A YATE couple who died from carbon monoxide poisoning had not serviced their leaking boiler in 10 years, an inquest heard.

Deborah Coster, 60 and her husband Jonathan Coster, 46 were found dead in their home in Cherington, off Shire Way on Thursday, November 13 last year leading to a joint inquest being opened as they appeared to have been overcome by fumes generated by their coal fire boiler.

Police were called to the couple’s house after 11am and the property was attended by all the emergency services and South Western Ambulance Service sent a hazardous incident response team as a precaution.

The inquest was held on Monday, February 23 at the Coroners Court in Flax Bourton where Dr Peter Harrowing H.M. assistant coroner was presented with findings from Howard Reed, a gas engineer and boiler expert who carried out tests on the boiler after the deaths.

The inquest heard the boiler was in poor condition and four internal flues were "completely blocked", affecting ventilation in the property.

Dr Harrowing questioned the level of maintenance the boiler had undertaken and quality of ventilation.

Mr Reed, from Reed Gas Safety Consultancy Ltd, Newport, said: “If the appliance had been monitored nothing would have leaked into the property. During the tests, I lit the boiler and saw leakage and I knew something was seriously wrong. All four flu-ways were blocked, affecting the ventilation.

“If it was working properly, 0 parts per million of carbon monoxide would have been released, because of the correct seals and components of the appliance which would not allow any gas or fumes to leak into the room."

The tests revealed the boiler released gases containing 1,368 parts per million of carbon monoxide over two hours.

Mr Reed told the court around 500-700 parts are considered fatal and that a carbon monoxide detector alarm will sound if it records a concentration of just 35ppm.

Detective Constable Neil Wood, who was involved in the investigation and attended the scene when the bodies were discovered, said: “Initial evidence was trauma to the head of Mr Coster which was initially treated as suspicious, but after the first assessment we saw this wasn’t serious.

“We provided house to house investigations in the area and were able to discover the property was privately owned, so the responsibility to maintain and service the coal boiler was Jonathan and Deborah’s.

“There has been no evidence to suggest of any deliberate action to take their lives and no third party was found to be involved.”

Dr Harrowing said: “From the evidence seen today, including the expert examinations carried out by Mr Reed, who has had many years of experience of boilers of all descriptions, and had an initial impression of the boiler being in poor condition, it seems the boiler, which was up to 40 years old and appears to not have been serviced for at least 10 years has lead to carbon monoxide leaking into the property.

“This matter has identified to me that it is very important to ensure boilers, of whatever type, are serviced and maintained regularly.

"It's tragic that for the want of maintenance this couple came to their deaths."

Dr Harrowing concluded that the cause of the couple's deaths was acute carbon monoxide toxicity caused by a solid fuel boiler.