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Immersion heater money saving on flexible tariff.

triumph5ta
Posts: 3 Newbie

I thought I would share my good experience that has reduced my electricity bill significantly.
I have a flat with a 3kw immersion heater that provides hot water. The cylinder was replaced about 5 years ago so it is well insulated and crucially it is timer controlled. Heating is by gas warm air which works very well. Ripping all that out and replacing with a combi boiler to provide hot water and heating would be hugely expensive due to the flat layout, long ducting runs to vent it etc...
However, the cost of heating hot water has always been by far the greatest part of my bill. Other electricity use is low, fridge and freezer both new and energy efficient.
I recently found that Octopus Energy provide the Octopus Agile tariff which changes price every half hour. The cheapest hours always include the early morning. My immersion heater timer is set to come on at 02:00 and go off at 05:00 every morning.
Sometimes the tariff goes down to zero per kWh or even less meaning Octopus are paying me to use electricity.
The result is that when Octopus calculate my bill every month they use the average kWh cost I have used over the month. For the last three months this has been a fraction over 13p per kWh.
You will need:
N.B: The price per kWh goes up significantly between around 16:00 and 19:00 every day so that is the time to avoid using the electric oven for example if you can.
If you have no choice but to use an immersion heater then you should save money this way.
I have a flat with a 3kw immersion heater that provides hot water. The cylinder was replaced about 5 years ago so it is well insulated and crucially it is timer controlled. Heating is by gas warm air which works very well. Ripping all that out and replacing with a combi boiler to provide hot water and heating would be hugely expensive due to the flat layout, long ducting runs to vent it etc...
However, the cost of heating hot water has always been by far the greatest part of my bill. Other electricity use is low, fridge and freezer both new and energy efficient.
I recently found that Octopus Energy provide the Octopus Agile tariff which changes price every half hour. The cheapest hours always include the early morning. My immersion heater timer is set to come on at 02:00 and go off at 05:00 every morning.
Sometimes the tariff goes down to zero per kWh or even less meaning Octopus are paying me to use electricity.
The result is that when Octopus calculate my bill every month they use the average kWh cost I have used over the month. For the last three months this has been a fraction over 13p per kWh.
You will need:
- A Smart Meter
- Octopus Agile tariff
- An Immersion heater controlled by a timer.
N.B: The price per kWh goes up significantly between around 16:00 and 19:00 every day so that is the time to avoid using the electric oven for example if you can.
If you have no choice but to use an immersion heater then you should save money this way.
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Comments
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Good to know
Immersion should only need an hour to heat up. So two hour timer is enough, plus reducing the cylinder thermostat a few degrees this time of year will also save on heating costs.
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triumph5ta said: You will need:
- A Smart Meter
- Octopus Agile tariff
- An Immersion heater controlled by a timer.
Better still, a bit of home automation that monitors the Agile pricing and switches the immersion heater on during price plunge events.I'm using Home Assistant with bottlecapdave's integration. If I had an immersion heater and were on Agile, it would just need a heavy duty relay (Sonoff POWR3 ?) plus a few lines of yaml.Her courage will change the world.
Treasure the moments that you have. Savour them for as long as you can for they will never come back again.1 -
2 ways that are very simple to do. I use a Tesla T-Smart immersion which can be smart home integrated. The other option is a smart plug (must be capable of handling 13A) and connecting that to any smart devices. I use solar to power my immersion so when my batteries are full I get the immersion to boost the tank before exporting any excess. When I upgraded my boiler and put in a cylinder I also added solar thermal so it works well in terms or using as much free heat from the sun and then come 1-2pm while I'm at max generation any slack is picked up with the smart immersionSome people don't exaggerate........... They just remember big!0
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