Hi all
Thanks for your responses. To answer the queries:
* I'm diagnosing a ground failure on the element itself.
* The element is permanently in water.
* The element type is an Ecotherm HE111A (available at
www.heatrodshop.com) and uses an alloy element, so very unlikely to have corroded so quickly.
* The water source is my water tank (approximately 250l capacity), which is then filled manually from a standpipe on shore.
* The breaker on the consumer board only supplies one double plug socket. The other socket is in use by my battery charger (Sterling type, 40A smart charger). This charge is used to smart charge my 2 120Ah leisure batteries. I would note that this is not a new addition, and has been used on the boat for the last 5 years without any issue, until recently of course.
* The trip occurred when the timer switched the immersion heater on, not when the timer was switching the heater off.
I'm wondering whether there could be anything else at fault, such as the wiring having a split, or something else which could cause a power surge and blow the element?
Thanks again for your time all!