Electric Showers often seem like an economical solution, especially where gas central heating systems are unable to accommodate a shower. However, although electrical shower units themselves are relatively cheap, you will invariably need the services of both a plumber and an electrician to have one installed. Electrical showers demand a large supply of electricity which means a shower circuit must be cabled with thicker diameter cable able to withstand 30 or 45 amps of current (depending on shower wattage rating).
A bathroom is the most hazardous area of a residential electrical installation with regard to electrical shock. Provisions for additional safety and protection against electric shock must be made by way of earth bonding arrangements in the bathroom, and by the provision of a device called a residual circuit breaker, to ensure the area is safe. This increases the cost of providing the electrical circuit for a shower.
Average guide figure for installing a new shower circuit and extra safety features (depending on length of run and existing protection configuration) would be £300.