problem with Dimplex Duo300n heaters

[Agaxyz]

Hello, I’m not an electrician and I have a question in relation to Dimplex Duo300n.

Some background information: a couple of months ago I have moved into the property where those heaters are in place (there is 5 of them).

The people who used to live in this apartment before, used RXPW4 control panel for majority of them (they also said all heaters were working). It was end of summer when I moved in, so I switched off this central RXPW4 control panel as I did not need that much heat during the day and planned on only using the heat from the night storage.

• One of the heaters, seems not to be previously connected to this main control panel plus it has been on all the time (even at the end of the summer) for the night storage only and it works perfectly – this heater just an example how those heaters can work.
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• The 2nd heater once I turned it on by turning all 3 switches on on the wall, had a constant buzzing noise. Well, I was told by the previous tenants that sometimes the heaters might give clicking, buzzing noises when turned on but I did not assume it might be for that long, as once I turned on that one and it was buzzing for 30 min, at the end I turned off as it must be simply broken. I do not know if it would store the heat overnight because I’m not going to leave it on with that buzzing noise for the whole night. Having said that, I did run the diagnostic on it (the link will be below) and somehow the result came as the 2nd bar from the top flashing so it should not have a problem? But this constant buzzing?

However, the most important question I have is in relation to 3 other heaters – they do not seem to store the heat overnight (even though I would set the overnight storage temperature to max or one bar below max) though they would “work” on the day tariff. The description on how they actually work is below:

• The 3rd heater, once turned on (what I mean by that is turning on all 3 switches on the wall) is slightly buzzing for a couple of seconds. Next the noise stops. Again does not store the heat overnight. For the day heating, it starts to heat when there are 8 read bars on the heater day control panel. However, it stops heating on its own after about 10 -20 minutes, even though the temperature in the room is less than 21C. It seems to heat constantly when all 9 indicators are red. So it does not heat when there is anything between 1 to 7 red bars on the control system. The heating it provides when on level 9 is not as strong as the heating provided by heater no 3 (described below).
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• The 4th heater once turned on is quiet so this is ok. Again it does not store the heat overnight either. For the day heating, it starts to heat when there are 3 read bars on the heater control panel. However, it stops heating on its own after about 20 minutes, even though the temperature in the room is less than 21C. When I increase the heat control to 4 red bars it also heats up only for about 20 min and turns itself off. It seems to be heating constantly when there are 5 red bars on the control panel for the day heating.
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• The 5th heater, once turned on is also quiet so this is ok. Again, it does not store the heat overnight. For the day heating, it starts to heat when there are 3 read bars on the heater control panel. However, it stops heating on its own after about 50 minutes, even though the temperature in the room is less than 21C. When I increase the heat control to 4 red bars, it seems to work constantly and provides better/warmer heat at this level 4 than heater no 1 at level 9.

What I did so far to try to sort this out is below plus my questions as well:

• I found the video how to run the diagnostic, the link is here
  , did it for all 4 heaters and all the them had the 2nd bar from the top flashing so they seem to pass, all is fine somehow? Why would they not store the heat overnight than?
• I turned all 3 heaters (= heater no 3,4,5) off for the couple of hours and back on – no change, still do not store heat overnight
• I turned all 3 heaters off for about 10 second and back on – no change, still do not heat overnight
• Shall I try to turn them off and on almost immediately? Maybe this somehow will “kick start them?”
• I thought that maybe I should set up this RXPW4 control panel so the heat comes during the night (not as a background/night system, but maybe somehow on the day system will turn itself on during the night though it will be at a night rate so still cheaper?), in that case I could heat up the flat at night. However, once I waited deep into the night when the night electrical tariff comes on and turn on a couple of bars for the day tariff on each of 3 heaters – nothing happened, they stayed cold (not surprise here as it was night not day, but it was just an idea worth trying…)

As mentioned, the previous tenants told me that all heaters worked well when they lived here. It does seem a bit odd that 3 of them suddenly stopped working properly by not even storing the heat overnight….

I was also told that it might sound like the room temperature has a fault however Dimplex Heater no longer making parts for this heater (those heaters were discontinued). Additionally, I was told that there might a loose connection or they might need a heater full replacement (I cannot afford this).

