Dimplex Opti-Myst fires

[Lilly7874]

Hi I have Dimplex GOS20 Electric Fire only used the actual heater on it twice, last night the heater decided to switch off, thought it had switched off due to the thermostat control on it, tried the heater again this morning and still not working, any ideas what it could be or what I need to replace,just ran out of guarantee last month thanks

 

[winston1]

just ran out of guarantee last month thanks

Is that the one year manufacturers guarantee? If so that is in addition to your legal rights under the Consumer Rights Act which gives you 6 years protection in England and 5 in Scotland.

 

[Pitch182]

Just for info, I installed some 20w amber mr16 lamps along with 2 x 2w amber led lamps. There is still enough heat to cause convection enabling the mist to rise. Power consumption is down from 180w to 44w. Must less heat produced around the lamp holders which has got to be a good thing.

 

[Sagaris1987]

This thread has been really helpful but unfortunately all the tips haven't helped me fix my issue.

I have a opti-myst stove. Problem is when I switch it on the lights come on, then after 30 seconds the mist kicks in but then immediately cuts out and the lights switch off too. I've recorded a video here if it helps

You can hear the click at 30 seconds, see the water starts bubbling, mist starts and then it beeps and cuts out.

I've replaced the transducer but it hasn't helped. The mist fan doesn't start spinning at any stage.

Any ideas? Not sure what to try next. Could the fan have gone and cause this or a bad connection somewhere maybe?

 

[SithLordHood]

I thought i would share my experience:

Purchased a Opti-Myst fireplace back in Dec 2019.
Ran for a week or two, noticed the bulbs (and the water tank) get very hot during use!
After reading somewhere (may have been on here) they suggested changing the 50W halogen bulbs for 30(35?) watt bulbs to prolong the life of the tank and reduce energy consumption.
Decided to chance it and I ordered 20W bulbs instead.

These have worked flawlessly for the past year, not had any issues with the fire whatsoever.
Used the fire quite a bit (only the flame effect mainly) and have cleaned it maybe three or four times in the last year, nothing major, just removing the white deposits from the plastic and cleaned the sump. My wife has a habit of leaving the fire on and it tripping itself off once the water has ran out.

Using 20W bulbs does mean it takes a little longer for the flame effect to get going, but in my opinion it still looks fine, if this is the reason i am not having any issues then it's certainly worth the compromise.

I'm finding the bulbs hard to come by though.. have managed to secure 4 off ebay, the previous supplier only seems to stock the 50W nowadays..
The ones i use are 'Prolite Amber 12 Volt Halogen Dichroic MR16 20 Watt'

https://www.easy-lightbulbs.com/light-bulbs/coloured-bulbs/halogen-reflectors/2-pin/m252-a-ca/?gclid=EAIaIQobChMIi5rs3dXw7QIVw7TtCh3lQALIEAQYASABEgIu0vD_BwE

 

[SoftTopGeek]

We have an Opty Mist, the Albany, since 2013.
In December 2020, I searched for help with it, and found this site and thread. Wow!
Having had the (what now seems like typical) problems, I thought I'd say what I have found:
The heater always works fine (although not often used), so no issues.
The LED log effect always works fine, no issues.
The uplights work ok, now that I have replaced many of the lamps, and replaced all of the lamp holders. (They get really hot, so needed to replace the holders, and used the ceramic type).
At some point, the magnetic switch stopped working, meaning that the water level in the sump wasn't detected, and the lamps and mist maker would never try to run. I changed this switch, with one bought from CPC, and then that part was ok.
The little fan stopped at some point, and I discovered that this wasn't getting any power. I derived a DC supply from the AC supply for the lamps, along with a speed adjuster, and that all seems fine now.
The big issue, was the mist effect.
This worked great for the first few years, but then started to get progressively less consistent. Often wouldn't start properly, and then eventually even after an hour, would hardly do anything.
We worked out that the sump would sometimes overfill, and that played havoc too. This was due to a tiny hole in the blue water tank, which I smothered in airfix glue to seal up. (Air was getting into the tank, so letting water out when the sump was already full).
After trying all the tips with the must issue, (clean the disk, descale) our conclusion was that we needed to replace the transducer assembly. We bought it (very easily) from Mouser electronics.
The mist maker, is a TDK module (circuit board and transducer).
I googled NB-80E-01-H, and the Mouser catalogue number came up from there.
It turned into a really easy fix, just taking out the old transducer and its control board from under the base of the sump, and fitting the new on in. I put a dab of silicone grease on the rubber o ring when fitting it back together, to reduce the chance of water passing by it.
This was done on Cristmas eve 2020, and used everyday since, and each time has been fine.
One of those fixes where you think - should have done that ages ago!!! We live and learn.
Hope this helps someone with similar issues.

 

[Aworth]

Hi hope someone can help me. I have had my opti mist fire - DimplexCadogan CGN20 for about 9 years. It was working fine. But then I noticed the mist/smoke stopped working and fire started cutting out. When I checked the water was filling up where the transducer discs are in the sump which is why it was cutting out I think. Further investigation I noticed the fan isnt working either but not sure if I need to replace the transducer discs or the fan? Is there anyway to know which is the problem or should I change both? The bulbs still light up and fire still turns on if I don't have the water in there
Can anyone help? Thanks

 

[mdp1673]

Hello

I’ve got the Piermont PMN 20 model and as everyone else on here it’s stopped misting. The transducer disc is knackered (pitted, black and flaking bits off) and the new disc types don’t work and for the life of me I can’t find anything similar.
I’ve tried to get a replacement sump but they are out of stock everywhere.
I have found this though https://www.mouser.co.uk/ProductDetail/TDK/NB-80E-01-H/?qs=4WjKNJoURz6KzK6vce58/w== which looks like it’s a replacement for the circuit board and transducer disk.
Has anyone tried swapping this out - is it compatible?
Ta

 

[mdp1673]

And it turned up, 5 minutes to fix and it’s working a treat.

