@glynh I am on Octopus Tracker (daily rates) for import and standard fixed (15p) for export.

This year Octopus Tracker has averaged around 22p I think (maybe less) with rates heading lower. 18.45p today.

With our heavy winter usage I cannot see how we can make Flux/Cosy/Intelligent type tariffs work for us. Even though we have decent size batteries (3 x 8.2kw) ....but the inverter can only import at 2.6kwh from grid only (5kwh in total if solar prod at same time). So our ability to maximise our fill at cheap rates does not work for us.
I will consider an inverter upgrade at some point as that will also support a higher Emergency Power Supply (EPS) output.

just checked average Octopus Tracker rates in 2023:

1Jan to 7 May 22.5p inc vat

1Apr to 7 May 20.1p inc vat

obviously actual cost will vary according to actual usage. But vs Gov capped rates around 34p its been an excellent alternative - with no commitment on term if anything changes. It looks to me unlikely that standard or fixed rates will be better than tracker any time soon

@fazel 

Heater Priority,

Mine was currently set to 'Main & Boost On'.

Following discussion above and another test by me I believe 'Boost' will rapidly raise DHW to your set target temp by using immersion. In my case just 43deg.

I have changed to 'Boost heater only ON'. I'm thinking that having "Main" ON probably means that immersion is used as well as ashp to heat the hot water at ALL times - which is unnecessary. If anyone knows - please confirm or correct me!

@tim441 I moved off Tracker in Sep 21 to a fixed rate at ~22.9p (initially in my last house). This was due to end in September otherwise I would have stayed with it through next winter. Over the summer though, I expect to have a surplus, and Flux looks like a good bet as I can maximise export in the peak evening period and I can largely confine my imports to the 19p cheap period overnight.

I agree that Flux may not be the best for the winter. Luckily with Octopus, I'm not locked in, so I can find another combination. I'm tempted by Go, as I can schedule car charging, some spa heating, DHW heating etc overnight, and my Powerwall will charge fully in the cheap period, but Octopus won't allow you to combine Go with Outgoing ATM - I guess I could switch my "exports" (there won't really be any from Oct to Mar) to a different supplier. I will also look at Agile and Tracker.

@fazel I have switched to 'Boost heater only ON' too as an experiment. I'm guessing that I have either (1) stopped the system using the immersion, or (2) stopped the system using the heat pump, but I don't really know which!

I am monitoring my daily DWH energy usage to see what happens, but in addition I have turned off the power to the immersion with a physical switch. This will be fine if (1) is true, but will presumably mean no DHW heating at all if (2) is true. I'll tell you tomorrow after I have my shower...

@glynh Main reason to think about Tracker now is that there is around a 6 month wait list to get on it.

I think the benefit of Tracker over winter (when we have vast majority of usage) would far exceed any marginal benefits from Flux etc.

I did ask Octopus if I could go on Flux for summer and "book" to go back on Tracker in Oct. But they could not take that instruction (not unreasonably!). 

So I'm happy enough with the mix of Tracker import & fixed export.

Agile is probably ok if you can navigate around it with your usage to avoid peaks. But for us with such heavy winter use Tracker was both easier & cheaper. But at least with Agile there is no waiting list.

@tim441 @glynh I have no experience with LG, I've only looked for some manuals online, that's were my text/instruction came from.

I will share two links, one if for short instruction manual for lg from an installer, the other is an lg service manual that mentions this:

• Heater priority
- Heater priority : determine electric heater and sanitary tank heater on and off..
- Example : If Heater priority is set as ‘Main+Boost heater ON’, then electric heater and DHW tank heater are on
and off according to control logic. If Heater priority is set as ‘Boost heater only ON’, then electric heater is never
turned on and only water heater is on and off according to control logic.

