Hi David,
 
As you will be aware, the mattress takes the brunt of the wear and tear meaning that in most cases, it is not necessary to replace the base every time you change mattresses. If, however, your base is showing signs of deterioration in respect of the spring response, then it may be time to replace. We would always say that if the base is in good order, there is no need to replace it, although there are some retailers out there who would suggest that you need to replace the base in order to get the best from a new mattress, not necessarily so.
 
If you are still unsure about whether to replace your base, please call our office for further advice and guidance. Kind regards.