Damon says it’s nothing some elbows can’t sort out!! 
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Don’t understand why heating engineers don’t use long radius bends where they can to help with flow. I think it is just the cheap 90° are in the bag already.
I was interested that my plumber used all Press fittings when the boiler got replaced. Great innovation.
From my memory it produced some sky high numbers before just crashing to error state and no data until it settled again
Update.
We made the pipe work changes and put a really long straight before the meter.
Same problem occurs.
What’s weird is that you can run the heating at the max pump speed (800l/h) and the Sharky works fine.
But you put the hot water run anything about 600 l/h and it craps out.
Perhaps it’s because the DHW run is so short (3m from outside unit, to plate/tank, then back again)?
You can physically here ‘noise’ around the circuit when you ramp up the DHW pump.
So maybe it’s just something I have to live with (lower pump speeds on DHW) if I want the Sharky in place?
O dear, that’s frustrating, sounds like it would be worth giving diehl metering a call to see if they have any ideas, did stockshed respond with anything?
This actually reminds me of an issue that @johncantor had with a qalcosonic flow meter, it stopped working as well on DHW cycles I think, though I think John switched to a Sontex in the end.
I’ve message stock shed again with an update. No reply as yet.
Will let you know what they come back with.
This is the re-jig.
Yes, there are some bends. But there’s straight before and after as recommended.
But this setup works at 800 l/h on the heating, so 
yes, the Qalcosonic problem was weird. perfect on rad heating, but stopped reading as water rose above 40deg. Never got to find out the cause of the problem Sontex has been fautless
I wish that heating engineers used a pipe bender. There are still 4 right angles to create flow disturbance. A nice smooth, bent pipe would be sooo much better, but 90° bends as so much simpler.
Very odd.
“You can physically here ‘noise’ around the circuit when you ramp up the DHW pump” - Maybe still some air in the system?
Agh this is a very frustrating problem, I’m not sure what else to suggest other than trying to contact Sharky technical support. I was on the phone with Adrian from Stockshed today, he’s received your email but not had a chance to look at it fully yet. Stockshed are very good, but they are a reseller, I think this is a question for Sharky directly.
Have you got some manual air release valves you can open to see if there’s any remaining air in the system?
As a side note the instructions for my Sika flow sensor that I had to install as part of my Samsung heatpump specify that the sensor should not be installed on a vertical downwards flow because of the increased possibility of air bubbles. I know Sharky don’t mention this, but if there is a bit of air still in the system it’s more likely it will be an issue since the meter is located on the downwards leg.
Kamstrup which uses the same ultrasonic measurement technique as Skarky advise against installed on a downward leg (D) but don’t go as far as prohibiting it:
What pressure is the system at? Sharky don’t see to mention anything about pressure, but Kamstrup specify min 1.5 bar - max 2.5 bar
Thanks Glyn
System is at 1.6 bar
I will drop an email to Sharky themselves, see what they say.
We’ve installed auto air vents in two positions now on the water loop side, one right at the highest point on the photo, just before the Sharky.
Maybe the downward position is the problem?
It’s all pretty frustrating. 
As water is heated dissolved gas will be more likely to come out of solution (pressure and temp dependent)…
I guess in a ‘down’ leg bubbles are working against the flow (they will try and float up) which makes it worse?
Useful info to be aware of, not something I would necesarily have thought too hard about otherwise!
I logged a support call directly with Diehl which went to their German helpdesk.
They punted it over to the UK support desk.
Who were going to get their local support technician to talk to me.
Only to change their mind and suggest I needed to report the issue to Stockshed!!
Agh what a nightmare. Is the meter manageable in its current state? Can you just avoid using higher flow rate? I run my system at 16 L/min, I didn’t notice any drop in performance when I reduced it down from 22 L/min. Assuming the flow rate is sufficient to deliver the required energy, running at a lower flow rate results in less pumping power required, therefore marginally higher COP.
Setting my friends Sharky 775 up.
Out of the box the Pri_add is 59!!
So definitely check the ID on your own unit before setting up.
It sounds like it could be anything out of the box!
On my Kamstrup heat meters, the default Meter-Bus IDs are the last 2 digits of the Serial Number. I notice the close-up of your meter (showing the E7 code) has 25 as the last 2 digits of the number below the barcode, so wondering if Diehl/Sharky follow the same convention. Does your friend’s meter have 59 as the last 2 digits there by any chance?
Yes, I’ve also realised this. A fallback method if you don’t know the ID is to do a MBUS scan using libmbus
sudo apt-get install -y cmake
sudo git clone https://github.com/rscada/libmbus.git
cd libmbus
sudo ./build.sh
sudo make install
cd bin
sudo ln -s /usr/local/lib/libmbus.so.0 /usr/lib/libmbus.so.0
./mbus-serial-scan -d -b 2400 /dev/ttyUSB0
Yes, that’s true. We use this script which can be used to set the Kamstrup ID, default to 1
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oooh, that’s a good spot, I will check when I go back and confirm.
Although it is pretty straightforward to cycle to menu 3 and see the pri_addr setting on the unit. 
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Some info here that could be transferred to the docs?
Confirmed. I remembered I’d taken a photo of my mates Sharky and the serial sticker on the front does indeed end 59.
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