Immersion element on all the time?

Travelling Westerly

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Just reading the other thread about excessive power consumption got me wondering if its normal practice to leave the immersion heater on all the time?
I've got into the practice of turning it on once a day for an hour when I need to wash up. Just fitted a brand new tank and expansion cylinder so it's all in good working order, just didn't realise it was designed to be left on all the time?
Appreciate any pointers
Cheers
 
Mine is on a timer, it comes on for 90 mins in the morning, which heats the 30 litres of water, this last me all day, usually. If i need any additional hot water my timer has a button that can be pressed once to turn it on for 1 hour, twice to turn it on for two hours, or another button to override the timer.

Cheap as chips from Screwfix: LAP 7-Day Digital Immersion Timer

There is no technical reason the immersion cannot be on all of the time, other than the heavy load it imposes on your wallet.
 
If the emersion heater has a thermostat 9and it surely must) then it switches off when correct water vtemperature is reached. If you don't use any hot water then it will turn on again when heat is lost through the insulation of the tank. Hence you will find the area around the tank warm. Often used in houses for drying cupboard. This heat loss from the tank is what costs the extra in electricity. In some cases it may suit you to have a bit of extra warmth in the boat. But mostly it is wasted energy. Just how much is wasted is a question Perhaps in the region of equivalent 50 watts continuous. Depending on tank insulation. I think here in oz in domestic hot water supplies using much bigger tanks they are left on all the time. More common in flats than houses. ol'will Rheem Hot Water Systems | Rheem Hot Water Heaters | Hilton Plumbing
 
I think it's OK to leave them on at home (assuming you don't have gas) because the cylinders are invariably insulated a lot better than the hot water storage tank on the boat.
 
Unless the insulation on the calorifier is either very poor or damaged, the loss of heat from 20 - 30 litres of water won't amount to much. We only have access (normally ?) to shore power, when ashore in the winter, and then if aboard, the immersion is on all the time. At home the gas boiler is switched on all the time, but like the calorifier on the boat, only uses power when required. Think of it like your fresh water pump, yes it's connected all the time, but it only draws current when you use water.
 
Yeah ours is uninsulated (all disintegrated and fell off!) and at the very bottom/astern of the aft cockpit locker. We may as well be heating the Mersey! (Not my choice but sorting it is far down the priority list)

Merry Xmas btw.
 
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