We can deliver anywhere in the UK and Northern Ireland (unless otherwise stated) as well as Channel Islands and Republic of Ireland. For these areas, please call us direct for delivery times and rates

All delivery times quoted are subject to stock availability and delivery location.

Delivery times quoted can vary depending on stock availability and delivery location. Most UK stock items are shipped on a 1-3 day courier service.  Please contact us direct for individual product delivery lead times and rates on specific items.

In all cases, you will be contacted to arrange a suitable delivery date as soon as stock is ready to be dispatched, unless a delivery date can be confirmed at the time of order.

The majority of our products are easy to install but  Flexiheat can put you in touch with a relevant service technician should you require assistance or should you require any installation, repair or service work.

For any technical information, we can provide  technical manuals and guidance from the outset.

Company’s place of registration: Flexiheat UK Ltd 133 Barrack Road,  Christchurch,  Dorset BH23 2AW

Company’s registered office address:   Flexiheat UK Ltd, Unit 49 Azura Close, Woolsbridge Industrial Estate, Three Legged Cross,  Dorset BH21 6SZ

Company’s registered number: 236 9061 01

Telephone number: 01202 822221

Email address:

Our refund policy can be found here: Flexiheat return and refund policy

Waste or Multi Oil Products

Where you require an installed universal waste oil heater, you will need to consider the heat required. This can be worked out from the volume of air to be heated and the insulation level of the building space. The calculator on our home page using these values along with a temperature change value of 20 degrees C (e.g. -4 C to +16 C) to calculate the kW output you will need from your heater.

There are then vaporising and atomising heaters to choose from. The vaporising heaters are most cost effective to buy and are easier to install (requiring only 240v power supply). The atomising heaters are more sophisticated and can be controlled automatically with thermostats. They will also tend to burn more efficiently and require less cleaning but will need three phase power supply (400v) and compressed air supply to operate the burner.

Please contact us for details if you are unsure.

You should always use all equipment subject to the guidelines given in the operating manual. In general you do not need to pre-filter waste oil before it enters the heater. Our vaporising waste oil heaters series have basic wire mesh filter on top of the day tank to protect the heaters’ mechanical parts from larger debris. The burners with the atomising waste oil heaters are typically supplied with a cleanable inline pre heat filter. This is designed to remove sediment and particles that could block the burner nozzle.

Fuel consumption ranges from 2 litres per hour to over 20 litres for and is stated in the specifications for all our waste oil heaters and burners. As well as the size of the building, it is important to consider the volume of fuel available too in selecting your heater. Please don’t forget the heaters are more accurately termed “universal oil heaters” than the more popularly termed “waste oil heaters” as they will burn a full range of oil based fuels including kerosene / paraffin or diesel.

Yes, it is currently legal given the correct permits. Waste oil burners and heaters require pollution prevention and control permits from your local authority (LAPPC). LAPPC is a legal framework for preventing and controlling pollution from certain industrial and commercial business activities. It reduces and controls the potential impact of emissions from these activities on air, water and land. The fee for an LAPPC permit varies according to both the local authority and the business activity. Many local authorities will allow you to apply on line. Background information on waste oil heaters and waste oil burners is in the Information section or can be found on DEFRA’s website or can be requested from your Local Authority.

For more information please go to:

It is possible to retro-fit a waste oil burner onto an existing heater or boiler but you will need to consider the combustion chamber dimensions and the position of the mounting points. It is also necessary to ensure that the burner can be mounted securely and will seal properly. Further information is available on request.

Waste oil is energy rich and safe to burn. From a greenhouse gas emissions perspective, burning waste oil on site is the most effective solution. It saves the emissions of the truck coming to collect it, the energy cost of recycling it and then the further impact of packaging and redistribution. As most waste oil is eventually burned anyway (for power production in generator furnaces) the net impact of burning waste oil on site is generally regarded as positive.

It is important to service and maintain your universal waste oil burner or heater as specified in manufacturers guidelines. If you do this and use appropriate fuel sources, modern waste oil heaters and burners will achieve clean and efficient smoke-free combustion. Care should be taken in disposing of ash residue as specified in the LAPPC permit.

These universal waste oil heaters and burners will effectively burn a wide variety of fuels including conventional 28 sec or 35 sec kerosene or heating oil. The heaters will run successfully on waste mechanical oil (engine, gear, hydraulic etc), used cooking oil (WVO), straight vegetable oil (SVO) and heating oil. Any oils with a maximum kinematic viscosity below 6.00mm2 per second at a temperature of 20 degrees C and maximum ignition temperature not lower than 40 degrees C and density above 0.94g/cm3 will burn cleanly and safely.


