I have some Stiebel Eltron quartz heaters (IW 120 & IW 180). The IW 180 is half of my main house heating system (the other half is a VEAB duct heater). It's connected via a separate fused timeswitch. I don't use any temperature control but just control the number of hours it comes on, and switch it to one, two or three 'bars' hot. The IW 120s are in our shower rooms just to take the chill off if desired.

The Stiebel Eltron units are pretty basic. Reasonably made but I've had to replace the pull cord a couple of times because it scrapes along the raw edge of the hole in the casing. Stiebel Eltron told me I'd need to replace the entire switch unit including the pull cord, but after I opened the unit I discovered a simple piece of cord just tied to the operating lever of the switch! Maybe the more capable units are a bit better quality.

I've also had to replace the Timeguard timeswitch once. It died and Timeguard sent a replacement under warranty.

Don't know anything about Mylek (is that who you meant?)

Posted By: WeeBeastieAlso, if a wall mounted heater comes with a plug, is there any reason it would be better hard wired?

Dunno. In my case all the heaters are wired through fused units back through radial spurs to individual MCBs in the consumer unit. That's the way my electrician wanted it. I suppose for something that's going to be left switched on for long periods and that draws significant currents there's less to go wrong with a permanently wired solution.

Having said that, my duct heater just came with a length of flex and I've terminated that with a 13A plug and that is plugged in to a TP-Link smart plug that's plugged into a ring main, so I can control it by wireless commands from a Raspberry Pi. I never bothered wiring up the radial for it but it seems to work OK.

We had some Adax Neo flat panel radiators previously in an extension (as backup in case we had underestimated heat load, which we had). We liked them as they didn't click, or smell of burnt dust, as others do. Certainly seemed better made than the cheap fan heaters we had previously.

They had individual digital thermostats and time clocks. AIUI the 'ecodesign Lot 20' product regulations made built-in thermostat and timers pretty much mandatory, maybe that has changed now.

(Edit - they now seem to be available with or without WiFi control)

Seems that they should be ideally be hard wired rather than plug-in:
https://www.electricradiatorsdirect.co.uk/news/do-electric-radiators-need-their-own-circuit/

As your install is only temporary, Id just plug your heaters into the ring mains serving the lounge and bedrooms. Its roughly 4 amps per kw so youve got 5 amps for your lounge ring and 9 amps for the upstairs ring. Unless youve got some exceptional loads on your non kitchen rings, there'll be more than enough spare capacity for a 32 amp ring to supply.

If you put in dedicated circuits for the heaters with fused spurs they will all need decommissioning when the staged works is complete.

Posted By: philedgeIf you put in dedicated circuits for the heaters with fused spurs they will all need decommissioning when the staged works is complete.

Why would you have to do anything other than disconnect the heaters, and maybe switch off the MCBs in the CU?

Perhaps I'm not so precious about appearances then. I don't mind seeing a fused connection unit, even less a blanking plate (I have several in our hose for various reasons). There's been no suggestion of a rewiring, and even if there were I'd prefer to have spare unused cables than not have them (in fact I do!)

@ Weebeastie
Re; fused spurs, you could go ahead and put in the appropriate circuits for your heaters with front cable outlets. Eventually those electrical outlets could be used as a power source for say A/A wall mount indoor units. A 3 split
could easily handle those heating ( or cooling) needs and more.

I would look for a convection heater with optional booster fan in case you need to speed up the warm up rate. eg if you go out you can turn them down/off and reheat quickly when you come back.

With some the fan comes on automatically with heat. On others you can choose to have the fan on or rely on convection. Check with the manufacturer.

I'm thinking something like the Dimplex DXC30F & DXC30FTi (Timer) which are around £50?. Think they can be free standing or wall mounted.

They are slightly odd in that the available modes selected by switches are..

Fan only (eg cold)
1kW fan assisted
2kW Convection
3kW Fan assisted

So you would mostly leave it in 2kW mode and set the stat accordingly. Switch to 3kW to speed up warm up time.

I went with the Stiebel Eltrons in the end as had to make a quick decision. They have vents at the front so not as pretty as the Mill option. But they are tiny compared to the old K2s and are fitted in discreet places. Only a couple are installed so far but they seem to be doing a good job. They are on fused spurs (didn't come with plugs).

A2A is the intention down the line.

Thanks for all input.

Posted By: tonyDirect electric 100% efficient air to air heat pump in the region of 350% efficient, your choice

Don't forget to factor in the fact that the electric heaters as supposed to be a temporary solution for a few years so unless the heat pump is reusable without significant cost then the capital cost of the HP vs. direct electric must be factored in.