Would anybody have any better idea what the problem/s might be for each of those heaters? What might help, what I might still try to do? Would calling an electrician to look at in person help if there are not parts for those heaters?

Thank you very, very much for reading this whole story. Hopefully there will a solution to all of this.

 

[Agaxyz]

Sorry I haven't replied for a while.
Thank you for the pics, which indicate there is nothing untoward with the power arrangements.

I'm afraid, basically, I know nothing about the controller!
If you decided to try it, I would recommend setting the clock to the correct time.
But I'm inclined to believe the background heating should work with the controller switched off - something you might check with neighbours if you haven't already. If that is the case, I would leave the controller 'off'.

So it seems there's no explanation for heaters not working, other than some failure(s) inside.

As far a water heating is concerned, it seems the main heater is directly on the night rate supply, and although there is the RXPWIF switch there, it's not actively timing the water heater. That's not a problem.

So I fear I don't have any other suggestions. It sems each non-working heater needs to be opened up and fault finding carried out.
The problem here is that an engineer's call-out charge, hourly rate, and the likely cost of spares (and finding them), it likely to be considerable. For this reason you may find you will only be able to get quotes for replacing the heaters, as many may consider the 'repair' option is so unpredictable, they won't want to risk losing money!
This is where a DIY repair (by someone competent) is probably the only economically viable option!

Hello again, I have contacted the electrician to come and have the look at those heaters, finally he might come and before the visit the sent me the message - part of the message is below:

"...On my visit as well as discussing the work you require I will also need to look at the existing fuse board. Two other things again we need to check is your water and gas (or oil) bonding. With them being metallic pipes rising from the ground these can carry an earth potential, we need to ensure they have the necessary earthing cables and clamps and run back to the Main Earthing Terminal, again this should be at the fuse board. Sometimes it is not always possible to confirm these 100% of the time but will give us a good idea of what's going on. With the need of having to look at these items (Fuse Board, Water & Gas) it would be good if anything stored in the same cupboards as them were removed so we can get the best view possible...."

I understand the fuse board needs to be checked but the water and gas pipes ( I do not have gas anyway)? Ok I'm not an electrician so is it a standard thing? The electrician wants to come have a look, assess first and next will give me a quote. I thought that when he comes he at once would be able to at least check and if necessary replace the fuses but the switches next to each heater, it seems like a small job (if that needs to be done). I also offered to buy some parts still available on ebay - you had suggested but have not beard about it. It would be more efficient if "simple" things which might casue the issue could be fixed at once, wouldn't it? I am just worried by this email that it already sounds like a huge job...

 

[Avo Mk8]

Hello again, I have contacted the electrician to come and have the look at those heaters, finally he might come and before the visit the sent me the message - part of the message is below:

"...On my visit as well as discussing the work you require I will also need to look at the existing fuse board. Two other things again we need to check is your water and gas (or oil) bonding. With them being metallic pipes rising from the ground these can carry an earth potential, we need to ensure they have the necessary earthing cables and clamps and run back to the Main Earthing Terminal, again this should be at the fuse board. Sometimes it is not always possible to confirm these 100% of the time but will give us a good idea of what's going on. With the need of having to look at these items (Fuse Board, Water & Gas) it would be good if anything stored in the same cupboards as them were removed so we can get the best view possible...."

I understand the fuse board needs to be checked but the water and gas pipes ( I do not have gas anyway)? Ok I'm not an electrician so is it a standard thing? The electrician wants to come have a look, assess first and next will give me a quote. I thought that when he comes he at once would be able to at least check and if necessary replace the fuses but the switches next to each heater, it seems like a small job (if that needs to be done). I also offered to buy some parts still available on ebay - you had suggested but have not beard about it. It would be more efficient if "simple" things which might casue the issue could be fixed at once, wouldn't it? I am just worried by this email that it already sounds like a huge job...

