For all hobby-greenhouses


4-channel recirculating heater


2 flow circles for an optimal air circulation









2 flow circles near the soil, for even distribution of air.
Heated air leaks out in the house midway.

It mixes with the room air and cools down on plant-compatible temperature.

Only the back flow is led over the plants.




Adjustable attachment borders

can adapted to each greenhouse,
shifted in talness and

fastened with slot screws at the house.




Simple assembly

Fits into each hobby-greenhouse

Additional installation at any time possible

Assembly on not disturbing place

The any condition is a plug socket 240V

Capillary tube thermostat
as special equipment

With this special temperature regulator

you can set up the desired temperature

from  -31°F  to  +104°F.


It works precisely.


It does not rust in the greenhouse atmosphere like the usual bimetal automatic controllers.


It keeps its regulation quality over a long time.




Large customer benefit

· comfortable operation, fully automatic

· new idea with proven technology

· considerable saving of heating cost

· Adjustment of temperature is possible to 32°F

· long life durableness

· nominal electrical power = 2200 Watts

· nominal fan power = 40 Watts

· exhaust achievement approx. 130 Cubic yard per hour

The constantly running fan

with switched on circulating air continuous operation

distributes the warmth also in problem zones.



The gentle air movement helps preventive

against mould fungus.

Against condensation.


Electrotherm 4-channel recirculating heater

Circulating air continuous operation

We recommend this mode of operation.
Small consumption - large advantages

30 days permanent run use only 28,8 KWH


This energy is used to 100%:

a) Ventilation = air circulation (approx. 50%)

b) Engine efficiency = warmth

use for heating of the house (approx. 50%)


Circulating air continuous operation can be also switched off.
See right column.

Selector switch circulating air continuous operation ON/OFF

Night frost


only few hours,

endangers your plants.


The Electrotherm 4-channel recirculating heater protects your plants against frost

and you can extend the greenhouse year

with low energy costs considerably. 

The Electrotherm 4-channel recirculating heater

is not a heater like the usual devices.

It has completely different electrical connection than usual devices.


Lateral sucking in currents are produced by the special wall suspension.

They produce two horizontal air flow circles.


Additionally to the capillary tube automatic controller – see further below -
the electrical connection of the
Electrotherm 4-channel recirculating heater has a

selector switch
Circulating air continous operation ON/OFF

Position 1:  Fan constantly runs
Position 2:  Fan runs only, even if the heating is switched on.



Heat scarcely over 32°F (0°C)

saves energy costs

Usual heaters have got a freeze

protection temperature of  41°F (5°C)

plus/minus switching tolerance.

Thus is in many cases only one minimum temperature of clearly over 41°F (5°C) realizable.

The  Elektrotherm recirculating heater  can be setted up scarce above 32°F. 

Thus it saves much energy.

There are plants, which stand even
under 32°F.

With the capillary tube automatic controller the temperature can be stopped also to any value in the minus range.

Automatic operation with temperature control

The temperature regulator makes sure

that the heating is only switched on,

if the temperature at the greenhouse decreases below the adjusted value
(e.g. 35.6°F [2°C]).

Unadulterated clear garden joy by high safety class.

Heating with electricity means highest guarantee for your health and the greenhouse.

Textfeld: Airflow-schema
Textfeld: Technical changes we reserve ourselves.
Textfeld: splash-proof

Open the spring season when ever you want.

Extend your greenhouse-year by 50% plus X

30 years  Evelyn Zapke

competence + experience


1 = 

Electrotherm 4-channel recirculating heater

2 =

attachment borders, adjustable at height and width

3 =

with slot screws

4 =

Air current reversals
gently and mildly

5 =

Warm air streams
at the withdrawal heated

6 =

With wall rafters in the house middle
Attachment with the same borders (position 2)

 Best prospects for your
greenhouse world


Greenhouse heating systems