step to confirm the lock is on.

Repeat the same steps to turn it off. V-Pro Multiway: see Multiway programming. Watch the child lock video on VARILIGHT TV.

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I've changed the bulbs on my dimmer: do I need to do anything?

Yes. Always turn off the mains power before replacing bulbs controlled by a dimmer. If you have changed the type of bulb, reset the dimmer to its factory settings: see V-Pro and V-Com, V-Pro Multiway or V-Pro Micro in set up your dimmer.

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How do I reset a V-Pro or V-Com dimmer to factory settings?

A reset restores Mode 1 and the original brightness settings.

  1. Set the knob to maximum and switch off and on 3 times, about once per second.
  2. Wait at least 3 seconds, then switch off and on 3 times again.
  3. The lights fade off: the reset is complete.

If the dimmer won't respond, child lock may be on. Resetting another range: set up your dimmer.

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Some LEDs won't come on at low brightness: what is Drive (Boost)?

Drive gives LEDs that won't switch on at low brightness a short boost at start-up. On V-Pro and V-Com dimmers:

  1. Set the knob to minimum.
  2. Switch the lights on and off once per second.
  3. Set the knob to maximum, and switch on and off again.
  4. Set the knob to minimum and switch the lights on.
  5. In configuration mode, turn the knob up until the lamps switch on.
  6. Leave it for 5 seconds to save.

To turn Drive off, repeat the steps but skip step 5. The same feature is called Boost on V-Pro Multiway and on the V-Pro Micro, where it is set from the switch: see set up your dimmer.

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Fitting and wiring

Wiring 2-way and multi-way circuits, wall box depths and where to find the instructions. If in doubt, consult a qualified electrician.

Dimmers

How do I wire a V-Pro dimmer on a 2-way circuit?

Switch off at the mains first. If in doubt, consult a qualified electrician.

  1. Replace only one of the two switches with the dimmer (fitting two dimmers causes flicker). Note the position of each wire on the old switch, and keep any wires that were grouped together in one terminal together.
  2. The wire(s) from the common terminal of the old switch go into C.
  3. The other two wires go into L1 and L2, either way round.
  4. For metal faceplates, connect the earth wire to the marked earthing terminal.
  5. Fit the dimmer into the wall box without overtightening, check no wires are trapped behind it, restore the power and test.

1-way circuit (one switch): one wire into C, the other into L1 (either way round); L2 is not used.

More than one dimmer on the plate: treat each set of three terminals as a separate dimmer. If the old switch had terminals linked between gangs, link the same terminals on the dimmer with a short wire.

Diagrams are in the V-Pro instructions (PDF), and there is a V-Pro video on VARILIGHT TV. V-Com dimmers are wired the same way: see the V-Com instructions (PDF).

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What wall box do the European ranges need?

The European fixed range and the European VariGrid range fit a standard European 40mm round or square wall box. Fix them with the screws or the claws supplied: see fitting a European fixed range product, fitting a VariGrid plate and the European fitting instructions (VEU001) on the instruction leaflets page.

The wall box for a particular product is also on its data sheet: type the product code into the search box. See also wall box depths.

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Where can I find the instructions or a wiring diagram for my product?

The instruction leaflet, with its wiring diagrams, comes with your product. You can also find every current leaflet on the instruction leaflets page, and leaflets for older and discontinued products on the earlier leaflets page. Where relevant, check the software version and choose the correct leaflet: the software version is on the side of the dimmer module.

We also have a page of wiring diagrams and how-to videos. Every data sheet links to the product's leaflet: type the product code into the search box. If the wiring diagram is not enough, please contact a qualified electrician.

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What do I need to remove before an insulation test?

Dimmers from all of our ranges should be disconnected for the duration of the insulation resistance test. Failing to do so could damage the dimmer and make the product guarantee invalid.

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Parts, finishes and care

Knobs and spare parts, product codes and data sheets, finishes, cleaning and decorating.

Where can I get a replacement dimmer knob?

All our knobs have the same fixing, so they fit every VARILIGHT dimmer. Screwless products need a "pipped" knob, which is slightly raised for spacing. Pipped knobs aren't sold separately: for a replacement, please send us a message or email help@varilight.co.uk and our customer services team will help.

Spare knobs are sold singly or in packs of 10 (the same code with 10 on the end). Click a code for its data sheet, which shows where to buy it:

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How should I protect my switches and sockets when decorating?

Do not use masking tape on any decorative products. The adhesive may chemically bond with the surface finish.

For Screwless products we recommend removing the faceplate and taking care not to paint over the plastic clips, as this may prevent the faceplate from clipping back on.

For products with visible fixing screws we recommend turning off the mains power, removing the fixing screws and pulling the product gently away from the wall, taking care that the wires remain fully fixed into their terminals.

