I had a disaster on Thursday. My radiator pipe bust and flooded all downstairs of my home :(
I have had someone come out from insurance to dry it up and they have wrtoe a load of goods off like carpets, fridge freezer etc.
I am just a little worried because they are now sending a cost adjuster out to me. Why would nsurance company do this??

I think, tho I'm not sure, it depends on your cover.
If you have a like for like policy the company will find out how much your items are worth at their current value and give you that much money.
If you have a new for old policy they will work out how much to replace your old fridge freezer for one of an equal description.
There's also a ratio thing where if, for example, your entire contents were valued at £50,000.00 and only 10% are damaged then you would only get a up to 10% payout of £5,000.00.
It's nothing to worry about, all insurance companies do it and they have to show that it has been checked as a fraud issue.
Sorry you had such a pain to deal with though.

When our hot water boiler burst and the water came through the ceiling our insurance company sent a loss adjuster.

He came to have a look at what was damaged and then they arrange how much money they can pay out.

they do this to try and bring the cost down as to how much they will pay out.

It doesn't sound like you have much to worry about though as it is the fraudulent claims they are after.