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520 Wall Mounted Frost Protection Heater

The model 520 is a compact, wall mounted, convector heater, ideally suited to rooms and areas that require a small amount of heat to protect against frost damage. Typical places of use could be in outbuildings, workshops, greenhouses, conservatories, lofts, etc.

Attractive and practical stainless steel construction.
Totally enclosed element.
Built-in thermostat.
Indication light.
Simple wall fixing.
Safety overheat cut-out.
Slim, modern appearance.
IP21, Class 1

Watts Volts Dimensions (mm) Colour Weight
Height Width Depth
520 500 230 245 240 105 SS & Black 1.2

Additional protective wire guard available - Model 520G (285mm x 305mm x 125mm)

520 Wall Mounted Frost Protection Heater


Voltage 230 Vac
Watts 500W
IP Rating IP 21
Class 1 This appliance must be earthed
Mains Flex H05VV-F3G0, 0.75mm
Weight Approx 1.0kg
Height Approx. 24cm
Width Approx. 24cm
Depth Approx. 10.5cm
Thermostat Approx. 5C to 35C

The 520 wall mounted frost protection heater with thermostat is for keeping small rooms free from frost. It is for use within the home or for similar purposes. The heater must only be used in a fixed position and only for the purpose described. The heater must not be used outdoors.

Safety Precautions
The heater should not be installed in areas which are a fire risk, such as garages, stables, or wooden sheds. This also applies for rooms in which highly combustible gases, vapours or dust can develop.

Do not cover the heater as there is the danger of fire or overheating.

Minimum required clearances : From Floor : 200mm
  From Adjacent Walls : 300mm
From Ceiling : 500mm

The heater must not be installed in a shower or bathroom area.

The surface of the heater gets hot. Do not install directly below an electrical socket.

Do not use the heater when the unit or mains cable are defective or damaged. Repairs are only to be carried out by a qualified person.

If the mains cable is damaged, it should only be replaced by the manufacturer or by a suitably qualified after sales service, in order to avoid risks. Non user serviceable.

If the heater is to be connected with a plug, the plug must be accessible.

The heater is ready for use even when at the lowest setting. In order to switch off the frost watcher pull out the mains supply plug or turn off the permanently installed isolator (e.g. Circuit breaker, switched spur etc.).

The heater is an electrical natural convector heater. It is fitted with a thermostat for the correct temperature and a safeguard against overheating. A control lamp lights up when the heater starts to heat up. The thermostat controls the room temperature and switches the heater on or off as necessary. The built in device for guarding against overheating switches the heater off if an overheat situation occurs, it will reset itself again after the heater cools down sufficiently. The heater is always ready for use. To switch off the heater, pull out the plug at the mains.

Mounting and electrical connections

Be aware of keeping to the minimum distances specified. Fix the mounting bracket to the wall. Two dowels (6mm dia.) and fixing screws are provided with the unit. Make sure the mounting bracket is fixed vertically. Screw out the safety screw on the heater. Hang the heater into the mounting bracket, first to the lower and then to the upper claw. Screw in the safety screw. After connecting the plug to the socket the heater is then ready for use.

The heater can also be permanently connected to the power supply by means of a suitable junction box. This must only be carried out by a suitably qualified person. This unit must be EARTHED. It must be ensured that if the heater is permanently connected to the power supply, it can be isolated by means of a fused switch or circuit breaker.

Operating instructions
The rotary knob and the markings on the casing show the setting of the thermostat.

The heater is intended to protect areas from frost. The frost setting will normally be sufficient, if the area is draughty adjust the thermostat slightly clockwise to compensate.

Taking care of your 520 heater

Before cleaning the heater disconnect the plug from the mains and let it cool down. Clean the casing occasionally with a damp cloth. Do not use strong cleaning materials and do not let water get inside.


Possible cause
Does not heat up
(Control lamp does not light)
Fuse blown Check fuse box
Plug disconnected Reconnect the plug
Room temperature higher than the setting If possible set a higher setting for test, then reset to frost setting
Overheat device has reacted Do not cover the unit with any object. Keep to min specified distances

If the fault cannot be rectified by any of the above, contact your local electrician or get in touch with our after sales service.

For added protection fit the optional protective guard 520G.

We reserve the right to make changes.


Prior to commencing any period cleaning or servicing always ensure the supply to the heater is completely isolated Bush Nelson Electric heaters are factory assembled and tested they are non user serviceable.

The heaters are intended to operate for many years, problem free.

Maintenance is limited to keeping both the inlet and outlet areas free from any accumulation of dust or any other foreign materials. This is especially important immediately before the heating season. Any dust build up can be loosened using a brush and a vacuum cleaner applied to the airways to ensure completed removal of any dust . When the heater is first turned on after cleaning an unusual odour may be noted, this is due to the dust particles which inevitably will be disturbed and will be burnt off from the heating element.

If in any doubt always consult a qualified heating and ventilation engineer / electrician for advice.

WARRANTY. Your Bush Nelson Heater is guaranteed for the period of one year from the date of purchase. We will repair or replace at our discretion any part found to be defective.
Bush Nelson cannot assume any consequential liability. This guarantee in no way prejudices your rights under common law and is offered as an addition to consumer liability rights.