I'm to assume that the HP has an inbuilt heater and can control a second one from the cylinder.

https://assets.website-files.com/5d823e46585f05a7268ecd84/627b7cd0e913241ce08670eb_Heat+Pump+&+Stat+User+Guide.pdf

https://www.irishellas.com/files/LG-Therma-V-Service-Manual_MFL68682007_GM_1217.pdf

• Tank setting 1, 2
Descriptions for each parameters are as following.
- Min temp. : temperature gap from Max outdoor temp.
- Max outdoor temp. : maximum temperature generated by AWHP compressor cycle.
- Example : If Min temp. is set as ‘5’ and Max outdoor temp. is set as ’48’, then Session A (see
the graph) will be started when the water tank temperature is below 43 °C…. If temperature is
above 48 °C…, then Session B will be started.
- Hysteresis : temperature gap from target DHW temperature. This value is required to prevent
frequent On and Off of booster heater.
- Heating priority : Determining heating demand priority between DHW tank heating and under
floor heating.
- Example : If user’s target temperature is set as ’70’ and Hysteresis is set as ‘3’, then the
booster heater will be turned off when the water temperature is above 73 °C. The booster
heater will be turned on when the water temperature is below 70 °C.
- Example : If Heating priority is set as ‘DHW’, that means heating priority is on DHW heating,
DHW is heated by AWHP compressor cycle and booster heater. In this case the under floor
can not be heated while DHW heating. On the other hand, if the Heating priority is set as
‘Floor heating’, that means heating priority is on under floor heating, DHW tank is ONLY
heated by booster heater. In this case the under floor heating is not stopped while DHW is
heated.

@fazel

Thanks for those, I found an LG user manual (attached) and an installer manual (too big to attach) online somewhere a while ago too, and there are also a couple of YouTube videos which go through the installer setting. Unfortunately, these don't always clarify the position. Taking your example:

- Heater priority : determine electric heater and sanitary tank heater on and off..
- Example : If Heater priority is set as ‘Main+Boost heater ON’, then electric heater and DHW tank heater are on
and off according to control logic. If Heater priority is set as ‘Boost heater only ON’, then electric heater is never
turned on and only water heater is on and off according to control logic.

When it mentions the "electric heater" does it mean the immersion or the (optional non-standard) boost heater in the heat pump box, or the heat pump itself? Likewise the terms "water heater", "DHW tank heater" and "sanitary tank heater" are also used and not defined. This is pretty much typical for the manuals I found too.

@fazel

I have also been puzzling over that graph. "Max outdoor temp" is reasonably well explained, but no clue as to the benefits of setting it high or low (default is 55).Hysteresis is fine, though my system seems to regard the set temperature as the top of the curve, not the bottom (eg with demand temp at 49 and hysteresis at 4 the temp will cycle between 45 and 49, not 49 and 53 as per the graph). "Min temp", set by default at 5 I don't understand at all. 

@tim441 Thanks, I had no idea there was a wait list for Tracker, and I will add that factor to the mix. My experience with all of my Octopus tariff changes is that they have been done immediately, so that was my assumption here, but in fact they will only migrate 50 customers/day . Do you know whether this is a temporary limit as a result of the energy crisis or are they phasing Tracker out in favour of Agile?

Having given it a bit more thought, I think Agile would be better for me anyway, as it's easy to automate my setup to completely avoid grid consumption in the evening peak and maximise consumption overnight. That should presumably bring my average price/unit below the Tracker price assuming they use similar multiples of the spot wholesale price for the two tariffs  

Posted by: @glynh

↑

@tim441 I moved off Tracker in Sep 21 to a fixed rate at ~22.9p (initially in my last house). This was due to end in September otherwise I would have stayed with it through next winter. Over the summer though, I expect to have a surplus, and Flux looks like a good bet as I can maximise export in the peak evening period and I can largely confine my imports to the 19p cheap period overnight.

I agree that Flux may not be the best for the winter. Luckily with Octopus, I'm not locked in, so I can find another combination. I'm tempted by Go, as I can schedule car charging, some spa heating, DHW heating etc overnight, and my Powerwall will charge fully in the cheap period, but Octopus won't allow you to combine Go with Outgoing ATM - I guess I could switch my "exports" (there won't really be any from Oct to Mar) to a different supplier. I will also look at Agile and Tracker.

 

Please forgive me if I upset anyone, but I am getting a strong feeling of 'Sod the planet, so long as we can do so cheaply'. 🙄