IT IS rare, a wonderful example of craftsmanship, a "real treasure" - and it's a radiator: a Victorian radiator, which is still working. Its importance was only spotted when preparations were being made for a new heating system in St Mary's, Twyford, between Maidenhead and Reading, in Oxford diocese.

An expert in church buildings recognised its importance, and got in touch with the heritage group of the Chartered Institution of Building Services Engineers. Their expert, Frank Ferris, came along to look at it (above) and said that it was "a wonderful example of Victorian engineering craftsmanship".

It had been made by Rosser & Russell, a company that dates back to the late 1700s, although the radiator had probably been manufactured in the 1860s, a dozen years after St Mary's was built. Rosser & Russell still exist today, using the latest technology to provide building services for organisations such as the BBC and the Metropolitan Police.

"I have visited around 500 churches during the course of my search for Victorian heating systems," Mr Ferris said, "and it's the first example of this company's early work that I have ever seen. It could well be unique at this time."

Because of its historical and heritage value, the church now plans to keep the radiator - though no longer working - when the remainder of the present heating system is removed. The Priest-in-Charge of St Mary's, the Revd Simon Howard, says: "We might even get round to putting a little plaque above it, to show future generations just how special it is."