In some cases when you are upgrading from low to mains pressure the KW will increase and the existing home wiring mat not be suitable. In such cases you will be advised of additional costs that may incur.
No allowance for any rewiring of hot water circuit or hot water switch kit.
specialised and not standard stock items. In such cases a second visit will Depending on hot water cylinder model and age some elements may be be required and the cost to supply such a hot water cylinder element may increase by the difference of the specialised element cost and second callout.