Frequently Asked Questions | Hotbox Heaters
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Frequently Asked Questions

FAQ for greenhouse heaters and Garden Products

Q. Why does the pilot burner not stay lit?

A. It is likely that there is dirt/dust and/or spider webs obstructing the pilot burner from operating correctly. Blowing the pilot burner with compressed air should dislodge the blockage.

Q. Why is there soot building up in my heater?

A. There is not sufficient ventilation in the greenhouse. Install a 75mm bore drain pipe along the floor of the greenhouse to the back of the heater and also a small high level vent. This will provide the oxygen required with minimal loss of heat to the greenhouse.

Q. Why is the heater flame burning yellow?

A. There could be dirt/dust or cobwebs in the burner. It can be blown out with compressed air.

Q. I have a 12foot x 8foot greenhouse. What size heater will I need?

A. As a rule of thumb we would recommend a 3kW heater for that size greenhouse.
There is a Greenhouse heater selection chart listed in both the Gas & Electric greenhouse heater sections of this web site.

Q. What is the difference between heating a greenhouse with a gas heater or an electric heater?

A. In terms of the actual heat given out there is no difference but there are some other considerations to be made for adequate permanent ventilation. This does not mean an adjustable window vent or leaving the door ajar slightly because these can be closed inadvertently or by the next person coming into the greenhouse. It means installing a permanent vent or pipe for permanent fresh air. Full details are in the instructions supplied with the heater.

With a gas heater certain products of combustion such as Carbon Dioxide (CO2) are beneficial to the plants and some commercial growers add CO2 to the greenhouse to stimulate plant growth in a controlled way.

Using  an electric greenhouse heater means that you need an adequate electricity supply to the greenhouse which may not be practicable. With an electricity supply installed you can also use propagation mats, timers, electric thermostats, grow lights and a host of other appliances. An electric heater does not need permanent ventilation. Usually in a greenhouse there is a certain amount of humidity or some water splashed about.

Our Elite and Levant electric heaters are IPX4 rated which is the required standard for electric heaters in a greenhouse. This rating means they are splash proof.

Q. Why would I need to use a propagation mat or panel?

A. In the spring temperatures can vary tremendously, even in a greenhouse. To give your seedlings the best and earliest start a heat mat is placed under your seed trays to give a constant temperature boost up to say 12Deg.C at root level. This is controlled by a thermostat placed in the compost and results in a much higher success rate in the quantity of seeds actually propagating. On a cold day the gentle heat will reliably boost the temperature and on a warm day the sun will do its work and the propagation mat will stay off. The result is that you will achieve greater and earlier success reliably with a heated mat .

Many of the cheaper propagation mats are plastic, and although they will have an affect, the heat does not spread through the mat. The mats that we make use an aluminium foil to spread the heat energy giving a very uniform distribution across the whole mat.

Q. Why would I need a fruit cage?

A. The answer is that you will keep a lot more of your crop for yourself. Fruit cages keep birds away from your fruit and vegetables by having a standard 20mm square mesh or by having a 7mm mesh you may keep butterflies and birds away.