Have a 9448ES wired to a 9427 panel During a power cut the alarm went of and wouldn't stop when user code was entered Battery is only 18 months old . Tamper alarm went of when I opened box but stopped when code was entered Disconnected battery then reconnected but alarm still wouldn't stop and only stopped when power was restored and code entered Afraid it will happen in event of another power cut What can be done to stop this happening