The electrician will need access to the fuseboard, so asking if things can be cleared out of the way is good. However it sounds to me as if the electrician is wanting to look at earth bonding arrangements in your electrical installation, which in my humble opinion is nothing to do with determining why your heaters don't work (and it will not give him "a good idea of what's going on" with regard to the heaters.! It looks suspiciously as if he is looking for further, perhaps more remunerative, work, or an excuse to conduct an Electrical Installation Condition Report (EICR). If yours is a rented property (sorry - can't remember!) the Landord is responsible for having that done, not you.
You might tactufully sugest he is welcome to review water pipe bonding if he must, but only after he has diagnosed, and fixed, your heaters.
I don't think it is a good idea to buy random spare parts in advance of an electrician looking for the fault.
Just be a bit wary and reiterate that you want a diagnosis of why the heaters do not work, not advice, or a report, on the condition of your electrical installation.

 

[AlexFullerton]

You might have to call an electrician for this so they can test the on peak and off peak flow for you.

 

[Agaxyz]

Hello,

A bit of an “update”.

A couple of months ago an electrician came to look at those heaters which did not store the heat overnight. It was one brave electrician who did not have much experience with those heaters but was willing to help, all other electricians to whom I had talked to, said it was not worth it to look at those heaters anymore as they were discontinued.

Ok, so the electrician took the heaters all apart to check. It seems the CREDA DIMPLEX STORAGE HEATER CHARGE CONTROL MODULEs were not working in them. So he also took apart that one heater that used to work properly, and from that working heater he took that control module out and put it in the other heaters (those which did not store the heat overnight) to check if it would be working there and if it would make a difference – I am not an electrician, so I cannot specifically say what he did, but he did connect some cables to check the day electricity flow, including the night electricity flow E7 and it seemed it was flowing/working (he was able to check this night E7 electricity flow somehow during the day when he was here - apologies I know my description of what he did is rather “not precise/not professional” yet again I do not know much about the electricity). Anyway, once he checked those other heaters with that control module from that heater which worked he decided that that control module would need to be changed in all of them…(=needed to be changed in those ones which did not store the heat overnight to make them store the heat overnight). Ok.

At the end of the visit, once everything was checked, he put all heaters back to how they were, it also means that he put back the control module which was working last winter into the heater that used to work last winter. It was summer, the heaters were turned off, so I could not check if it was working again as it used it, it was too hot outside as well. Now it is getting colder, I turned that heater that used to work on, but the night storage heat stopped working… I could not believe it….So it does not store the heat overnight = it is cold in the morning, so the background mode is not working (it does not store the heat overnight), but the comfort zone is working.

It seems to have the same problem like with the other heaters. But what happened? It used to work before, and the electrician put the correct control module back in? Could you please advise? Would you have any idea how to make at last this one heater work again? As far as I know/read about those heaters the explanations might be:

• already mentioned: the control module also stopped working (but is this possible that something like this could happen just because he took it out and put it back in)?
• perhaps it is bad connection as he was disconnecting and connecting the parts heater?
• perhaps it is the thermostat (it seemed a little brown when he opened the cover, as the heater was used a lot)?
• Is it possible that I should only need to change the fuse which is next to the “off peak” switch on the wall to make that heater that used to work, work again?
• Any other idea why this one heater is not storing the heat overnight either now? Plus, which of the 4 ideas I mentioned is the most probable?

Someone, earlier in this thread mentioned “….The fusible links for the background heater have blown …” I was looking on the internet for those fusible links but can not sure how they look?

I think what I would like is the list of parts I should buy so when I call this electrician he can check and replace at once what needs to be replaced. The winter is coming, and it would be necessary to have 1-2 of those heaters working… In advance thank you for any advice.

 

[Avo Mk8]

I've been looking at availability of parts, and it seems that's considerably worse now than it was a year ago. There have been no spares available from Dimplex for years as you may know. I could not see any of the spares you need on eBay now, and one charge controller I see that had been for sale in the past went for £150!
Some of the electronic components inside your heaters, such as electrolytic capacitors, have probably reached their end of life, and the reliability of the assemblies may be so impaired that repair of your heaters with secondhand parts may not last long. In fact I think your enterprising electrician has demonstrated that concept - that the remaining parts are now so fragile that they may fail!

I think you have to accept the fact that these heaters are beyond economic repair. Sorry.

