Calor Gas (LPG) Heaters - A Guide

Choosing, using and refilling a Calor gas heater

Calor Gas Heater Reviews

All households should have a Calor Gas heater as an emergency back-up in case of winter disruption to energy supplies.

During power cuts central heating systems will not work because the circulation pumps need electricity.

During stormy weather, gas mains can be contaminated by floodwater resulting in a supply shutdown.

If your home is at risk of flooding keep a Calor gas heater upstairs, or in the highest safe place you can, so you will still have some heating. See reviews of our recommended Calor Gas Heaters here.

Warning: Never use a Calor gas heater in an unvented room

Don't let an emergency become a Crisis. Our Surviving The Winter Guide  post has tips on preparing for disruptions to your power & heating this winter.

You can save money on delivery charges by picking up Calor gas and Patio gas bottles from  your local B&Q

Home heating shop B&Q Calor gas bottles

How Calor Gas Heaters Work

Portable LPG (Liquid Petroleum Gas) heaters are usually called Calor Gas heaters, after the company which popularized them. They are self-contained units which need no connection to an external energy supply and and are essential for back up / emergency heating in areas prone to power cuts and flooding.

The unit consists of a bottle, containing pressurized gas, which is placed in a cabinet and connected to a burner.

» Read more here about Calor Gas Heaters

Calor Gas heaters are  easy to use and need no specialist fitting, they are the most versatile and popular kind of  portable heater in the UK.

home heating shop calor gas heater set up
The image shows a typical  Heater  set up. With Butane gas bottle, regulator & hose.

The bottle is attached to a regulator,  usually by a simple push fitting with a locking lever at the side.

The regulator feeds the gas through a hose to the burner. The regulator ensures the gas arrives at the burner at a preset even pressure.

The heater is lit by pressing a button which causes a spark, with most heaters this is  piezoelectric so no batteries or external flame lighting is needed.

A full-sized cabinet without the gas bottle weighs about 30 pounds (the same as 4 gallons of water) and can easily be carried by two people.

A  full-sized Calor gas heater rated at 4.2 Kilowatts will last for 50 hours on one 15Kg gas bottle, turn it down to 2 Kilowatts (the heat output of most portable electric fires) and it will last for 105 hours.

You can use our calculator further down this page to see how long your gas bottle will last at different heat settings.

Calor Gas Heaters burn LPG mixed with oxygen from the air in the room, so the room must have proper ventilation to allow fresh air in and any waste gases to escape.
Modern Calor Gas heaters are fitted with oxygen depletion detection systems if the oxygen in the room drops to an unsafe level the heater will shut off.
Most also have anti-tilt safety devices which will shut the gas off if the cabinet is knocked over.

Never use a Calor gas heater in an unvented room.

» Read less

There are two types of Calor Gas Heaters

1. Traditional Open Flame  Calor Gas Heaters

Open flame Calor Gas Heaters work by burning Gas mixed with oxygen (from the air in the room). The flames are visible and give off heat, mostly by convection (warming air) and some by radiation (infrared rays like the suns rays).

» Read more about Open Flame Calor Gas Heaters

Most open flame Calor gas heater cabinets have flames playing over white grid type thermal plaques, others such as the Provence and Thurcroft have coal or log type flame beds.

Calor Gas Provence heater
Provence with coal effect flame bed

Open flame heaters use a system called incomplete combustion, this means about 60% to 70% of the bottled gas is turned into heat.

The rest is converted to waste gases  Carbon dioxide (CO2) and water, all carbon-based fuels produce water and CO2  when burnt.

Incomplete combustion also produces  Carbon monoxide  (CO) which is poisonous if allowed to build up in an enclosed room, rooms must be ventilated to allow the waste gases to escape and allow fresh supplies of oxygen in.

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2. Catalytic Calor Gas Heaters

Catalytic Calor Gas heaters work without a naked Flame. They turn most of the gas to heat without producing poisonous waste gases and are cleaner and safer to use than a traditional Calor Gas heater.

» Read more here about Catalytic Heaters

calor gas
The Campingaz CR5000 Catalytic Cabinet Heater. 3050W
The heaters work by using a system called complete combustion which turns nearly 100% of the bottled gas to heat.
This happens by feeding the gas across a hot plate  (a preheated catalyst made from a platinum ceramic composite honeycomb plate called Cataheat P).
This lowers the temperature at which the gas burns allowing the combustion process to happen at a lower temperature without igniting the gas.
This means no flames and  only heat, Carbon Dioxide (CO2) and water  are  produced!
Because Catalytic Heaters convert over  99% fuel energy to heat and not waste gases, the heating efficiency is higher than with an open flame fire.
Although no Carbon Monoxide is produced you still need to ventilate your room to allow fresh oxygen in and to let  CO2 and water vapour out.

» Read less

How Long Will A Gas Bottle Last?

Checking Your Gas Bottle Levels

Few, if any, Calor Gas Heaters have gas level indicators,  how do you know when your gas bottle is nearly empty?

  • You can try keeping a record of how long you have it on, forget to note it once and you lose track.
  • You can weigh the bottle (a full 15Kg bottle weighs 30Kg an empty one 15Kg), that means disconnecting your bottle every time you want to check it.
  • Or use a gas level monitor, there are 2 types suitable for home use.

Use this handy calculator to tell you how long your gas bottle will last.

home heating shop calor gas bottle in cabinet

Save money & lower your heat setting:- Turning a 4.2 kW heater down from 3 bars to 1 will increase a 15Kg bottles life from 50 to 150 hours.

Magnetic Calor Gas bottle level indicators

These work well on larger bottles. Liquid Gas volume changes with temperature so some have summer and winter readings.

Be careful about sticking them over the weld seams on smaller bottles as they may not give an accurate reading.

See here for a selection of Magnetic gas bottle level indicators :

Calor Gas bottle level gauges

These are more expensive but are the most reliable way of checking the gas level.

The one featured is Calor Branded and guaranteed for 5 years. We recommend it for domestic Calor Gas Heaters using blue (Butane) bottles with a standard clip-on fitting.

For other fittings see Our Calor gas regulators, hoses, gauges and tools product page

We recommend getting 2 bottles,  when one runs out change it over and order a refill for the empty one.

Using Calor Gas Bottles

The gas supplied by Calor comes in various bottle sizes and colours.
The bottle colours indicate the type of gas within the bottleCalor gas bottles

  • Blue for Butane
  • Red for Propane
  • Green for Propane Patio heaters

Other bottled gas suppliers, such as Flogas, use different colours, so check your gas bottle is the right type before connecting it.

Most domestic portable gas heaters use  Butane gas, patio heaters use Patio Propane, other outdoor appliances use Propane because it can be used at a much lower temperature than Butane (down to -43°C).

It is vital that the correct gas type is used as specified by the manufacturer as the appliances will be designed to use that type of gas.

Butane and Propane have different operating pressures, there are different regulators for each type of gas cylinder and they ensure that the gas pressure “at the appliance” is exactly as specified by the manufacturer.

Never attempt to switch cylinders or regulators between Propane and Butane appliances as it is extremely dangerous.

There are some specialist heaters designed to use both types of fuel if the regulators are changed, always seek advice from your local bottled gas supplier before attempting to change regulators on these appliances.