Choosing a Mill heater

We generally recommend 70 to 100 watts of power per square meter, depending on how well isolated the building is. For larger rooms you may want to use multiple heaters in order to get enough wattage to properly heat the room. A larger and more powerful heater will of course heat up the room faster than a small low wattage heater. If you do not have enough watts there will be a limit in how much the room can be heated, especially during the coldest months of the year.

All electric heaters are 100% effective, as every watt of electricity used is converted to one watt of heat energy. The control panel and WiFi module use a negligible amount of power.

All Mill panel heaters have a low surface temperature. Our glass panel heaters are especially child friendly as glass does not hold heat as much as steel. Our 600, 700, 1200 and 1300w glass panel heaters have the lowest surface temperature. All panel heaters are equipped with an overheating protection which will cause the heater to turn of if it gets too hot.

Mill panel heaters come with 1.3m long cables as standard. This is always attached on the right side of the heater. Our smallest 250w heaters have a 0.8m long cable. There are different rules in different countries, so if you need a longer cable on your heater, you should ask a qualified person.

In a typical room, the coldest area will be right underneath windows. We therefore recommend placing a panel heater under windows so that it can heat up the cold air right away.

Specific rules vary from country to country, so please check regulations in your country. All Mill panel heaters are IPX4 certified meaning they can withstand water splashes.

Both kinds of heaters have pros and cons. A panel heater has an aluminium heating element which is in direct contact with the air. This allows the heater to quickly heat up a room. An oil heater takes longer to heat up, but the advantage is that the oil is not in direct contact with the air. This makes for a more pleasant air quality.

A convection heater is based on the fact that hot air rises while cold air sinks. Convection heaters take in cold air from bellow and lets out hot air above. This is an effective way of heating a room because it creates air flow without any moving parts. When the warm air from the heater loses heat, it will sink back down to the floor and the process repeats. There are many kinds of heaters that use the convection effect in this way.

No, not all heaters are certified for use without supervision, please check rules in your country as well as the product information for specific models. All panel heaters can however safely be used without supervision.

All our heaters with LED displays will display the current target temperature. For example, if you have 18 degrees Celsius in the room and the heater is set to 22, the heater will heat until the temperature reaches 22, and then stop heating until the temperature begins to drop. The heaters have an LED light that is on whenever the heater is producing heat.

Heaters with mechanical thermostats are less precise. They have a dial that you can turn freely. The minimum value on the wheel is approx. 5 degrees. Max value is approx. 35 degrees. If the wheel is set halfway up, this corresponds to approx. 22 degrees.

Not very much. Both types are the same except for the front panel. It’s worth mentioning that Mill glass generally has a lower surface temperature, because glass does not retain heat as much as steel does.

Yes, just as you can at home. You only need a Mill WiFi heater or WiFi socket and a WiFi router with internet access. You don’t need a hub or any other special hardware. You can easily switch between different houses on the home screen in the Mill app.

Mill WiFi Socket

The Mill WiFi Socket is a small device placed between a “dumb” heater and the wall outlet. The WiFi Socket is equipped with a thermostat that allows it to turn a heater on and off to maintain a selected temperature in the room. WiFi Socket has the same options for weekly programs and timers as our other WiFi heaters.

Mill WiFi socket is certified for 10 amps and 2300W. It will work with most heaters on the market but with some exceptions.

  • It’s important that the connected heater remembers its temperature setting after losing power. If you for example have a heater with a digital display that is always at 20 degrees when you turn it on, this will cause conflicts as the heater will not want to heat any more than 20 degrees.
  • We recommend setting the connected heaters target temperature quite high, for example 25 degrees. This way the WiFi Socket can control the heater without the heater stopping to heat too early.
  • Please note that the WiFi Socket should only be used with heaters certified for use without supervision.

Yes, the WiFi socket has an option to disable the temperature sensor. This will turn it into a WiFi controlled on/off switch. It can for example be used to control a lamp, radio, or dehumidifier. There is also a timer function which can do this automatically at specific times of the day.

The WiFi Socket contains small electronic components that generates some heat. The temperature sensor itself is located on the bottom left corner of the WiFi Socket so that it is underneath the warm components.

If the WiFi Socket is mounted upside down or pointing out to the left, this will cause heat from the internal components to affect the temperature readings. To avoid this, the socket must be placed pointing down (Mill logo should be upright) or if that’s not possible, it should be mounted pointing out towards the right.

If the socket is placed correctly but you still experience inaccurate temperatures, please see our guide about calibration.

