Storage heater Saga!

[Stinsy]

I wanted a storage heater for my garden office "shed". I benefit from the Octopus Go Faster 5p 2030-0030 tariff so I felt I needed one of the new HHR (High Heat Retention) models fo two reasons: 1) I'm heating it only for 4hrs, and 2) I need the heat to stay in from half-past-midnight until the next afternoon. I know a lot of contributors to this forum use a solar diverter to charge their storage heaters with excess PV, I plan on doing the same at some point if I can find evidence that I generate spare electricity on days when I need heat.

So I ordered a Dimplex Quantum. Very expensive it was too. I looked at 2nd hand storage heaters but I couldn't find one close enough, that was "HHR", that fitted the space available, and was in good cosmetic condition.

And then the problems began! Unknown to me it has a "charging algorithm". Now call me a sceptic, but I'm always very wary of so-called "intelligent algorithms". Firstly the algorithm isn't "intelligent" it just does as it was programmed to do. Secondly the people who program such algorithms are never as bright as they think they are!

It has taken a huge amount of time and lots of telephone calls to Dimplex to understand how this algorithm is programmed and why it wasn't working for me. The telephone support staff are extremely courteous but not very well informed about their own product. They where utterly bewildered about the concept of a ToU tariff other than old-school 1970s Economy-7. My simple "Go Faster" tariff confused them, talk of solar diverters or how their products might work with "Agile" made me feel like someone from another planet!

Here is what I have learned:

The algorithm takes the room temperature at midnight. It then looks at the scheduled target temperature for the next day and works out how much heat it'll need and thus decides how long to charge for.

Here is why it doesn't work:

• If the room the storage heater is in is warm at midnight it won't charge.

• In my case it takes the temperature at midnight charges for 30 mins then cuts off because my cheap period has ended. At 2030 the heater is in "frost protect" for the rest of the day so it won't charge.

• There is no way to switch off or override the charging algorithm.

So basically I'm left with being forced to re-wire the thing

[Mr Gus]

Send it back under the "Not fit for purpose" principal with a letter to the MD.

The phrase is more widely known than the definition (but it often gets the point across)
https://www.wrighthassall.co.uk/knowled ... -liability

If it's been more than 30 days due to staff knowledge (lack thereof) then thats really their problem, you asked for a solution / explanation to work around if humanly possible & it sounds as if rather then giving you a straight answer that was delayed whilst it was kicked around at head office.

Dimplex have lost the lead for quality they were known for multiple decades back.

[Bugtownboy]

That appears quite a short sighted approach to the product design - a limited algorithm, effectively giving no user defined options.

Probably work for a lot of people, but times, and users, are changing rapidly. Surely their product should have this in mind ?

Was interested in how you got on, Stinsy. Looks like you’ve paid the usual price of the early adopter.

[Joeboy]

Unlucky to say the least. I run mine on Hive smart plugs. Send it back. If your cabin is in range of your home network then a dumb storage heater and smart plug are your friends.

[Mr Gus]

ditto, there are (not often marked for maximum load) but 3000 watt capable if you wish to try it.
Several I bought a few years ago are ok for oil heaters & the like.

Personally i'd try & find either a costco deal for a Delonghi dragon mk3 / 2 (led display versions) they have a fast heat up, not what you wish to really do, but,.

[nowty]

Sounds like the unit wont allow a cheap rate to start before midnight ?, cos Dimplex are only thinking E7 technology ?

Try changing the clock so that midnight on the heater aligns with 20:00 or in other words, make it think that the time is actually Real Time plus 4 hours.

Then set the charge period on the heater for 00:30 to 04:30 so that is charges in Real Time from 20:30 to 00:30 to align with your cheap rate period.

[Stinsy]

Send it back under the "Not fit for purpose" principal with a letter to the MD.

The phrase is more widely known than the definition (but it often gets the point across)
https://www.wrighthassall.co.uk/knowled ... -liability

If it's been more than 30 days due to staff knowledge (lack thereof) then thats really their problem, you asked for a solution / explanation to work around if humanly possible & it sounds as if rather then giving you a straight answer that was delayed whilst it was kicked around at head office.

