@jamespa thank you very much for your detailed reply. I’m sorry it’s taken a few hours for me to respond but I’ve been away from the house most of the day. 
I’ll come back to you as soon as I can with the info you’ve requested.

I really appreciate your help. 

Posted by: @jaynieq

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Weather compensation setting might be a little more problematic. The installer is 3 hours’ drive away, and has shown next to no interest or intent in providing after sales assistance. But I will contact them to request their help. 

The Vaillant WC interface is actually much more user friendly than most.  You can do it without your installer (which doesnt excuse him not helping).

If you could answer some of the questions above I should be able to give some more detail - I now see you have said you will, posts crossed!

@jaynieq - good to hear that you were able to understand my rather long winded explanations and have started to act on them.

Your installer sounds far from ideal. Was it one of those imposed ones where you get a grant, and have to use the grant administrator's 'preferred' installer? I had that happen to me, the 'preferred' installer turned out to be hopelessly incompetent, and in the end I had to insist they were removed and one of my preferred installers stepped in. If your installer is being awkward, then we are where we are. Again, @jamespa, because he has a Vaillant, might be able to talk you through the initial steps. I could if you had a Midea unit, its few soft key presses on the controller, first to turn weather compensation on, then to set the two ends of the curve. I imagine it much the same in principle for a Vaillant.

I think 4+ layers indoors counts as cold! We need to get you warmer!

Edit: having just posted, I note @jamespa has already replied.    

While you are pulling the data together that James needs to help you should also download the MyValliant app. It tells you a lot about your system you need to know. Like indoor and outdoor temperatures and the instantaneous flow temperatures and power usage. In a larger house our daily worst power usage is 66kWh, £13 worst day but £50 in the week, but it is as warm as we want it. In spring it will be considerably less.

With a Vaillant you can be on an OVO special tariff of 15p per kWh

I used to work with a guy who had a solid walled cottage and he always said it took a week to warm up, but he started his heating a week after everyone else. He had a 24hr operation wood burning stove.

@jamespa thank you again…really struggling with internet connectivity today. We’re int sticks and it’s steam driven… I’ll send photos separately, hope that’s ok.

Senso - yes

TRV - yes, radbots

Other thermostat - external air temp

Other heating timer - water thermostat

Wifi interface - yes

myVaillant app - yes but not playing today

Buffer tank - unsure but will send pic later

Occupied - continually as both retired

Elec tariff - still on previous fixed with Octopus as still waiting for DOA

Mother board - see pic

Oil consumption - approx 2000 litres per annum 

Flow temp - not sure if this was included in design info but will confirm asap

Pics to follow 

@cathoderay yes, thanks to your help and @JamesPa  I’m starting to get a little more clued up! As you’ve probably already gleaned, I’m not tech savvy… 🙃

Our grant experience was exactly as you described but instead of taking the reins, we allowed ourselves to be led - trusting that those who assured us that everything would be ok would be true to their word. It’s been an awful experience and the whole system seems like a licence to print money for the ‘trusted installer’.. 

Anyway, enough of my moans! Onwards and upwards… 

@judith thank you for your advice. The myVaillant app is a work in progress. Living in the sticks, we sometimes have to fall back on 3G and today is one of those days. Not ideal!

@jamespa 

Pics as requested, thank you 🙏 

Mother board and buffer tank(?)

Octopus energy usage 

Posted by: @jaynieq

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Our grant experience was exactly as you described

I have asked this before, borrowing from Hopalong as he is known hereabouts, what are the five most terrifying words in the English language? Leave it to the professionals. The trouble is everyone is 'a professional' these days, regardless of actual capability. I hate having to admit this, but these days I tend to assume everyone is incompetent, unless and until I see evidence to the contrary. A sad state of affairs, but perhaps prudent.

I will leave it to out valiant Vaillant professional expert (which he is) @jamespa to comment further on setting up your weather compensation. 

@cathoderay very prudent and I will in the future question everything! 
Well the system is on full tilt (it’s minus 7 here today) and I daresn’t look at the smart meter!

Thankfully this weather is rare. How’s your usage looking..?  

@jaynieq Thanks for the info and pics.  These are of your solar/electrical installation, I was actually looking for the controller etc for the heat pump.  Here is mine, you should have similar parts but they may be arrange differently or attached to your DHW tank.  The figures from Octopus are useful; though as I gives an idea of your usage which, at this time of year, will be largely the heat pump (minus any solar)

You ideally need to get the MyVaillant app working, without it you are flying blind.  Note that it should depend on your wifi/landline internet not 3G, assuming you have landline internet.

So sorry @JamesPa , I’m an idiot. I took pics of everything and then sent the wrong ones! 
Our WiFi drops out continually which is when the mighty 3G kicks in, or 4G if we’re lucky..