Mill WiFi

An independent device is a device that is not associated with a room in the app. Units linked to rooms will follow a specific weekly program and change temperature accordingly. You can have several units in the same room.
Independent units are controlled individually. They will not follow a program and are instead controlled by a simple temperature slider and an on/off switch. The Mill WiFi Socket has some unique features that can only be used when set up as an independent device. These functions are cooling mode and the ability to disable the temperature sensor.

Yes, the app has a “Share house” function. This allows you to give other users access to your devices.

With generation 1 and 2 heaters, this is not possible. When these are connected to WiFi, only WiFi can affect the temperature setting. However, you can easily turn WiFi off temporarily by briefly pressing the heater’s WiFi button. Press the button again to connect to WiFi.

With generation 3 heaters, you can change the temperature with the physical buttons even when it is connected to WiFi. You can activate child lock or commercial lock in the app if you do not want this to be possible.

All our heaters except those produced before 2013 have a memory function. This meaning that if the heater loses power, it will remember the temperature when power returns. WiFi devices will automatically reconnect to WiFi after a power outage.

We have 3 different WiFi generations. Here is an overview of the serial number prefix for each generation. The serial number is found on the product itself.

Generation 1:


Generation 2:


Generation 3:


Please note that these serial numbers are also used on heaters that do not have WiFi. WiFi models can easily be identified as they have “WIFI” as part of their model number and also a WiFi button.

If you have a new network or have changed the network name/password on your WiFi system, the device must be reset and set up again. You can add it to the same room/house in the app as before.

Physical troubleshooting

All Gen 3 WiFi Panel heaters, Gen 3 WiFi Oil heaters, and Gen 3 WiFi Convection heater (CO1200WiFi3):

– Turn the heater off if it’s already on
– Turn it back on
– As soon as you see the display light up, press and hold the Settings (gear) button on the heater for 20 seconds (until the display says “Fr” for factory reset)

Generation 3 WiFi-socket

– Press and hold the devices WiFi button for 5 seconds. Wait at least 10 seconds before setting up a new connection.

– Important: If the Child lock has been activated on the socket via the app, you must first deactivate the Child lock by holding the socket’s WiFi button for 20 seconds. Afterwards, you can do a reset by holding the button for 5 seconds.

Generation 1 and 2 WiFi panel heaters, and all panel heaters without WiFi:

Turn off the heater’s main switch. Then hold down the settings (gear) button while turning the main switch back on. The display will then show a count. When the display shows 22, it has been reset.

SG1200 and SG1200WiFi:

Turn off the heaters main switch. Then hold down the temperature dial while turning on the heater. When the display shows 22, it has been reset.

Generation 2 WiFi Socket:

Press and hold the WiFi button for 15 seconds to delete the device’s WiFi settings. Then take it out and in from the wall outlet. It should then flash green quickly when you briefly press the button.

All oil heaters with LED displays, except generation 3 WiFi:

Turn off the heater’s main switch. Then hold down the settings (gear) button while turning the main switch back on. The display will then show a count. When the display shows 22, it has been reset.

Mill Sense

Press and hold the button on the top of the device for 5 seconds. Then, wait until it stops flashing.

The temperature sensor should be accurate down to plus/minus 0.2 degrees, but deviations can occur if, for example, there are air currents in the room or if the heater is placed some distance from where you normally are in the room. Most heaters with a digital display can be calibrated to compensate for this. Refer to the user manual for your heater for guidance.

WiFi heaters as well as WiFi Socket can be calibrated via settings in the Mill app.

Heaters with a mechanical thermostat, as well as heaters produced before 2017, cannot be calibrated

None of our heaters should be particularly noisy. It is normal for them to make a small clicking sound when the heat is switched on and off.

Mill generation 3 panel heaters are 100% silent. If you experience an unusual sound from the heater, please contact the shop or supplier of the product.

Oil heaters can make some noise from the oil inside moving as it heats up. The fan in our fan heater models will also naturally make some amount of noise.

All Mill heaters with LED displays have a lightning symbol in the display on the heater that tells you whether the heater is heating or not. If this symbol lights up, the heater is currently heating up.

If the heater does not heat up as expected, even if the lightning symbol is on, this may indicate that there is something wrong with your Mill heater. To test whether the heater is defective or not, do the following:

  1. Reset the heater (does not apply to ovens with a mechanical thermostat)
  2. Set the heater to the max temperature (35 degrees)
  3. Within a couple of minutes, the heater should be noticeably warm. You can check this by placing your hand over the on the top of the heater
  4. If the heater does not become warm, contact us, or return to the shop where you bought the heater. NB! Remember that you must present a receipt

All Mill Gentle Air Oil Filled Radiators, except the AB-H700MINI, have three different power settings. The heaters have a button that cycles between these levels:

  • 1000w oil heater: 400/600/1000w
  • 1500w oil heater: 600/900/1500w
  • 2000w oil heater: 800/1200/2000w

App troubleshooting

If you are not able to reach the server, please check service status here.