When the product is clear of the wall, cover it with a plastic bag and use an elastic band to secure it behind the product. You can then paint or wallpaper the wall.

Please note that it can take several weeks for the chemicals in paint or wallpaper paste to become inert. Before this time there is a danger that they will react with the product if it has a metal faceplate. For this reason we recommend using a plastic bag as a temporary gasket between the product and the wall once it is dry to the touch. In other words, use the plastic to form a barrier between the product and the surface of the wall.

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A knob, screw or other part is missing or broken

Please send us a message or email help@varilight.co.uk, telling us the product code and what is missing or broken, and we will sort it out.

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My switch or socket has begun to tarnish

Cu29 raw copper is designed to tarnish: a natural patina develops without regular cleaning. To brighten it, wipe lightly with a little citric acid on a polishing cloth, and never coat it.

On other finishes, tarnishing is usually caused by damp. The source of the damp may be a damp wall. In this case you can prevent further tarnishing by placing a plastic barrier between the product and the wall (for example a piece cut from a clear plastic bag).

If the surface of the product has been damaged, for example during cleaning, then damp may have permeated and caused tarnishing of the faceplate. Unfortunately in this case the product is permanently damaged.

If you have recently decorated, please note that it can take several weeks for the chemicals in paint or wallpaper paste to become inert. Before this time there is a danger that they will react with the product if it has a metal faceplate. For this reason we recommend using a plastic bag as a temporary gasket between the product and the wall once it is dry to the touch.

If your products are permanently damaged it may be that you can claim on your house insurance for replacement products.

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Guarantee and older products

The lifetime guarantee, how to claim, and help for products we no longer make.

How do I make a guarantee claim or return a faulty product?

Many problems can be solved without a replacement, so please check the troubleshooting answers first. Then:

  1. Send us a message, or email help@varilight.co.uk, with your purchase details and a description of the problem. Tell us the product code, the batch number (on the plastic moulding at the back of a dimmer), the type and wattage of the lamps it controls, and the fault. Keep your proof of purchase.
  2. The faulty product must be returned: we'll tell you where to send it, to VARILIGHT in the UK or to Varilight Europe Kft in Hungary (both addresses are in the instruction leaflet). Pack it securely with your proof of purchase, your contact details and return address, the type and wattage of the lighting or other load, and the details of the fault.
  3. If the claim is approved, we'll repair or replace the product.

See our lifetime guarantee.

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Where do I find the batch number or software version?

The batch number is printed on the plastic moulding at the back of the dimmer module: on the side or the bottom, depending on the model. The leaflet has a space to record it, and it helps us give you the right technical support. Where it applies, the software version is on the side of the dimmer module: use it to choose the right instruction leaflet.

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One dimmer on my multi-gang plate is faulty: can I keep using the others?

Yes. It is perfectly in order to remove a faulty dimmer module from a multi-gang dimmer by pulling off the knob and unscrewing the nut under the knob (and removing the front plate first, on a Screwless product). You will then still have the remaining modules working while we service the faulty one. See how to make a claim.

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Troubleshooting

Dimmers that have stopped working, flicker, buzz or glow, and other problems with installed products.

Not working, or switching off

My dimmer has stopped working: what should I do?

Many faults can be cleared without replacing anything. Switch off at the mains before touching any wiring and, if in doubt, consult a qualified electrician.

  1. Reset the power. Switch the lighting circuit off at the circuit breaker, then back on after a few seconds. An overloaded dimmer switches itself off to protect itself.
  2. Check the load. Add up the wattage of all the lamps on the dimmer (for low voltage lighting, the VA ratings of the transformers). It must not be more than the maximum per gang on the dimmer's label. See how many lamps a dimmer can control.
  3. Changed the bulbs? If you have changed the type of lamp, reset the dimmer to its factory settings: see set up your dimmer.
  4. New installation? Check the wiring against the diagram in the instruction leaflet.
  5. Lights come on but won't dim? See my dimmer won't dim the lights.

If it still doesn't work, the dimmer may be faulty. It is covered by our lifetime guarantee: see how to make a claim. It helps to have the product code, the batch number (printed on the plastic moulding at the back of the dimmer) and the type and wattage of your lamps to hand.

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My dimmer turns the lights on and off but won't dim them

V-Pro and V-Com dimmers: we would advise you to perform the factory reset on the dimmer switch. Instructions are also in the product instruction leaflet and on VARILIGHT TV. If you have performed the factory reset and the lights are still not dimming, please contact Customer Services: send us a message or email help@varilight.co.uk.

Other dimmers: this problem is usually caused when one of the components in the dimmer has failed, usually due to a plasma. Plasmas can be caused when a mains halogen light bulb (e.g. GU10) fails. For this reason we recommend only using good quality mains halogen bulbs from well-known brands. If a dimmer shows this fault it will need to be replaced.

