VAT and scrap?

Wondered if anyone knows the position in regards to the following.

I have a client who install new boilers and in the process removes the old ones. They have just taken the scrap (accumulated over a few months) to a scrap metal dealer and received cash for it (circa £700). Whilst I am happy enough that it should be regarded as taxable income for the business I am unsure of the VAT position.

If anyone has come across this (or any case law) before and can indicate if there is a VAT implication for this transaction, the advice would be much appreciated.