Dimplex Quantum QT070 f series - How is it different to the newer RF models and how do they work?

Slippernipper

I have a secondhand Dimplex Quantum QT070 f series storage heater that I would like to have installed in my flat.

Could anyone tell me what the difference is between this model and newer models with rf? I didn't actually realise there were different models when I bought it.

Could someone also explain how they would work with a time of use tariff instead of economy 7. Why can they not just be plugged in? They are such low wattage. If they were plugged in is there not a way to set the charging time on the display. I have read other threads on this but I don't really understand them.

And also, when they charge up, how is the heat contained and then released later? I understand the concept of heated bricks in an insulated box, but is there a flap that's closed when it's charging and then open when it's giving off heat? 

These may be really basic questions but i'm confused. I also can't find an online manual for this model.

Please help!

mmmmikey

Hi, I'm not sure but I think the RF models have smart features, that is they can be controlled using WiFi and/or a special control box. Again I'm not sure but I think that some of the older models only supported two wire installation, which I'll explain in a bit. But don't worry if that is the case because you can still use it.

Let's start with a standard two wire installation. In this case the heater has 2 supply cables. One cable is controlled by an Economy 7 (E7) electricity meter and only comes on at night during the cheap rate period. This is s used to heat up the bricks which are in a very well insulated box. This is called the restricted supply.

The second cable is always live which keeps the display and controls active. This supply also operates a fan as needed which is what forces the heat out. AFAIK there's no flap, the output is just controlled by the fan. There's also another "emergency" heating element which this second supply operates. This is only used if the bricks inside the insulated box become too cold to heat the room. This is called the unrestricted supply.

In a single wire installation, you only have an unrestricted supply, that is one that is on all the time. You heat the bricks up at the cheap rate time by setting a timer on the heater. This allows you to use the heater without a special meter and second restricted supply but has the downside that if you set it wrong you can end up using expensive day rate electricity to heat the bricks which can be mindful bogglingly expensive. Not a problem if you have your eye on the ball but it's a risk to be aware of.

If you have an older heater that doesn't have a single cable option but don't have a restricted supply controlled by the meter then you can still use it. In this case you would connect the restricted supply cable to an external supply timer, such as an immersion heater timer, and set the on times there to match the cheap times for your tariff.

The smaller heaters can sometimes be connected to a standard supply but it depends what else is on the same circuit and it's normally only practical to connect a single heater. To do this properly you need to replace the socket with a switched outlet. If you use a standard 13A plug at full whack for a prolonged period there is a risk of over heating and fire. Unless you are very familiar with domestic wiring connecting this in is a job that IMHO should be entrusted to an electrician. It's not that it's a particularly difficult DIY job but just that the implications of getting it wrong can he serious.

Hope this helps, Mike

Scot_39

Have wiring regs changed ?

Mines are wired directly back to 20A mcbs in the CU  for main charge input.  Including two small units that take c1.7kW - just c10%  above the current quantum 070 models.

(I didn't upgrade c2020 - but my quote from memory was going to reuse those feeds for non rf quantum series restricted inputs - adding new live spurs for fans / boost etc.)


And without a bs1363/EV stamped socket - wouldn't run 2kW plus for hours on end.  And iirc granny chargers those are presumably aimed at are themselves now lower nominal in uk iirc 10A / 2.3kW nominal max. 
 

Slippernipper

Thank you so much for taking the time to reply. 

help.gdhv.co.uk/support/solutions/articles/79000134079-where-can-i-find-an-instruction-manual-for-my-quantum-heater-

I've found the manuals above and i don't think the f series is set up for single supply. Could anyone confirm this? 

So is this correct... my model needs the restricted supply to heat the main elements. There's no way for me to control the charging times of the main elements without an external timer wired from the heater and into the mains?

When i've plugged in the heater to test it and i've put it on boost, the heat i am getting is from the secondary element only?

