Hi Tommy,
Your savings will not have any effect on your contributory ESA but they would be taken into account if you exceed 1 yr in the WRAG and need to claim Income Related ESA.
If you have the necessary work done while on contributory benefit you should be careful to keep receipts in case there are any accusations of 'Deprivation of Capital' `(that is, spending the money solely to reduce your savings so that you can claim benefit).
Nothing on this board constitutes legal advice - always consult a professional about specific problems