I have used one for the last 2 winters in my greenhouse without any problems it has been certainly cheaper then an electric fan heater also insulate the greenhouse with bubble wrap this will help greatly with running costs.

How do you know it is cheaper?

Jonathan
We have pre paid metres and it costs a lot less to run a 700w oil filled radiator than a 2kw fan heater I have tried both It works out about 60% cheaper.
Steve

Ah! So that's how you know. Wish I had one. I never know what's costing what.

Jonathan you can now read your own meter every month if you choose that option which means you just pay each month for what you use and its very easy to see exactly what you use month by month.
Also your suppler can supply you with free monitor which tells you what your consumption is.

Just be careful about how you wire your plugs and sockets. Remember greenhouses are notoriously wet even in winter and a mollusc that decides to nest inside your socket can cause a bad smell that can be the least of your problems! Namely, a short circuit that shuts off your heat on the coldest night.

Thanks for your replies, I think we will probably try an oil-filled radiator rather than the greenhouse fan heater we have since the thermostat on this seems somewhat unreliable and it got down to 3 degrees in the greenhouse the other night (even though we are completely bubble-wrapped!). Any recommendations as to which one to try as some of them, such as the Dimplex ones, state "not for use in a greenhouse"? We have a proper greenhouse double socket installed by an electrician but will certainly keep an eye out for molluscs, thanks for the tip.

With the plug socket wrap some copper tape around the cable and casing this willhelp with snails and slugs it works with mine.

Check out Parwin heaters their thermostats are second-to-none

Thanks for both those tips, I will have a look at those.

Jonathan, if you check the consumption of your oil filled radiator and a fan heater you can easily find out the savings. For example the 700w oil filled radiator uses 0.7kw (divide by 1000 to get in kilowatts) and fan heater is 2kw. Difference between the 2 is 1.3kw. Divide 1.3kw by 2kw and it will give you 65% savings. Hope it helps.