I just spotted this

[Norman_E]

I have a couple of Dimplex 500 watt convector heaters with a frost watcher thermostat. They are now quite expensive to buy, but are ideal as caravan heaters, and as heaters on board a boat with shore power, to prevent condensation. The Dimplex Coldwatcher heaters now have a list price of £90 and can be bought for about £59. https://www.dimplex.co.uk/product/multi-purpose-heater-05-kw-coldwatcher
I just found this for £14.95 https://www.ukhs.tv/500w_Frost_Watc...598281601933266413707832108007810498736344126 and think it might be an acceptable substitute.

 

[Plevier]

Worth noting the Dimplex has a metal sleeved element - like a kettle element - that runs at a relatively low temperature - below red heat - so is not a fire risk.
I guess this much cheaper one may be an exposed red hot wire element.
Up to you whether that bothers you!

 

[oldharry]

How about this from Homebase for a tenner: https://www.homebase.co.uk/homebase-mini-oil-radiator-500w_p210025

I am using tone this winter in the camper. seems to do the job. But £90 from Dimplex for a 500w radiator? I dont think so.

 

[Norman_E]

Those are good too, particularly at that price, though a bit heavier and you would need to check that the thermostat goes down low enough to use it for frost prevention. I have a bigger oil filled radiator where the thermostat only goes down to about 15 degrees C.

 

[RupertW]

Looks good but much more effective condensation removal by a dehumidifier and a lot cheaper to run as they only marginally heat the boat.

 

[Hydrozoan]

I use a dehumidifier and a 300W tubular greenhouse heater on a separate thermostat for the engine bay area. With the larger oil-filled radiator type, check the instructions/specifications; I looked at a modestly-priced example and found they said ‘Do not use unattended’.

 

[Max Campbell]

We have to frost-protect our carpet cleaning truck-mounted machines, full of thin copper heat exchangers, etc, and we always go for oil-filled rads - they run at much lower (element) temperatures, but are capable of 3Kw if needed.

 

[ghostlymoron]

I was in Aldi recently and they had small oil filled radiators in the middle aisle. I didn't notice the price though.