Thanks all, apologies for late reply, bought new unit and works a treat. Will test old at later date as multimeter packed up....re. cost calculations, will put Mrs and kids on eBay later ;-)Thanks John. I removed the hose and shower head, the low pressure light turns on briefly then goes out yet the water does not get hot on either power setting ( I believe the low pressure light being on earlier was due to the washing machine being on aswell) the water is not coming out at any great pressure so I suspect the heating element is scaled up or blown somehow...I'm gonna replace the unit tomorrow and post on here how it went .