"tina" wrote in message
...
Hi,

I have an 8ft x 4ft greenhouse and would like to add a heater to keep
out the cold.
I thought it best to get an OIL filled one rather than the electric
fan type.

I see they go in W rating from 1000w, 1500w, 2000w & 2500w.

Can anyone advise me what size is best?

I'm growing peas, tomatoes & carrots.

Thanks

A 1200W oil filled heater warms our conservatory satisfactorily which is 5
metres square. It is insulated with double glazing and thermal blinds so
this is an advantage.

I would have thought the 1000W or 1500W would be adequate for your needs.
This said many come with dual control whereby some reduction/increase in
heat can be applied. It may be wise to get a higher rated unit with this
control then at least you can increase/decrease as required.