Heat-On Attachments

Safety for your laboratory

Heating without heating bath liquid.

Heat-On Blocks

Replace the heating baths and heating mantles in your laboratory and reduce the risk of fire and burns.

Many chemical reactions need a constant input of heat to speed up the functional sequence. This is usually achieved by immersing the reaction vessel in heating baths.

The Heat-Ons are innovative attachments that work without the need for heat transfer media such as water or oil. This is an efficient way of heating round bottom flasks with capacities from 10 ml to 5 liter.


Your benefits in the laboratory:

Heat-On Blocks

  • enclose every flask perfectly, right to the top
  • provide maximum surface contact
  • ensure rapid heat transfer without oil or water


Unique design:

The Heat-On Blocks are made of PTFE coated aluminum. This guarantees not only the fastest heat transfer and easy cleaning but also scratch and chemical resistance. 


Two series for different requirements:

The Heat-On Blocks are available in standard sizes for round bottom flask and multinecked flasks with capacities up to 5 liter. For reactions with a single flask.

The Multi-Well series complements the Heat-On product range with inserts up to 150 ml. These can be optimally placed in pairs in a Multi-Well holder on the hotplate. This makes optimum use of the available space.

So you can dispense with heating bath liquid with no loss of productivity. Resource-friendly and inexpensive, the Heat-On Blocks help you avoid potential dangers such as burns and minimize cleaning costs caused by oil dripping from flasks when they are removed from oil baths.


The table below shows the heating times of different quantities of water up to the boiling point using different sizes of Heat-On Blocks. The heating plate temperature of the magnetic stirrer used for this purpose was set to the maximum value.

Flask size Liquid


Time to
boiling point
10 ml 6 ml 300 °C 6.8 min
25 ml 15 ml 300 °C 8.0 min
50 ml 30 ml 300 °C 8.5 min
100ml 60 ml 300 °C 8.8 min
150 ml 100 ml 300 °C 10.0 min
250 ml 150 ml 300 °C 10.8 min
500 ml 300 ml 300 °C 16.4 min
1,000 ml 600 ml 300 °C 21.1 min
2,000 ml 1,200 ml 300 °C 35.1 min
3,000 ml 1,800 ml 300 °C 47.3 min
4,000 ml 2,400 ml 300 °C 51.0 min
5,000 ml 3,000 ml 300 °C 75.5 min


Heat-On Attachments

Heat-On 100-ml block

with flask sidearm cutouts

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Heat-On 250 ml Block

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Heat-On 250 ml Block

with lateral flask cut-outs

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Heat-On 500 ml Blocks

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Heat-On 1-l block

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Heat-On 2 liter Block

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Heat-On 3 liter Block

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Heat-On 4 liter Block

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Heat-On 5 liter Block

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Heat-On Multi-Well holder

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Heat-On safety lifting handles

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Heat-On Multi-Well10 ml insert

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Heat-On Multi-Well25 ml insert

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Heat-On Multi-Well50 ml insert

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Heat-On Multi-Well100 ml insert

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Heat-On Multi-Well150 ml insert

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Package Heat-On Multi-Well Basic

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Package Heat-On Multi-Well

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Heat-On Attachments - Accessories

Retort clamp

Boss head

Flask stand & clamp kit (Hei-Connect)

Flask stand & clamp kit (Hei-PLATE Mix 'n' Heat)



Operation-Manual-Magnetic-Stirrer-Heat-ON.pdf Download


The Heat-On addons and bath attachments fit on all Heidolph Hei-PLATE magnetic stirrers with heating function.
All Heat-On addons have a fixing edge, which means that they are accurately centered on plates and can no longer slip.