Solving Dimplex Opti-Myst Problems: A Comprehensive Troubleshooting Guide

Common Faults in Dimplex Opti-myst Electric Fireplaces

In this guide, we’ll share our insights from fixing Dimplex appliances since 1976, and guide you through some of the most common Dimplex Opti-myst problems and provide helpful troubleshooting and maintenance tips. These innovative fireplaces, known for their stunningly realistic flame effects and efficient operation, occasionally encounter issues that can perplex even the most seasoned users. From the mystifying absence of the flame effect to unexpected maintenance hurdles, we’ll provide you with insider tips and proven solutions to ensure your Opti-myst fireplace continues to enchant your space without interruption.

Opti-myst Flame/ Myst Effect Not Working

Often Dimplex Opti-myst electric fireplaces fail to produce the characteristic “myst” flame effect, despite the water bottle being filled, this issue may lie with one of the following components:

Genuine Dimplex Transducer 1

Glass Disk Transducer: The glass disk transducer, which creates an ultra-fine water mist, is the component of the Opti-myst fireplaces that produces the iconic “myst” effect. If it fails, mist production can be hampered, or stopped altogether. Transducer problems are one of the most common issues users face when the Opti-myst flame effect isn’t working.

A faulty transducer often attempts to draw too much current, causing the main printed circuit board (PCB) to trip and turn off the unit, this would usually happen at the point the transducer is triggered, around ten seconds after the flame effect is turned on.

Quick Tip: Check the bottom of the transducer and look for “M011B”, if this lettering isn’t on the bottom, you must have a non-genuine part, which are prone to causing issues with the PCB.


Opti-myst Fan: To create the flame effect, the mist must rise through the log bed, with a faulty fan the mist will sit in the sump, with little to no mist visible from the outside. If your fan isn’t functioning, it is easy to mistake the issue with a faulty transducer. It is simple to check the fan, we would suggest that you do it by taking it out of its housing and seeing if it rotates when the fireplace is powered on.


Main Printed Circuit Board (PCB): Main PCB failures can lead to a number of components losing voltage, resulting in specific components, such as the fan or transducer from working. Without tools like a multimeter, PCB faults are usually more difficult to troubleshoot. Using non-genuine Dimplex parts can also result in PCB issues.

Genuine Dimplex Transducer

Genuine Dimplex Glass Disk Transducer
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Dimplex Opti-myst Fan Motor SP03/23836/0

Genuine Dimplex Opti-myst Fan
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Dimplex Main Printed Circuit Board PCB

Genuine Dimplex Main Printed Circuit Board
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Excessive Myst Production

Some users may experience too much mist rising, even on the lowest setting, which can degrade the realistic flame effect in the Opti-myst electric fireplaces.

Untitled design 1

Non-genuine Fan: These days, it seems like there are more and more of them around, and they can be pretty convincing. Using one can lead to an excessive amount of mist rising through the logs.

Non-genuine Dimplex fans typically can be identified by a longer lead, and wider blades, another giveaway is the smaller sticker on the side. Verify the authenticity of the fan and replace it if necessary.


Main Printed Circuit Board (PCB): If your main PCB is faulty, it can also contribute to excessive mist production. Check the PCB for signs of damage or burning and replace it with a genuine part if needed.


Potentiometer: A faulty potentiometer can cause the mist effect to appear out of control. Test the potentiometer’s resistance range will go to 0Ω’s using a multimeter and replace it if it fails to do so.

Dimplex Opti-myst Fan Motor SP03/23836/0

Genuine Dimplex Opti-myst Fan
Available for next-day delivery

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Dimplex Main Printed Circuit Board PCB

Genuine Dimplex Main Printed Circuit Board
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Dimplex Potentiometer and Lead Temp 1300mm

Genuine Dimplex Potentiometer
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Flame Effect Lights Not Functioning

The following could be the cause of the problem if the lights aren’t illuminating but the “myst” effect is still functioning as usual:

Halogen Bulb (Halogen Bulb Versions Only): If one or more halogen bulbs have blown, they will need to be replaced. Check each bulb individually for signs of damage or burnout.


Lamp Holder (Halogen Bulb Versions Only): Faulty lamp holders can also prevent halogen bulbs from functioning properly. Please look over the sockets for damage or corrosion, and replace the lamp holder if needed.


Halogen Power Supply (Halogen Bulb Versions Only): If the flame effect is turned on but none of the halogen bulbs light up, there might be a problem with the halogen power supply. It is best to use a multimeter to test this.


LED Board (LED Versions Only): LED board failures in the newer Opti-myst models can make the lights appear dim, flicker, or not work at all. If you experience any of these symptoms, the LED board is likely faulty and will need replacing.

Dimplex Optimyst Bulbs

Genuine Dimplex Opti-myst Bulbs
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Dimplex Ceramic Lamp Holder Assembly

Genuine Dimplex Lamp Holder
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Dimplex 12V Halogen Power Supply

Genuine Dimplex Halogen Power Supply
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Genuine Dimplex LED Board

Genuine Dimplex LED 5x Board
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Preventative Maintenance

Extending the life of your Opti-myst fireplace through proper maintenance is easy, here’s some expert tips that will help.

Use Filtered Tap Water: It’s advisable to use filtered tap water specifically with the Dimplex Opti-myst range. Unfiltered tap water may contain impurities or debris that could accumulate on the transducer, potentially affecting its efficiency.

Tip: Dimplex suggest against the use of de-ionised or distilled water.

Regular Cleaning: The buildup of limescale and debris is inevitable, it’s good practice to clean the components with warm water, to ensure the flame effect is performing at its best.

Tip: Don’t allow water to sit in the fireplace for longer than 2 weeks.

Want A Professionals Advice?

If you find that these troubleshooting steps do not resolve the issue you are facing, remember that we provide free technical support to assist you.

Additionally, we provide a repair service specifically tailored for Opti-myst electric fireplaces, where we have served over 1000 customers. We’ll handle the collection, repair, and delivery, ensuring minimal disruption and optimal performance of your fireplace. If you require further assistance, consult Dimplex technical support or contact our team.

4 thoughts on “Solving Dimplex Opti-Myst Problems: A Comprehensive Troubleshooting Guide

  1. Brian Gibb says:

    Hi I’ve replaced transducer then the fan. The fan is like for like with the original but it’s not working. I’ve got mist the fan is not turning.
    Thanks

    • electricspares says:

      Hi Brian,
      I would suggest first double-checking the wires coming from the fan, the non-genuine fans look extremely similar, the red wire should go to the square side of the connector and the black wire into the circle side, this is a common issue with the non-genuine fans that can cause them not to work.

      If the fan isn’t at fault, and you’re getting mist, it must be an issue with the PCB, as the transducer and fan both run off of 24V.

  2. Ken marsh says:

    I bought one from eBay and has you said, wire’s are the wrong way round,so took your advice and switched them around and now fine so thanks for your help, better off paying extra and getting the genuine one,a lesson there,

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