@notechknowhow Ooh! I don’t think you have had the pleasure of tearing off the protective film from the front of your Powerwall yet - That is what I call self-control!!! 😃 Toodles.

When contacting both MyEnergy and Tesla, the first thing they are likely to ask is: Have you updated the firmware and your app?

OK, so to summarise you have

A heat pump

Solar PV with eddie and Harvi

Solar thermal

A tesla powerwall

You are lucky enough to have purchased a house with pretty much all the renewable heating technology under the sun, probably about 40Ks worth if you were to have it installed from new!  You should be self sufficient in energy (more likely exporting) throughout the summer, and pretty good in the shoulder season too.  Look forward to very low energy bills, unless of course you are doing something very odd like running a cannabis farm.

That's the good news.  The bad news is that getting the best out of it all is not trivial, unless there is also some sort of energy management system.  Frankly I doubt if more than a tiny handful of 'installers' (if any) have enough knowledge across all the technologies to ensure its optimally set up.  Hopefully it wasn't far off when you bought it, but since something has gone wrong and an installer (who obviously didn't understand it) has 'fiddled' I wouldn't be sure.  Its not fundamentally difficult but it does require intelligent thought and understanding which, sadly, many 'installers' lack.  So over a period of time you are going to have to get to know it.  There may also be people here who can tell you what they have done with a similar system.

To give proper advice you need to tell us more about your house including average energy usage, Capacity of solar PV, Capacity of battery, Heat loss and several other parameters.

Whatever you do bear in mind the basic functions

• Solar thermal can heat DHW only (and possible the space heating if there is a buffer tank and its suitably plumbed)
• Solar PV can charge the batteries, run the house, or heat DHW through the eddi.  
• The heat pump can heat the house and almost certainly the DHW (its not possible to be absolutely certain from the photos, but normally ASHPs are plumbed to heat DHW as well as space heating).  If it is used to heat DHW it will do so more efficiently (by a factor of 2-3) than the eddi/solarPV can
• The battery can time shift electricity.  So it can store electricity when you are generating more than you self consume, then release it when you are consuming more than you self generate.
• Any left over electricity will be exported and you should get paid for it, typically 3-8p/kWh.  There may also be FIT payments due which are based on the total amount generated, these could be up to 45p/kWh so worth having if they are due
• Any imported electricity will of course be charged for typically at around 30p/kWh

So your aim is to minimise your energy cost.  Unless you have a ToU tarrif (do this later) this is best done by minimising the amount of energy you import/maximising the use of self generated energy whilst getting your house to work as you want.  You may want to start off simple and then progressively improve.  You can get even more sophisticated by playing games with ToU energy tarrifs, but I wouldn't go there yet until you have mastered the basics.

The simplest set up that I can imagine, given where you are currently at, is to ignore the eddi and solar thermal altogether, use the heat pump to heat DHW, relying on the battery to store the excess solar.  If you time the DHW heating for the middle of the night it will be hot in the morning, coincides with when you would anyway switch off your heating, and will soak up any energy left in the battery that hasn't been used by the house.  This will work winter and summer and should give a tolerably good outcome, albeit not the best possible.

The next thing I would do (if its possible) is to re-introduce the solar thermal.  The reason I would do this is that its a one-trick pony and if you aren't letting it do its trick then its doing nothing.  This will heat the DHW during the day and so reduce/eliminate the need to heat DHW at night, leaving more stored energy for use by the house or for export.  

If the solar thermal can be got to work Im not sure that ultimately the eddi adds much value.  When there is excess solar PV there will almost always be excess solar thermal as well. 

Hopefully the battery self manages, but you may need to check.

That's just one suggestion for starters, others may have different ideas.

If you are still in contact with your vendor I would ask them how they had it set up.  Given that they have invested so heavily in renewable technology they may well be keen to tell you!

@notechknowhow

What JamesPa said 🙂 The even better news is that I am getting 15p/kWh on Octopus fixed export and the oldest FIT generation tariff (Apr 2010-March 2011) is now 68.3p/kWh.

If you are recieving a FIT tariff payment my advice as soon as you are ready would be to switch to Octopus and opt out of the FIT export scheme to switch to the Octopus fixed export but keep your FIT generation payments. That way you get the best possible return. You may find it easier to switch the FIT payments to Octopus too, but to be honest they pay exceedingly promptly so thats not a hardship.

My octopus referral code is below, if you fancy sharing £100 welcome

SHARE.OCTOPUS.ENERGY "https://share.octopus.energy/mauve-woods-426"

Friend referral | Octopus Energy

The UK's most awarded energy supplier. We're doing energy better - for you and the environment.

@notechknowhow

Did you resolve your hot water heating problem?

@derek-m

Getting there derek-m. As a complete novice I’m on a steep learning curve but getting some great guidance. I’m just digging around now trying to find details requested by the contributors. Having inherited the property with everything installed Ive been struggling to understand how it all works. Cheers NTKH 

Ps I notice contributors have their system details after their submissions - how do I enter those ? Thanks 

@notechknowhow If you go to your profile settings, you will find a space there for them. Toodles.

Posted by: @notechknowhow

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@derek-m

Getting there derek-m. As a complete novice I’m on a steep learning curve but getting some great guidance. I’m just digging around now trying to find details requested by the contributors. Having inherited the property with everything installed Ive been struggling to understand how it all works. Cheers NTKH 

Looking at your previous photo's, the pipework with the darker insulation is for the solar thermal system which is connected to the heating coil at the bottom of the hot water cylinder.

The pipework with the lighter coloured insulation, above the solar thermal coil, I suspect should be connected to the heating coil being supplied by the heat pump. If you trace back along this pipework the flow pipe should be attached to a 3-port diverter valve. The purpose of this diverter valve is to direct the warm water coming from the heat pump to the hot water cylinder or the CH system heat emitters.

I don't have a Daikin heat pump and it is not very clear in the manual (do you have a manual?) how to start and stop DHW heating, so you may need to consult other Daikin owners if you are not certain.

What you need to do is note the position of the diverter valve, and then using the heat pump controller change from CH mode to DHW mode and confirm that the diverter valve moves from one travel position to the other end. There should be an indicating lever on the valve actuator. If you are not certain post a photo of the diverter valve.

If the diverter valve is functioning correctly but you are still not getting the DHW heated, then check the settings within the heat pump controller.

Please let me know what you discover.

@toodles ok thanks

Posted by: @notechknowhow

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Ps I notice contributors have their system details after their submissions - how do I enter those ? Thanks 

Click the gear icon under your profile name (right sidebar) then add your info under signature.

@bontwoody 

thank you sharing those rates in November we switched from the Tesla rate with Octopus to the Flux rate offered by Octopus when Tesla pulled out of the relationship. 
Export rates 

day rate: 18 hours @ 17.42p

flux rate : 2.00-5.00am @ 6.05p

Peak rate : 16.00 - 19.00 pm @ 28.79p 

import rates (respectively)

28.42p. / 17.05p / 39.79p