Choosing the right heater for your home is all about understanding the space that needs heating.

With discounts galore, there's never been a better time to buy a heater.

The retail margin's shrinking by the day with prices as low as $20 for a fan heater, and up to $1,200 for a big gas unit.

But what's the best heater for your home?

The options are endless: with or without oil, electric fan heaters, big, small, new-fangled, flame-effect electric or gas fires, and solid fuel heaters - the infinite variety's enough to make you see double.

Ingrid Just of Choice say beware of 'flame-throwers'. Her advice is the best heater and cheapest fuel basically depends on the area you want to heat - roughly, for every one square meter, you'll need 100 watts.

Ian Crawford's a heating expert. He's been selling heaters at Harvey Norman for fifteen years and is full of insider tips, dos and don'ts.

Crawford says "it's also the height of the ceilings - if they've got carpet on the floor, that's great because it insulates better. If you've got wooden floors then it's probably going to be colder. If you've got lots of windows you're going to lose a lot of heat."

One of the most common requests is for single room heaters - so what does Crawford recommend for a child's room, and for how much?

Small oil-filled column heaters at 1000 to 1500 watts cost from $49 to $79. An oil-free 1500 watt Dimplex will set you back $99, while popular French panel heaters which don't get so hot at 1500 watts cost between $119 and $299.

The price gas, fan and tile heaters is higher, but the low running costs make up for that. Smaller units can quickly warm up 30 to 45 square meters - which should include kitchen, dining and lounge at around $499 to $850, equivalent to two electric heaters.

However gas heaters can produce dangerous combustion emissions.

"Make sure you've got good ventilation across the areas you are heating. There are some restrictions in some states around the use of these heaters, especially in smaller rooms," Just advised.

"If you just want to heat a very small room for a short period of time during the year then electric might be the way to go. With the electricity prices increasing if you use an electric heater for all your heating right through the home, then you are going to be a little frightened by the bill you end up with at the end of winter," she said.

The cheapest fan heaters (at $20 to $40) warm a large bedroom or lounge quickly. The Dyson's a step ahead however, and even at $475 it's selling like hot-cakes.

Whatever heater you choose you can cut running costs by not letting warm air escape.

"Make sure all the draughts are closed off because that is where heat can escape, and look at the window coverings - 40 per cent of the heat can go out through that glass if you don't have heavy drapes at night-time,"