@dwynwen as I thought it goes nowhere.  Very diligent of the installer to insulate it!

Please let me know how you get on with reducing the hot water.

I think I have asked abut all I can re the washing machine.  I did suggest you disconnect the hose and see what the pressure is like by putting it into a bucket.  That would probably be my next step as it will likely tell you whether its the w/machine or the feed to it thats the problem.

re the noise is something vibrating on the floor upstairs or is it coming through the pipework.  I think you need to try to eliminate some sources.

Re getting the the heating working again, once you have read up about it if you could post

1. A picture of the handheld thermostat

2. The current values of all the 'Field Setting Values' starting 20 which you will have in the installer settings screen, the meansings of these are described on page 26 of the second (Samsung) manual referenced below, but for now we just need the values.  You may need to enter a password which is probably 0202. 

If you can do this I can provide a process to set it up to run efficiently (hopefully)

(Incidentally I think this is the Joule dumbed-down manual for your system, which we may need to refer to in conjunction with the Samsung manual because Joule (suppliers of the cylinder and I suspect the whole package) have, unfortunately,  added some of their own electronics)

In case you haven't got it there is a very useful Samsung manual here https://renewableheatinghub.co.uk/forums/postid/11828   This explains all the intricacies of the installer settings.  You dont need to know them all, but the ones on pages 26-29 are key.  Samsung manuals can be confusing to say the least so, if you understand it first time (or even second) I will be jolly impressed.  You don't really need to understand it at all, just be aware of it.

Hope that helps please post back with info/outcomes.  Given what you have told us about your background you can easily nail this, it just takes a bit of time to understand but once you do understand it its really quite simple.

Update on my situation....

NAPIT have asked installer to come and check things no idea what these are as of yet. 

But progress is progress 

Posted by: @jamespa

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re the noise is something vibrating on the floor upstairs or is it coming through the pipework.  I think you need to try to eliminate some sources.

It might be a pipe bracket transferring vibration into a floorboard.

Simply touching the bracket with fingers would cause the noise to change.

Once we have more idea of

• the source of the noise
• how it's being transferred/amplified

... I can then suggest remedies.

Solutions tend to be simple and straightforward.
You are unlikely to be facing much in the way of costs.

@transparent I have this issue but all the pipework is under the water cylinder if the pipe touching the brickwork isn't the solution as we have already discussed. 

Fingers crossed this year I get to the bottom of all of it 😅

Your insight is invaluable 

UPDATE

After another many more weeks someone is finally coming round today. 

They emailed me 30 mins prior to the appointment....... Luckily I had a day off. 

Seems they didn't want to sort it out as they had jobs on making money instead of sorting their existing customers problems out.

Will update on what that means afterwards. 

So today went well 😁👍

1 lad came round to check things I have mentioned before.

Then later 3 lads come round to sort out some minor issues

I now have a warm radiator that was previously always cold.

They performed a massive system flush.

Auto air bleed valve that was leaking since day 1 replaced.

Pipe going through wall fully insulated now instead of concrete touching copper. 

To be continued 

Said I would pop back with a update. 

Only Mr Jesus himself knows how long it's been now 😅

Heard back to from NAPIT they have contacted the installer and have warned them the buffer sat on the beam unsupported isn't any good thanks @transparent 

They have sent a list of faults hopefully to be rectified 

And thanks everyone else for your input

Posted by: @transparent

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Yes, the knob has an adjustment for pressure...
... but it's also a filter (unless the installer removed the cartridge).

Sorry to resurrect this thread, but it is sort of relevant so on balance putting this here.

But how do you actually adjust the pressure? I have exactly the same PRV and following a burst water main and repair in the road right by my house the pipework now hums, a rather penetrating hole in the head sort of hum, when a cold tap is turned on. Putting a hand on the PRV when it is humming confirms it is vibrating. I suspect the burst water main repair changed the mains pressure and that upset things.

The 'manuals' I have found say there is a hex adjustment screw in the top of the grey cover and the grey cover even has plus and minus rotation arrows on it but there is only a black 'spot' in the centre (big red arrow in image below) which I thought may be a cover for the hex screw but it won't come out even with moderate force applied with a scalpel tip to remove it. Unscrewing the whole grey cap will open up the system (and flood the house if I don't turn the mains off first), rather than adjust the pressure. Does anyone know how to adjust these valves to alter the pressure (I want to try a small tweak to see if it will stop the humming)?