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Discussion Starter #1
Just doing the man math on this and got to wondering whether I should stop heating my water with my gas boiler once I get on the Octopus Go tariff.

Usually of course despite the inherent inefficiency of heating water in a tank from a gas boiler, the cheapness of gas per KwH (about a 1/4 that of electric) means that it is better to use gas. However if I am on Octopus Go that gives near price parity per KwH.

So in theory I'd be better switching to use my immersion (which has a timer). Though I have scaling concerns.

Anybody else who moved onto OctoGo switch to using their immersion for water heating?
 

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Just doing the man math on this and got to wondering whether I should stop heating my water with my gas boiler once I get on the Octopus Go tariff.

Usually of course despite the inherent inefficiency of heating water in a tank from a gas boiler, the cheapness of gas per KwH (about a 1/4 that of electric) means that it is better to use gas. However if I am on Octopus Go that gives near price parity per KwH.

So in theory I'd be better switching to use my immersion (which has a timer). Though I have scaling concerns.

Anybody else who moved onto OctoGo switch to using their immersion for water heating?
What is the cost of electricity on Go?

On Agile, I run immersion when price drops below 1.76p / kWh.

I'm on Gas tracker which was 1.6p / kWh when I checked last

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Discussion Starter #3
Oh I dont worry too much about that level of detail, but I think Go is about 5p during the 4 cheap hours at night and I'm on a gas tariff with Octopus that is a wee bit cheaper than that per KwH.
 

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Oh I dont worry too much about that level of detail, but I think Go is about 5p during the 4 cheap hours at night and I'm on a gas tariff with Octopus that is a wee bit cheaper than that per KwH.
12 month fixed on Octopus was 2.6p/kWh before I switched to Gas tracker

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I agree with @Hermit Dave , at the moment only Agile gets the 'leccy price cheaper than Gas even allowing for the lower efficiency of gas to water heat. However I'm on Tracker for Gas so during the winter it may go the other way with Go being cheaper.
 

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Discussion Starter #6
Wow Dave, good knowledge on your tariffs, to be honest most of the time I cant remember who my provider even is, let alone what my tariffs are :LOL:
 

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Discussion Starter #7
I agree with @Hermit Dave , at the moment only Agile gets the 'leccy price cheaper than Gas even allowing for the lower efficiency of gas to water heat. However I'm on Tracker for Gas so during the winter it may go the other way with Go being cheaper.
I wasnt looking for cheaper electric than gas to make the change to immersion, I was more thinking that the near 100% efficiency of immersion heating compared to a gas boiler that is 15 years old and might only be operating at 80% efficiency or even less could make it cheaper to change to immersion heating.

Actually, it's probably only gonna save me a few pennies at best, I'll probably not bother :)
 

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I wasnt looking for cheaper electric than gas to make the change to immersion, I was more thinking that the near 100% efficiency of immersion heating compared to a gas boiler that is 15 years old and might only be operating at 80% efficiency or even less could make it cheaper to change to immersion heating.

Actually, it's probably only gonna save me a few pennies at best, I'll probably not bother :)
Gas is half the price of your of peak Go tariff so makes no sense to heat water worth electricity when it your boiler is not very efficient. If you switch to Agile it may make sense on price plunge days.
 
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If it’s a condensing boiler , you can do some tweaks like ensuring your flow return is lower that output, i.e. you boiler stat is not set too high as they don’t enter condensing mode.

Scale is actually more of a problem on the cylinder wet heating coil than the immersion, as immersions are easy to replace if they scale up, but where we live I’ve nor family have never had problems.
 

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Most people run the hot water tank at a higher temperature than necessary and turning the stat down a few degrees will save more energy than tinkering at the margins with tariff and fuel changes.
Remember you want 60 degrees at the tap to kill legionella, and make sure your cylinder stat is about 1/3rd way up tank, if it’s at the bottom your wasting energy.
 

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What is the cost of electricity on Go?

On Agile, I run immersion when price drops below 1.76p / kWh.

I'm on Gas tracker which was 1.6p / kWh when I checked last

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How do you automate that? I would probably do that if it can be set and forget but not if it means daily fiddling.
 

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Remember you want 60 degrees at the tap to kill legionella..........
Thanks - good point. Although my system is sealed, at mains pressure, and not gravity fed from an open cold tank that can have dead animals in there for years before discovery. Water coming from my hot tap is just as potable and bug-free as from the cold tap, and at the same pressure, making shower blending easy.
 

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Thanks - good point. Although my system is sealed, at mains pressure, and not gravity fed from an open cold tank that can have dead animals in there for years before discovery. Water coming from my hot tap is just as potable and bug-free as from the cold tap, and at the same pressure, making shower blending easy.
oh no worries about bugs then, is it a thermal store you have, if so how do you find it?

IFTTT fused spurs seem non existent, only an app based one....


My in laws have a normal plug on their immersion so could use any plug in controller.
 

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................. is it a thermal store you have, if so how do you find it?
It's a 300-litre unvented mains fed Megaflo with both boiler and immersion inputs. Highly recommended. The insulation is exceptional and the outside is always at ambient room temperature to the touch even if the whole 300 litres are at a usable temperature. No good for airing cupboard fans though. As both hot and cold water is delivered to the taps at mains pressure that can provide high volume power showers up to USA standards. In fact, the hot water is forced out of the cylinder by cold mains input when a hot tap is opened. And can easily cover two, or even the three showers in our house at the same time with no loss of pressure or hot water to any of them.

 

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Discussion Starter #19
Yep got one of those, not sure whether mine's bigger than yours :p but I really like em.
 

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It's a 300-litre unvented mains fed Megaflo with both boiler and immersion inputs. Highly recommended. The insulation is exceptional and the outside is always at ambient room temperature to the touch even if the whole 300 litres are at a usable temperature. No good for airing cupboard fans though. As both hot and cold water is delivered to the taps at mains pressure that can provide high volume power showers up to USA standards. In fact, the hot water is forced out of the cylinder by cold mains input when a hot tap is opened. And can easily cover two, or even the three showers in our house at the same time with no loss of pressure or hot water to any of them.

I've got a megaflo system as well fed by the mains. Are you sure there is no chance of bacteria growing in there if not regularly used?
 
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