 

[SoftTopGeek]

Hello

I’ve got the Piermont PMN 20 model and as everyone else on here it’s stopped misting. The transducer disc is knackered (pitted, black and flaking bits off) and the new disc types don’t work and for the life of me I can’t find anything similar.
I’ve tried to get a replacement sump but they are out of stock everywhere.
I have found this though https://www.mouser.co.uk/ProductDetail/TDK/NB-80E-01-H/?qs=4WjKNJoURz6KzK6vce58/w== which looks like it’s a replacement for the circuit board and transducer disk.
Has anyone tried swapping this out - is it compatible?
Ta

That is the module that I purchased for ours, and it has worked fine since. Hope yours does too.

 

[mbldn]

Hi guys, I bought a Dimplex Verdi:
the mist and heat work fine, but the lights don't turn on at all. I received a new lamp base and transformer via warranty.
I only managed to replace the lamp base (no change), but have no idea where the transformer goes?? Does anybody know how to open this thing?

 

[Martlea]

I've had my Dimplex optimyst blk heater since around 2012. The main issue I had just after warranty expired was corrosion of lamp holders. A new assembly cost an extortionate £80 and suffered same defect after a while. So like others I sourced ceramic holders for a few £'s and no now fit my own replacements from time to time. Also like others the myst effect is weakening now and so I face eithe trashing the fire or sourcing a viable new transducer to keep it a while longer.
I am inclined to just scrap the thing and find a quality alternative particularly now new legislation may soon prohibit the sale of the colour halogen lamps needed for fire colour and the heat convection of the myst effect.
Any suggestions for a reasonably priced log or coal effect replacement for this model?

 

[Andy-glide]

I have a CGN20 stove type Opti-myst which has now stopped working. About 2 weeks ago it started to emit a strange smell, something like damp clothes or a swimming pool not what I would say was a burnt component type smell. Any way I cleaned the sump and this seemed to reduce the smell and the fire worked fine. Then the halogen lamps became intermittent sometimes they would all start when the fire was turned on but on other occasions nothing came on. Now the fault with the lamps is permanent and nothing happens when the fire is powered.
Tried cleaning the ultrasonic transducer but the failure mode is the same. Tested the water level sensor and that works fine with the fire beeping when the water level is low.
Have ordered a replacement transducer but unclear is this is the issue as unsure if there is any feedback to the main control board that the sump unit is working or not.
Yet to look at the lamp connections but cant believe all the holders have failed together but will investigate further.
Interested to know if others can point me in a more likely direction as to the cause of the fault.

 

[Andy-glide]

Well after several false starts thinking it was a lower sump fault had a poke around the main control board although nothing stood out as the fault. Then decided to isolate the output side of the transformer to check that it was not a short on the output and to my surprise the entire wire came free when I removed it from the connector block.

Having removed the entire back of the fire you will find a standard plastic connector block one side of which was completely destroyed. Replacing the wire and the connector restored the lamp supply but after approx 2 mins the fire again shut down. Suspected this was the sump not starting the ultrasonic disc, so did some more impedance checking on the ceramic disc. Found I had incorrectly assembled it after I had removed it from the rubber seal which resulted in a short on the device.

To correctly assemble the item it is necessary to de-solder the screen can, remove the outer metal connector ring and then mate it with disc so that it makes contact with the two parts held together by the internal recess of the rubber O ring. Not an easy item to assemble!

Fire now fully works resulting in a massive saving as was minutes away from ordering a new one.

PS Dont bother phoning Dimplex at the moment as they are not offering repairs on fires which are out of warranty.

 

[G4FAQ]

I thought i would share my experience:

Purchased a Opti-Myst fireplace back in Dec 2019.
Ran for a week or two, noticed the bulbs (and the water tank) get very hot during use!
After reading somewhere (may have been on here) they suggested changing the 50W halogen bulbs for 30(35?) watt bulbs to prolong the life of the tank and reduce energy consumption.
Decided to chance it and I ordered 20W bulbs instead.

These have worked flawlessly for the past year, not had any issues with the fire whatsoever.
Used the fire quite a bit (only the flame effect mainly) and have cleaned it maybe three or four times in the last year, nothing major, just removing the white deposits from the plastic and cleaned the sump. My wife has a habit of leaving the fire on and it tripping itself off once the water has ran out.

Using 20W bulbs does mean it takes a little longer for the flame effect to get going, but in my opinion it still looks fine, if this is the reason i am not having any issues then it's certainly worth the compromise.

I'm finding the bulbs hard to come by though.. have managed to secure 4 off ebay, the previous supplier only seems to stock the 50W nowadays..
The ones i use are 'Prolite Amber 12 Volt Halogen Dichroic MR16 20 Watt'
...

I make my own amber effect lamps using Energizer 16 watt (20 Watt) clear lamps available off ebay at the time of posting £6.85 for 5 lamps post free, get a pot of Pebeo vitrea 160 glass paint Saffron Yellow about £6 off amazon (enough paint in the pot for dozens of lamps i would guess), paint a thin coat on front of lamp with a brush or sponge. It does say to bake in an oven for 30mins at 160c but if you fit the lamp back into the fire and power up you wont need to, it will bake on itself after a while. The lamps are also available in28 watt (35w) if more light is required.
All these halogen lamps will eventually be hard to come by as halogen is now being phased out with fluorescent lamps to follow. We should be ok while stocks last !
Photo is my Gosford fire with the 4 lamps having been replaced. Saving some electric too 4x 16watt = 64 watts versus 4x 50watt (original lamps) = 200watts !