A dehumidifier removes water from the air in your home until relative humidity is reduced to the level you choose. Once it has reached this level a good dehumidifier should automatically maintain that comfortable level with no interference from you!

Relative humidity is a measure of how much water is in the air relative to the amount that air could hold if it was saturated. Relative humidity is expressed as a percentage. When relative humidity reaches 100% it is at the “dew point”. In other words the air is “full” of water and that water will start to condense onto any surface. Warm air holds more water than cool air so as air cools relative humidity rises even though the physical quantity remains constant. For every fall in temperature of 20°F/10°C the capacity of the air to hold water is halved. For example air at 80°F with a relative humidity of 50% will reach the dew point, 100% RH when it has cooled to 60°F.

Water is always in the air, inside and outside the home. The amount inside the home varies and is increased by many routine daily life activities such as cooking, washing, showering, making tea and breathing. If you have uncovered water containers in the home like fish tanks etc, then these will also add to the amount of water in the air.

Generally a relative humidity of 50% is comfortable for your home. This will protect your home and belongings, prevent mold growth and control the dust mite population. There is no real need to reduce humidity below the 45-50% mark. To do so will simply cost more in energy while serving no useful purpose.

Most dehumidifiers work by drawing air from the room over a coil cooled to a very low temperature by a refrigeration system. These are commonly known as refrigeration dehumidifiers. The water vapor condenses on the cold surface and the liquid water drips into the water collection bucket underneath.

As long as the dehumidifier you choose is large enough for the area it is working in, and there are no specific damp problems,  then a dehumidifier will normally reduce the humidity to the chosen level within a few days to a week. This timescale does not apply if the room has been flooded, in which case one or more dehumidifiers will be needed and possibly supplemented by air movers and other specialist equipment. This work is usually undertaken by specialised water damage specialists

The answer to this depends on three specific factors. The power of the dehumidifier, the room temperature and also the relative humidity of the air in that room. A 12 litre dehumidifier will rarely,  if ever,  remove 12 litres in a single 24 hour period. Once relative humidity has been reduced to your chosen level the dehumidifier should only be operating intermittently to maintain that level so the amount of water collected in the bucket will be lower still.

As a general rule of thumb you may need to empty your dehumidifiers bucket at intervals ranging from once every two days to twice a day, depending on the conditions. It is only in exceptional circumstances that a properly sized dehumidifier will need emptying more frequently than this, unless of course you have placed it in a very damp room for the first time.

The water collected in the dehumidifiers tank is called condensate, you can use this in your iron or to water the plants! However, it should not be drunk by humans or animals as it may contain traces of substances that could make you, your pets ill.

This is basically down to the size of the room and how wet it is. But in general you will find most dehumidifiers on our site are classed by house size to make the job easier for you to choose. For instance our smallest dehumidifiers are ideal for anything up to a 3 bedroom house. Our larger units are ideal for homes with up to 5 bedrooms. In general terms we would always recommend that you err on the side of caution and if in any doubt buy a dehumidifier a size larger than you may appear to need. Larger dehumidifiers remove more water per energy pound spent and run for fewer hours in a given space than smaller ones. The energy saving will almost certainly be greater than the difference in purchase price.

A dehumidifier prevents mould and mildew growth in two ways. First it dries out the room, drawing damp from the contents and fabric of the room on which mould and mildew will inevitably form and prevents that damp from recurring. Secondly, providing the dehumidifier is set to maintain relative humidity at 50% or slightly below, the air is too dry for mold and mildew spores to develop. Fungi need airborne water as well as surface water to grow!

In an ideal world a dehumidifier would be silent and invisible. The next best thing is to be out of sight and earshot. Unfortunately the first is impossible and the second, while achievable in some cases, be more expensive in cost and effort. If you need to lower humidity throughout your house a whole-house dehumidifier is the best option. It is easy to fit, virtually silent and is the cheapest solution for whole house control. If you are using a portable dehumidifier in a small to medium sized room, a laundry room or a bedroom for example, it is not particularly important where you position it.

All portable dehumidifiers have a water collection container, often called a tank or a bucket,  to collect the water extracted from the air. These buckets are quite small, to keep the overall size of the dehumidifier down, and need to be emptied at least once a day. Because it may not be convenient, or possible, to empty the bucket daily almost all portable dehumidifiers for home use are designed to allow the water to be drained directly as it is collected. This is known as continuous drainage.  In the casing of the dehumidifier a small hole has been cut to allow a small hose ( most of our units come with this hose in the box ) to be attached to the dehumidifier through which the water can be drained. The water is drained by gravity alone so for effective continuous drainage the dehumidifier needs to be raised a foot or two above the floor and the hose run to a floor level drain.

For any other questions you have that are not answered here…