The best type of dimmer to use with mains halogen bulbs is a VARILIGHT V-Plus series dimmer. The rapid on-board overload protection can usually turn the dimmer off so quickly that it survives a spike in the mains supply.

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My lights are switching to a reduced brightness

The usual reason is that the dimmer is overloaded. V-Pro and V-Com dimmers switch off until the overload is removed.

Check the maximum load on the label on the back of the dimmer. Add up the wattage of the lamps it controls; with low voltage lighting, add up the VA ratings of the transformers, not the bulbs. If the total is more than the maximum, use fewer or lower-wattage lamps, or a higher-rated dimmer: see how many lamps a dimmer can control.

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Flickering, buzzing and glowing

My LED lights flicker: how do I stop it?

Most flicker can be cured with the dimmer's own settings. On V-Pro and V-Com dimmers:

  • Flicker at low brightness: raise the minimum brightness.
  • Flicker at high brightness: lower the maximum brightness.
  • Flashing at any level: change the dimming mode. Mode 1 suits most LEDs; some perform better in Mode 2 or, in some cases, Mode 3.

Also check that the lamps are described as dimmable, and are all of the same type: our dimmers are not designed for mixed lighting types on one circuit; that on a 2-way circuit only one of the switches has been replaced with a dimmer; and, if your dimmer has a minimum load (the first figure of the rating on some V-Com and every V-Dim dimmer), that the lamps add up to more than it: see flicker caused by too little load.

V-Pro Multiway and V-Pro Micro dimmers have the same kind of settings: see set up your dimmer.

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My dimmer is causing the lights to flicker (minimum load)

This problem is usually caused when the dimmer is under-loaded.

Check the label on the back of the dimmer, where the minimum and maximum load are printed. Add up the ratings of all the light bulbs the dimmer controls and make sure they are more than the minimum. V-Dim dimmers work best with at least 100W. The 0-100W V-Com has no minimum.

If your lighting load is below the minimum, choose a different dimmer or use bulbs with a higher rating: you can still dim them right down. For dimmable LEDs choose a V-Pro dimmer: V-Pro dimmers have no minimum load.

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My lights won't dim low enough, or go off at the lowest setting
  • Too bright at the lowest setting: reduce the dimmer's minimum brightness.
  • Off or flickering at the lowest setting: raise the minimum brightness.
  • If some LEDs won't switch on at low brightness, turn on Drive (Boost), which gives them a short boost at start-up.

When the dimmer is installed, all the lamps must stay visibly on at the lowest brightness setting (EU Ecodesign Regulation 1194/2012). How low a lamp will dim varies according to the brand and type of LED. The same settings on V-Pro Multiway and V-Pro Micro (set from the switch): see set up your dimmer.

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My dimmer or my lamps are buzzing

It is quite normal for a dimmer switch to buzz a little. A dimmer is more prone to buzz with certain types of lighting load. If your lighting load is causing your dimmer to buzz excessively, we recommend changing the dimmer for a trailing-edge dimmer. Our V-Pro series trailing-edge dimmers are the quietest running dimmers available.

If the LED lamps themselves buzz while a V-Pro dimmer is on, a component within the lamps is vibrating during operation. Changing the driving mode on the dimmer may improve this. If the lamps continue to buzz after trying the different driving modes, we recommend contacting the LED manufacturer for further advice.

With other brands of dimmable electronic transformer, noise levels may vary depending on the type and quantity of transformers used.

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My lights flash 2 or 3 times before staying on

This happens when the dimmer detects too much current draw from the lamps on start-up, so it charges the lamps in steps in order to protect itself. Changing the driving mode on the dimmer may improve this behaviour. Instructions are also in the product instruction leaflet and on VARILIGHT TV.

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My LED lamps don't switch off when the dimmer enters programming mode

When the dimmer enters programming mode there is a small amount of current that passes through the module to allow the dimmer to be reconfigured. Some LED lamps are extremely sensitive and will glow even though the dimmer is effectively off. You should still be able to complete the programming procedure. If you are not certain, change one of the LED lamps for an ordinary halogen or filament lamp just for the duration of the programming, as this should stop the LED lamps glowing when they should be off.

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Is it normal for my dimmer to feel warm?

Yes. It is normal for dimmer switches to feel slightly warm during operation, particularly when they are controlling loads close to their maximum rated capacity. During dimming a small amount of heat is generated, and it is intentionally transferred to the front plate through the dimmer module's heat sink. This helps dissipate heat efficiently and protects the internal electronic components.

Touch and remote dimmers also draw a very small standby current when switched off, so they may feel slightly warm even when off. They have over-temperature protection, and the fire retardant material around the electronics at the back may show some discolouration from moderate temperatures, which is expected in normal operation.

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Still stuck?

Our customer services team will help. To get the quickest answer, tell us the product code, the batch number from the back of the dimmer, and the make, wattage and number of lamps.