Vaillant Arotherm Pro 7kw £3,993 (even if apparently it is £500 less than the Plus

Heat geek have already stated that the pro is in fact cheaper!

Tried that over the phone but it was not going to go anywhere as I had already been forewarned that "this is something that is sort of put in at the back-end" 😀  

Another one from Spruce: 

• Estimate cost
• Vaillant Arotherm Pro 7kw £3,993 (even if apparently it is £500 less than the Plus) 
• Vaillant Arotherm Pro 7kw pack £2,415 
• Electrical works £1,050
• Materials £2,100
• Installation £4,500

There may be a glut of requests (strait of Ormuz syndrome - to avoid commenting on obvious root cause..).

Still many installers cannot distinguish a standard initial enquiry from one that includes diagrams, comments on modulation, floorplans, etc.. 

It still doubles installation and install pack. Perhaps we should ask for no controls... 😆 We just want it installed. 😉

I am not planning on getting hands on but will try to get a standard plumber to handle it, in advance on the ASHP install. Like that the estimates do not get get out of control. 

As as you say, the rad design changes need to be sensible, so we will get the rads ourselves. I could post the rad website that the team that did the survey pointed us to for a laugh?

Anyway, we now found a few more rads need changing, just when I thought it was going to be straightforward..

Rad changes are dead easy, Im no plumber but even I can do 2 per (short) day.  Since you are making them bigger redecorating shouldnt be necessary if you do your design sensibly.  Changing pipework (other than the rad tails) is another matter.  This is one thing I wouldn't worry about too much!

If you want it done properly, fitted by a decent installation team and run efficiently and effectively ,it will almost certainly be more disruption than you first envisaged!

Ours on paper was a dream install, however we ended up replacing all the radiators, needed to upgrade a number of radiator runs to get better flow and had many discussions with the fabulous install team on how best to fit everything.

We quickly worked out that as the disruption was going to be substantial, we would be mad not to make sure everything was done now and properly to boot.

I couldn't face having to do more work to the system later down the road!

yes, I know what you mean.

I see that disrupt is to a large extent the disruption in one's home. So if the pipework needs to run longer but it is outside, this is not too much of a problem (even if in case it is too much it may impact the business case...). But if pipework needs to be redone inside, that's clearly disrupt.. 

Anyway, we now found a few more rads need changing, just when I thought it was going to be straightforward..

My HP was fitted on the same wall as my gas boiler and existing megaflo cylinder, the primaries are less than 2m.

It certainly wasn't no disrupt!