Concerned members of the public called in the fire brigade when they saw smoke coming from a spire at Norwich's Roman Catholic Cathedral.

But the smoke turned out to be steam from the cathedral's new eco-friendly heating system.

Now, after several unneccessary visits from the fire service, cathedral officials have reassured the public: 'We're not on fire!'

Deacon Patrick Limacher admitted that, while its new bio-mass boiler was reducing its carbon footprint, it had an unwelcome side effect.

He said: 'It's an eco-friendly system that uses bio-mass fuel (wood chippings) from a local source.

'It means that we have eliminated three gas meters, and it's heating the cathedral better than ever.

'But now comes the drawback. When the system is on or being turned off, steam comes out of the exhaust chimney of the cathedral. This chimney is one of the spires on the west end of the cathedral, and does not look like a chimney, and the steam looks like smoke when it comes out.

'People driving or walking by have seen it and have phoned the fire service three or four times believing that the cathedral is on fire.'

He said the steam happens about seven to eight times a day.

The dean, Father James Walsh, said the cathedral had an effective fire detection system which covered the whole building from roof space to ground level. 'In the case of a real fire the system would alert us by means of loud fire alarms,' he said.

He said the new system has proved to be extremely efficient. 'For the first time in its history the congregation at St John's no longer has to endure Arctic temperatures in winter.'

Martin Barsby, for the Norfolk Fire and Rescue Service, said: 'We have been called on a number of occasions to the Roman Catholic Cathedral over the past few weeks, and would like to thank the public for their vigilance.

'We have been talking to the cathedral over this matter and would ask people to be aware of the situation. Having said that, if an individual is in any doubt we would still urge them to call 999.'

Father Walsh said that the 'eco-friendly' nature of the heating has attracted substantial grants, including one from EEDA (East of England Development Agency) and another from BECGS (Bio-energy Capital Grants Scheme).

Have you got a quirky story for the Evening News? Call reporter David Bale on 01603 772427 or email david.bale2@archant.co.uk.