Online valuations are notoriously innaccurate and are based on the sales, in a very large region, of all house types. Most of these sales will have been of property that has been maintained and staged for profit -- as high a price as possible. YOUR property has probably been minimally maintained for the past 5 years and you want as low a valuation as possible !!
This could all be moot if your equity, as you see it, is well over £5,000. It is really only worth fretting if you think you can get the equity below £5,000 and, therefore, avoid triggering the equity release clause entirely.
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014