If the server is OK, the problem can be caused by something local on your device. Try logging out and back into the app (via Settings – Personal information). If you are connected to an office network, have certain firewalls on your network, or are using a VPN, this can prevent the app from communicating with our server. Some work phones with high levels of
security features can also cause problems.

Outdoor heating

ULG is short for Ultra Low Glare. This is a special type of heating tube which makes significantly less visible red light than a conventional infrared heating tube. Simply put, ULG heating tubes give a more comfortable light when the heater is in use.

Our outdoor heaters use infrared light with a short wavelength. The heater heats up what the light hits, and not the surrounding air. This gives over 90% heating efficiency. Note that an infrared patio heater is very directional, so you should think about where the device is directed. This can be compared to sunlight – Things that do not get light from the outdoor heater on them will be not be heated up much.

Compared to cheaper or older outdoor heaters, our outdoor heaters are very efficient. Simpler outdoor heaters that use quartz-halogen or steel tubes, by comparison, only have 60% and 40% heating efficiency, as these must heat the air around the unit. This takes time. An infrared outdoor heater will provide full power and noticeable heat a few seconds after switching it on.

Yes, most of our outdoor heater models use the same remote. The remote uses IR signals, meaning it must be pointed towards the device you wish to control.

The following models do not use the same remote as the rest, but you can still control multiple devices with the same remote provided they have identical remotes:

  • T2000D (No longer for sale)
  • JDB1500CL
  • CB1500Basic and CB2000Basic

This completely depends on how many amps the fuse has, as well as how much power is currently being drawn from other devices.

You can easily calculate the total amount of watts a fuse can handle by multiplying the amperes on the fuse by 230v (assuming you are in a country that uses 230v power). Example: 16 amps x 230v = 3680w. So a 16 ampere fuse can handle approx. 3680 watts before it triggers.

Some outdoor heaters will need a slow fuse. It’s normal for an outdoor heater to draw significantly more electricity than the stated wattage as it is being turned on. A 2000w outdoor heater might draw over 3000w the first seconds after it’s turned on, but after a short amount of time it should go down to 2000w. Due to this you will need a fuse that doesn’t trigger as soon as it’s sensing a high electricity load, and this is where a slow fuse comes in.

Some of our models have a so called “slow start”, meaning that it will gradually increase the power level as you turn it on, and it will therefore never go above the stated wattage. These may be used with a normal fuse as long as the total load on the fuse doesn’t get too high.

Check our product overview for more information about what kind of fuse you’ll need for different models.

All our wall mounted outdoor heaters may be placed upside down, for example if you need the power cord to be on the other side. You may also place the wall bracket underneath a half ceiling or something similar. The most important factor is that the minimum distances outlined in the user manual are being followed.

All our wall mounted outdoor heaters come with a standard set of wall screws that work with concrete and wooden walls. This might not be the correct kinds of screws for your wall, so we recommend talking to a hardware store about other screw options.

Yes. All our outdoor heaters are designed to be outside year-round.

Troubleshooting Mill Outdoor heating

You can order a new remote directly from us. You’ll find our contact form here. Please note, we only ship spare parts to Norway.

All our outdoor heaters will start in standby mode when you first turn on the main switch. After that you’ll need to use the remote to turn on the heat. On most models you will need to use the remote, with a few exceptions:
Some models also have a switch to turn on the heater. CB2000BT-ULG has a small button next to the main switch that can be used to change between different power levels. JCD1500CL also has a switch at the top that changes between different power levels.

In addition to this, most models released in 2022 or later have a main switch with three different positions. “0” means the heater is completely off, “I” will set the heater to maximum heat output constantly, and “II” will set it to normal standby mode where you can use the remote to control the heat output.

If your outdoor heater doesn’t turn on, the first thing you should do is double check that there’s electricity in the outlet and that it complies with the requirements specified in the user manual. It’s also possible the remote needs new batteries.

If the indicator light is turned on, but you feel no heat coming from the device, it is likely due to the heating tube being defective. Heating tubes are covered by our 2 year warranty for consumables. On most of our outdoor heaters you can change the heat bulb yourself, with a few exceptions. If you need of a new heating tube, please contact us directly.

For safety reasons the outdoor heater will only send Bluetooth signals while it’s turned on and heating. This is to prevent unwanted people from taking control of it. To enable Bluetooth control of the heater, you will first have to turn on the heater through the remote or by pressing the button on the side of the device. The app should then be able to find it. If you wish, you may change the setting “Device Bluetooth Control” in the app so that the device is always available on Bluetooth as long as the main switch is turned on. You will then be able to turn the heat on and off using the app.