Electric Water Heater Usage

PuddinBear81

I have an Advance Appliances Electric Water heater (not sure of correct name) which is on for 30 minutes in the morning to provide enough water for my day. Unfortunately, this appears to be responsible for a large proportion of my daily energy usage. Temp is currently set to 75. Would any know if it is okay to reduce the temp to say 60 to save on usage, or would I need to then have it on longer to get enough hot water! I've tried googling but not much came up. Many thanks in advance 🙂

xeny

Generally it is considered necessary to reach around 60 to avoid the risk of Legionella growth so you'd be OK on those grounds.

Remember that by lowering the temperature, any mixture of hot and cold (e.g. a bath or shower) would need proportionately more of the now lower temperature hot, so you may not save as much as you hope.

Presuming the device is well insulated (googling with this little information is tricky) you may save a little by insulating any hot pipework associated with it to reduce heat loss a little further.

In your place, I'd be tempted to knock it down 5 degrees, live with it for a few days and then do the same again until I got to 60, just to avoid getting caught out with not enough/not hot enough water all of a sudden.

Rodders53

PuddinBear81 said:

Would any know if it is okay to reduce the temp to say 60 to save on usage, or would I need to then have it on longer to get enough hot water! 

Yes that's fine.  It may or may not reduce electric use significantly though (depends if the 30 minutes ON time is up before 75C is reached inside the tank, or not and if 60C will be reached with a revised setting in that time).
It could reduce heat losses from the HW tank with a lower differential temp (75-20C room = 55C, 60-20 =40C).  Many HW tanks lose a kWh a day or thereabouts.

You might find that you run out of hot enough water at the reduced temp of 60 mixed with cold, but you'll only find that out over time and practical use.

You might look to see how much water (in litres) the tank holds and estimate how much hot water you use each day, plus the immersion heater power rating.  Then someone can do the calcs on energy used to reheat.  https://www.advanceappliances.co.uk/ may help you provide us with the precise model number of your tank to allow more accurate advice.

Hot water energy use, while not to be ignored, is usually small compared to room heating use in winter.

PuddinBear81

Thanks both for your help. I have reduced the temp now with no adverse effects so far, and a slightly reduction in cost