 

[Agaxyz]

I think I might give it one more try. Seem a bit bizarre that those heaters are working in the other flats (not ideally and not all of them but still ...) and all of mine do not store the heat overnight ( plus the one which is constantly buzzing when turned on is totally out of order).. However, can someone please recommend some good heaters with the night storage option as well - just in case I really have to get one...

 

[freddo]

The general design and the PCBs in these are terrible and have a very short life. The components are underrated and the PCBs are mounted in a hot location, making the problem worse. They are often brown from the heat. They can sometimes be repaired but if the board is burned it's game over.

These are rubbish heaters, you are better off replacing them with the newer Quantum heaters, the design is much improved, though care should be taken to set the parameters up correctly to prevent excessive electricity use.

 

[Avo Mk8]

I think I might give it one more try. Seem a bit bizarre that those heaters are working in the other flats (not ideally and not all of them but still ...) and all of mine do not store the heat overnight ( plus the one which is constantly buzzing when turned on is totally out of order)..

You could always see if these people can repair the modules in your radiators, if you can get the offending items removed safely:

Module pcb REPAIR SERVICE Storage heater Dimplex Duoheat 300n 330 400 N 87389B | eBay

Any Storage Heater. Brief Fault Symptoms. This is a Repair Service. Test and repair of your module/pcb Update for orders placed after 25/08/22. What you need to do. In the unlikely event of loss, our liability is limited to the cost of the repair service.

www.ebay.co.uk

I have no experience of this seller, though they seem to have good feedback, but I'm not recommending this as the complete solution to your heating issues!

 

[Agaxyz]

Thank you for the suggestion

 

[Agaxyz]

Just a question, is it safe to take the module out and leave the heater without it for a week or so? - not sure how long the repairs will take.

 

[Avo Mk8]

Just a question, is it safe to take the module out and leave the heater without it for a week or so? - not sure how long the repairs will take.

You must isolate the heater, ie turn it off on the wall or fusebox before removing the module, and I suggest leaving the heater switched off while it's being repaired. No harm will come to it if you do that.
Disconnect the leads at the module, remembering where they go! Photo's are useful. Don't send leads with the module as (accidentally) you may not get them back!

 

[Agaxyz]

Ok, thank you very much

 

[Agaxyz]

One more question: on the top (inside) the heater Dimple duo300n there are those two small parts :

1. Over Temperature Cut-Out

2. Smarty & Manual Reset - it seems on some websites it is also called "limit thermostat"

Could someone please tell me if either of them is not working or both of them are not working, how would the heater perform in that situation (if at all)? For example if no 1 that is "Over Temperature Cut-Out" is broken but not 2 is ok would the heater not heat at all? And what happens when no 2 is not working (but no 1 seems to be ok), plus what happens when both no 1 and no2 are not working?

 

[Agaxyz]

Hello, I think I own everyone who read this whole story and/or provide support/advice the ending: I decided to fix all 5 pcb casue it seem none of those heaters was working correctly. First I sent 2 to be fixed, just to check, if they will be repairable at all and how they would work after the repair. Next I sent the other 3. When the electrician came it also appeared that in 2 heaters, the over temperature cut-out and limit thermostat parts were broken - they have been replaced with the "duo part". Four heaters work ok now, the 5 one works ok on the day rate but accumulates very little heat overnight. The pcbs after the repair have 1 year warranty which is great, plus one heater, once it accumulates the heat overrunning give so much heat during the day that is enough on most of the winter days. Fingers crossed all will be ok for the years to come. The end

 

[DPG]

Hello, I think I own everyone who read this whole story and/or provide support/advice the ending: I decided to fix all 5 pcb casue it seem none of those heaters was working correctly. First I sent 2 to be fixed, just to check, if they will be repairable at all and how they would work after the repair. Next I sent the other 3. When the electrician came it also appeared that in 2 heaters, the over temperature cut-out and limit thermostat parts were broken - they have been replaced with the "duo part". Four heaters work ok now, the 5 one works ok on the day rate but accumulates very little heat overnight. The pcbs after the repair have 1 year warranty which is great, plus one heater, once it accumulates the heat overrunning give so much heat during the day that is enough on most of the winter days. Fingers crossed all will be ok for the years to come. The end

Nice one, thanks for letting us know.