Dimplex have lost the lead for quality they were known for multiple decades back.

I am very hesitant to send it back. I agree the heater isn't fit for purpose. The 30-day rule is very flexible, there is precedent for xmas presents that are bought months before and only inspected after they are opened, for example. A heater that isn't used until cold weather comes would be a clear case where the 30-day rule doesn't apply. However it was an absolute pain carrying the heater and bricks to the office and setting it all up. The thought of dismantling it all to send back doesn't make me very happy.

The stupid not-fit-for-purpose charging algorithm isn't the main problem. I'm sure it works well for some customers. It is the arrogance with which the product is designed to work only in one set of circumstances with absolutely zero regard for the real world being a varied and dynamic place. How difficult would it be to have the "intelligent" algorithm capable of being turned off?

Unlucky to say the least. I run mine on Hive smart plugs. Send it back. If your cabin is in range of your home network then a dumb storage heater and smart plug are your friends.

The "shed" is really a garden office. As such it has a gigabit wired network connection and it's own wifi access point. I wired the 24/7 connection to a FCU and the ToU connection to a socket with smart plug. I use TP-link smart plugs and fitted one that measures electricity consumption. The way it displays the data is pretty terrible but it has been good enough for me to see what the heater is (or isn't doing).

ditto, there are (not often marked for maximum load) but 3000 watt capable if you wish to try it.
Several I bought a few years ago are ok for oil heaters & the like.

Personally i'd try & find either a costco deal for a Delonghi dragon mk3 / 2 (led display versions) they have a fast heat up, not what you wish to really do, but,.

The smart plugs I have are 13A rated (lots are only 10A) my storage heater is only 950W (c. 4A) so no worries there. You need a lot of overhead in this sort of application. Storage heaters draw full power for the entirety of their duty cycle, even a 3kW fan heater would come on and off with a thermostat running for 5 mins in every 15 in a typical application.

It really does have to be a storage heater. and a "HHR" one at that, I need the heat to be retained from 0030 to 1800. The Dimplex Quantum claims to hold heat for 48hrs.

Sounds like the unit wont allow a cheap rate to start before midnight ?, cos Dimplex are only thinking E7 technology ?

Try changing the clock so that midnight on the heater aligns with 20:00 or in other words, make it think that the time is actually Real Time plus 4 hours.

Then set the charge period on the heater for 00:30 to 04:30 so that is charges in Real Time from 20:30 to 00:30 to align with your cheap rate period.

Basically Dimplex think the only ToU tariff is Economy-7. They have hobbled their product so that it cannot function in any other situation.

I had thought of doing as you suggest and changing the clock. The problem is the office is sometimes in use in the evening, even if that is 7 or 730pm and therefore would still be warm when the heater takes its "midnight" reading at 8pm.

The next step is to open it up again and see how the circuit is arranged. Maybe I can wire a relay to be permanently closed, or can wire power directly to the heating elements? I'm keen to ensure the over-temperature protection be retained though!

[Stinsy]

UPDATE: I've found a circuit diagram! The over-temp sensors are separate from the PCB and inline with the power cables so I don't lose them if I disconnect the heating elements form the PCB and connect them to the off-peak supply.

[nowty]

UPDATE: I've found a circuit diagram! The over-temp sensors are separate from the PCB and inline with the power cables so I don't lose them if I disconnect the heating elements form the PCB and connect them to the off-peak supply.

Excellent, that means you can run the booster element as well in your 4 hour slot for that little bit extra and have a manual or timed switch for running the fan.

I feel a dastardly project coming on here and we like pictures.

[Stinsy]

UPDATE: I've found a circuit diagram! The over-temp sensors are separate from the PCB and inline with the power cables so I don't lose them if I disconnect the heating elements form the PCB and connect them to the off-peak supply.

Excellent, that means you can run the booster element as well in your 4 hour slot for that little bit extra and have a manual or timed switch for running the fan.

I feel a dastardly project coming on here and we like pictures.

I was on the same page! My memory isn't what it was but it is possible that I'll be able to just shift a few spade connectors about to achieve my aims.

Will see if I can find time this evening...