"The entire perimeter of the fire has pockets of free-burning fuel," the service said in its latest advice. "Crews are actively patrolling and dealing with the fire edge."
Among the communities still considered at risk were those at One Tree Hill, Humbug Scrub, Mt Crawford, Kersbrook, Birdwood, Gumeracha, Kenton Valley, Cudlee Creek and Inglewood.
More than 1000 properties in those areas were without power because of the fire.
South Australian Premier Jay Weatherill said 12 homes had been confirmed destroyed and there were fears for 20 others.
"This is obviously enormously distressing to the people concerned. We'll take every effort to try to reach those people before they ... witness the destruction of their homes."
The fire started on Friday at Sampson Flat, about 30km northeast of Adelaide.
Police are investigating if it was sparked by an incinerator on a local property, though the tenant has denied the suggestion.
The man told the Sunday Mail he had not used the incinerator since moving on to the land four months ago.
Yesterday the blaze had destroyed more than 12,778 hectares of scrub and was being described as the worst in the Adelaide Hills since the devastating Ash Wednesday fires of1983. After temperatures in the mid-40s and high 30s on Friday and Saturday, conditions were milder with a top of 31C forecast for Adelaide.
Weatherill said it was vital for authorities to contain the fire's active edges in the cooler weather, with another hot day forecast for Wednesday.
More than 400 firefighters, 80 fire trucks and 14 trucks were involved in fighting the fire, with strike teams and aerial support also coming from New South Wales and Victoria.
Kersbrook resident Deborah was blissfully unaware of the savage blaze at her doorstep until her girlfriend Sharyn arrived home from work with bad news.
Their home was in the firing line of the bushfire.
It looked as if the threat might pass at first, until the early hours of Saturday morning when they heard an unmistakable roar.
The couple were quickly forced to make the toughest of calls: Sharyn would stay to defend the house, while Deborah headed to safety with son Rudi, 15, daughter Rory, 10, and Tink the dog.
They made it to a relief centre in nearby Golden Grove later that day, where hundreds of fellow evacuees faced the same gut-wrenching wait for news of their loved ones and homes.
For Deborah, the news has been good so far. The house is still standing, and more importantly, Sharyn has escaped harm.
"I'm so proud of her," Deborah said at the relief centre.
"She said if she hadn't have stayed, the house would have been gone."
Unable to return home as the blaze rages on, Deborah and the kids and their Maltese-cross-West Highland terrier were put up at a motel overnight.
Hundreds of people, including athletes, tradespeople and the general public, have offered practical help.
From 20 young people with exceptional climbing skills to offers of transport, shelter and food, the community response to Adelaide's outskirts has been exceptional.
A community notice board has been established to take offers of help, with people responding from across the Adelaide suburbs and regional centres. A Bushfires SA assistance page on Facebook had attracted more than 8200 members by yesterday morning.
Other people have been offering support directly to the Country Fire Service and to emergency relief centres set up on the perimeter of the fire zone.
Pets perish in raging blaze
A large number of family pets have died in a fire that destroyed a boarding kennel in the Adelaide Hills.
The ABC reported that the owners of the Tea Tree Gully Boarding Kennels and Cattery in Inglewood used social media to say that, while they managed to save more than 40 dogs, a large number also perished and no cats survived.
The owners said they were devastated by the loss of their home, business and people's pets and had been contacting pet owners individually, the ABC said.
"We love all the animals we have in our care and are devastated by this. Our deepest sympathy to all who have suffered a loss," a post on the business's Facebook page said.
"We have lost a home, business and pets we love and feel so awful about the loss of people's beloved pets."
The ABC reported the Facebook post drew thousands of comments, with people expressing their sorrow over the animals that were lost and offering help.
"So sorry to hear guys," previous customer Hamish Gleeson wrote. "You guys have been amazing looking after our pets."
Sonya Mara lost her two cats in the fire.
"This is simply awful.. I lost my two cats Roger and Remy ... Totally devastated," she wrote.
Lessons learned
Adelaide Hills 2015
• 12,778ha of scrub have been blackened
• 400 firefighters battling the fire
• No one has been killed though two people are feared missing
• 12 homes have been confirmed lost and another 20 believed destroyed
• More than 1000 properties remain without power
Ash Wednesday 1983
• Occurred in the Mt Lofty Ranges and the southeast of South Australia
28 people killed
• 400 homes destroyed
• 200,000ha blackened
• In the Adelaide Hills, a sudden and violent wind change left authorities helpless in the face of firestorm conditions
• Messages to people in the hills were found to be both delayed and sometimes confusing and the response at times questionable
Improvements in between
• There are vastly improved warning systems to alert people to the developing emergency
• Clear instructions are offered from authorities, including the Country Fire Service and police
• Bushfire survival plans for people living in fire-prone areas have also made community response more decisive
• The CFS has improved and refined its fire-fighting techniques with an emphasis now placed on saving lives and asset protection, ahead of bringing fire fronts under control
• New technologies, including the giant air cranes capable of dumping massive amounts of water, have helped.
- Agencies
