http://chubblocksmiths.blogspot.co.uk/2015/07/common-upvc-lock-problems.html

Over time UPVC locks are likely to show signs of wear and tear and may not work properly or in some cases not at all

Whilst replacement UPVC parts are easy to find it is always advisable to contact a locksmith to repair or replace locks to make sure they are fitted properly to provide the optimum level of security
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