And am i right in thinking that once it's set up even the older models like mine, will calculate how much it will need to heat up on the restricted supply depending on what target temp i set, and how many hours I want to to give out heat ( which is actually just how many hours the fan is operating)? So i don't actually set the timer at the times i want it to charge... just the times it can charge if it decides to?

Gosh, it's very complicated for such archaic technology hahaha

I am in the processes of getting a quote from an electrician and will not be attempting any electrical work myself. I just want to understand it all so i know how it all works. 

mmmmikey

Hi again, although it sounds complicated when you try and write it down, when you actually come to use it it all becomes fairly easy. As far as heating the bricks during the cheap period is concerned, you have 2 options. You can either just set the timer to switch on and off for the full duration of the cheap period and let the heater work out how much to heat the bricks for. Or you can set it for a fixed amount of time (say 3 hours) which sets a maximum amount of heat to store which can help you manage your budget but means you may find the flat isn't as warm as you want it on colder days and you need extra heating, for example on your living room if you're watching TV. It's not actually too critical if you put a bit too much in as the insulation means much of the heat will be there for the next day if you don't use it all.

I'd suggest updating this post when you've got the heater installed and are ready to go. If you also post details of your tariff I'm confident we:ll be able to help you get it working as you want by suggesting some initial settings then helping you to fine tune them. I'm a bit of a storage heater anorak (your word @Gerry1 if you're reading this, which made me smile) so I can help you with the general process as I'm doing something similar with external timers. But my heaters are Elnur ones so I'm not familiar with the Quantum controls. There are plenty of folks with Quantum heaters here who I know will be happy to help if needed, though.

Slippernipper

That's very kind, thank you! I will definitely appreciate the help once installed.

Gerry1

Slippernipper said:

I have a secondhand Dimplex Quantum QT070 f series storage heater that I would like to have installed in my flat.

Are you sure it's a QT070?

Dandytf

Off topic, I'de now prefer one of the Wifi ready models for final Storage Heater upgrade in hall.
Must check heater size guide next year, prob 500 or 750w should suffice,Hall is straight narrow style.
Edited seems to be from 1000w similar to RF model in living room. 

OP
Dimplex. RF models have standalone separate  RF Module.
That's one plug for power and needs one Ethernet Cable to allow Comms to/from Heater.
These models or versions allow 24/7 timed heating schedule.

Not a concern via  QT070? -looks to be Non Wifi i.e. Controlled direct from IQ LCD Panel on Heater.

thanks

Gerry1

mmmmikey said:

I'm a bit of a storage heater anorak (your word @Gerry1 if you're reading this, which made me smile)

@mmmmikey It's a fairly standard term (well, at least among anoraks...). Probably originated among trainspotters spending many hours freezing at the ends of windswept rainy platforms hoping to cross an elusive 4-6-2 off their list.

It was then used to describe listeners who took boat trips out to see Radio Caroline and the other pirate radio ships that surrounded the British coasts. Amazingly, you can still do the same today - and go on board during a live broadcast !

Now... back to the music. [/off topic]

Slippernipper

Just an update here that might be of interest to a storage heater anorak 😊. My flat actually has original 1970s electric underfloor heating which when I moved in, I worked out was too expensive and ineffective to run. No one else in the block that I spoke to used theirs so I figured it was obsolete. 

However last year I swapped to an energy tariff with a cheap night rate and I wanted to experiment with using the UFH like a storage heater at night as it might now be affordable.

So I had some modern programmable thermostats installed, and I’m happy to say my flat is now a constant 20/ 21degrees. The floor comes on at night during cheap hours and the flat holds the heat all day, for a very reasonable cost. 

I will keep the Quantum as a back up over winter

I gather this is how this kind of concrete UFH was supposed to work in the 70s, when it was assumed electricity would be getting cheaper, and there was an incentive to use the grid at night. 

😊

QrizB

Thank you, that's both good news and really interesting!