Dimplex DuoHeat Radiators - how do you find them?

Jarcher1980

Hello. I'm wondering if anyone has any experience of these radiators from Dimplex. Although it has taken a while, I understand the workings of the radiator but would like to know about heat retention.

How long does the stored heat last? Is the house still warm, say, after six o'clock? How do people find them generally?

Many thanks in advance.

Gavin

grahamc2003

No experience, but I do have a bunch of storage heaters.

Since no one else with experience of them has replied, I'll have a go. Without going into details, I had a quick look at the heaters you are asking about, and for a great many reasons I would say avoid them like the plague, they have the potential to cost you a fortune and I really can't see any benefits of them. If anyone tells you these are cheap to run, then I'm afraid they are lying.

Jarcher1980

Thought I'd reply to my own thread and help anyone interested in Duoheat radiators from Dimplex. I could find very little customer feedback before we bought them, so i hope I can help someone with this feedback.

A few days ago, we had two Dimplex Duoheat storage heaters fitted to our small 1 bedroom house. We were dubious as to how effective they would be and how much heat would be retained for the evening.

After two days of testing, the stored heat lasts well into the late evening (about 9 o'clock) and then the peak panel is required to top up if needed. During this panel boost time, the heat feels the same as before. I've been impressed by the overall warmth. The house hasn't been roasting in the morning, and the heat output feels well regulated by the radiator (unlike the 1980s boxes I had in an old flat).

We have set up the bedroom radiator to take a half charge and the living room a three quarters charge.

I'm only concerned about potential electric bills with two storage heaters charging. We are timing washing/drying for off peak hours.

Any comments/advice? Anyone else with Duoheat experience?

Gavin

Garz

Are you on a multi-rate tariff with your supplier?

Cardew

Given they work off stored heat from the 7 hour off-peak period and 'normal' heat from the 17 hour daytime tariff, how do you know how much heat they are using from the latter tariff?

This link gives the operating instructions http://www.dimplex.co.uk/assets/kb/operating_instructions/DuoHeat_i_Range_Operating_Issue_7.pdf

However it is unclear to me how you determine when the stored heat has run out and you are using the 'expensive stuff'!

This quote indicates that it supplements the stored heat with expensive heat during the day:

Some
energy is taken in by the radiator when electricity tariffs are low and this is supplemented whenever needed by top up heat from a radiant

front panel, to ensure room temperatures remain to your preferred level throughout the day.

Jarcher1980

We're on normal E7 with NPower. I don't think they do E10 in Yorkshire.

Jarcher1980

Cardew wrote: »

Given they work off stored heat from the 7 hour off-peak period and 'normal' heat from the 17 hour daytime tariff, how do you know how much heat they are using from the latter tariff?

I don't know for sure when it starts to use electricity from the peak period. However, before we had the E7 cables connected we were still able to use the panel heater and I noticed that the heat originated from the bottom of the radiator (bottom of the panel). With the off peak now connected, the stored heat is clearly felt at the top of the radiator.

With this knowledge, I have been able to detect the panel coming on around 9 o'clock. There is still heat coming from the stored bricks though.

Although the above is purely circumstantial, I would conclude that the panel electricity is only being used for one or two hours. We then turn the settings down to 'frost protection' when we go to bed. I detect then that the panel has gone off.

The panel is only rated 0.5kwh as well. The upstairs panel is only 0.45kwh. So, the peak electricity shouldn't be costing the earth. We hope so anyway.

Hope this helps in some way.

Andy_WSM

Jarcher1980 wrote: »

So, the peak electricity shouldn't be costing the earth. We hope so anyway.

Just a thought...If you are regularly running out of heat at 9pm, then surely it would be cheaper to nudge up the input a little to take advantage of the cheaper overnight charge? i.e. you are using the heat anyway, so why pay premium price when you could store the heat from the previous night for a third of the price?

grahamc2003

Jarcher1980 wrote: »

I don't know for sure when it starts to use electricity from the peak period.
.....

The panel is only rated 0.5kwh as well. The upstairs panel is only 0.45kwh. So, the peak electricity shouldn't be costing the earth. We hope so anyway.

Hope this helps in some way.

I think it's critical to know when you are using peak rate. I would consider getting a plug-in meter, and plug in the day-rate heating line into that, so you can see exactly how much one heater is using at peak rates.

The 400w power does seem low - and would add heat very slowly to your room, leading me to think that it must be on for quite a few hours to make much of a difference. As Andy said above, I'd try to arrange it to store the max amount of night energy as possible, to avoid using the day rate top-up, even if only 400w (the price can add up, even for 400w per heater at day rates e.g. 10 hours for 3 heaters would add something like £35 per month to your electricity bill (of course, it could be supplementing 24 hours per day, or zero, seems to be a bit of an unknown). The cost for the same amount of heat from gas woold be around £12 per month for instance.

This is certainly less expensive than I initially thought, but then again it's only due to the day rate heating supplying a very small amount of heat. A good rule is never to use daytime rates for electric heating, unless you're prepared to pay a lot for the privilidge.

mockendo

@Jarcher1980: I'm currently thinking about installing the Duoheat (to replace old 1980s manual dial versions) and really interested to hear your experience - having trawled the web there doesn't seem to be much info from people actually using the system! A few questions:
- How is the input charge set on the storage element? The blurb suggests there's a room thermostat (on the heaters?) that automates this, but you mention setting the storage charge to 1/2 or 3/4. Is it controlled by the '4-zone controller' or do you have to go round each radiator setting them individually?
- Do you find the rooms extra hot in the morning, after the night-time charge of the storage heater element, then cooling through the day?
- How accurate is the room thermostat? Is it the Dimplex one? Do you need to play around with it much, or is it a set-and-forget type?
- Is it possible (asuming the Dimplex controller) to change the target room temperature for different times of the day? eg. 18oC overnight, 20oC from 7am-8am, 18oC during the day, 20oC from 6pm-11pm?
- Is there any option on the controller to monitor the electicity usage?

Many thanks!
Mark