Thousands of smoke alarms fitted by the fire service in homes across the region could be faulty, the MEN can reveal today.

They were fitted by the fire service in homes between 2005 and 2008.

The detectors, which meet British Standards, have sealed-in batteries that last ten years.

But the alarms have been beeping when there is no fire or smoke.

Most of the faulty alarms have been going  off in the middle of the night - when houses are at their coldest.

The alarms DO still work in the event of a fire.

But union bosses fear that householders, fed up with the alarms going off, are deliberately breaking the alarms – leaving themselves at risk from fire.

Greater Manchester, Lancashire, and Merseyside brigades are now having to change the devices.

Manufacturers Dicon have launched an investigation.

In Greater Manchester about 300,000 smoke alarms have been fitted in homes – the majority are those made by Dicon.

Currently 200 people a month are contacting the brigade to say their alarms are faulty.

In Lancashire 130,000 alarms were installed between 2005 and 2008.

Kevin Brown from the Fire Brigades Union said: “It is astonishing if the fire service has been fitting smoke alarms which don't work properly. Lives could be at risk if people are disabling their smoke alarms because of the faults.

“If faulty smoke alarms have been fitted in this region then that is of major concern. There needs to be a major investigation to establish what the most senior managers knew, who they told, and what they did to address the problems.

“We need to know why there has been no general warning and programme of replacing alarms.”

A spokesman for Greater Manchester Fire Service said: “The alarm retains the capacity to warn you of a fire. The public can be reassured that they still work.

“We don't know what the reason for the fault is. There has been speculation but we are still in talks with Dicon to establish the reason. Part of our discussions will be the cost to our service of replacing the faulty ones.”

Merseyside Fire Service that ‘thousands’ of alarms had been changed.

Lancashire Fire Service, said: “We are responding by fitting new alarms from new stocks and are in discussion with Dicon.”

All three brigades have switched to a new supplier.

A Dicon spokesperson said: “Firstly, as noted by all three Fire Services, we are working very closely with them to investigate and resolve any issues that they believe they may have with our products. As one of the largest manufacturers in the world, we treat any such matters with the utmost care, diligence and attention.

“The common theme across the statements is alarms beeping. Beeping may indicate a depleted battery warning or, in some alarms, contamination of the sensing chamber. It is important to emphasize, as Greater Manchester has done, that the alarms are designed to continue functioning i.e. detect fires, during any such warning.

“Should a user have a beeping alarm or any concerns relating to their alarm, they should contact their local Fire Service immediately. They will be able to provide advice and, if appropriate, a replacement smoke alarm. In no circumstances should the user disable or remove their smoke alarm.

“In the past 20 years, smoke alarms have saved thousands of lives in the UK and continue to do so on a daily basis.”

The firm said it was important to maintain smoke alarms and added: “In practice this means testing the alarm, using the test facility, on a weekly basis and cleaning the alarm, as per the instruction manual, at least once every six months.

“If an alarm is not cleaned regularly, it will gradually become contaminated by household dust, nicotine where smokers are present. Contamination may lead to an increase in false alarms, warnings of chamber contamination, as above, and considerably shorten the nominal service life of the battery and the alarm itself.

“Our investigations to date underscore this plea for regular maintenance. This applies to any smoke alarm from any manufacturer.”