Dean, here is the link to the video, I don’t have a way to upload the file.
Vaillant 5kW Sound Test
https://1drv.ms/f/s!AhD5yW27785ul_pUjGNB7R7e6vAT3g?e=wiu7zR
I had to wait a while to record, neighbours oil heating was drowning the sound out 
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It’s much quieter! I will share this with Vaillant as there is a clear difference.
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Drag and drop into your message
We’d much prefer you do - then it won’t get deleted and will remain available here.
Ah interesting, when I listen to it on OneDrive directly, it’s quieter. I’ve downloaded it to my phone to compare directly with my video, they sound the same. There is a distinct buzz. Maybe this is normal with the aroTHERM then?
This is just the aural character of rotary compressors; they all buzz to a degree.
Scroll compressors, as per the 10/12kW versions, have a less harsh profile.
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I went to a noisy 7kW unit today. Measured noise levels weren’t that bad - 60 dB with the case on, but it sounded rattly, and the noise transferred through the pipework.
I opened the unit to see what was causing the noise - and it was the pump. Running at 68% speed, the pump was causing all the noise. I didn’t test 100% speed, but the customer tells me it makes a mighty racket, way louder than what you see on the video below.
When pumps was slowed down, the unit is virtually silent - even with the compressor full out. I feel most noise probelms on 7kW units is the pumps.
Have a look at the attached videos;
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That’s weird, as the 5kW and 7kW units use the same pump.
7kw is 1200l/h and 5kW is 860l/h so obviously running faster on 7kW. It’s a Wilo pump and they can be noisy.
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So can you not dial the flow down, do most properties need the 1200L
mine on DHW mode does 1200l, is this really necessary
On heating mode i have a mostly open loops 60%
bedrooms & kitchen dining room are set on stats 780L
Lounge hallway conservatory bathrooms are open loop 900L when all open.
i do get noise from the water ‘dull hum’ in the night so added the noise reduction mode at night, this makes the compressor run at 50rps UFH and 70rps DHW
the pipes from ASHP to airing cupboard are 18m of 32 pex pipe insulated, i think most of the noise is when the pipes pass into my bedroom cupboard making the noise amplify like a drum.
the next job is boxing in with sound lagging.
that would drive me up the wall
Yes, you do need 1200l/h to get the output. You can’t dial it down without affecting the performance and efficiency of the unit. 7kW units are just underpowered and noisy. We stopped specifying them now.
My 5 kW 's pump runs at 70% , around 1200L/h and it’s quiet
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I think there are many 5kW arotherm+ pumps out there that work harder than 68% to get their 840 liters. In general the 7kW pumps will indeed work harder, but I would think if there really is a noise issue with these pumps, the 5kW should be affected too. Probably less frequent, but stil…
It’s definitely compressor vibration causing the issue in my 7kW unit. I monitored the % pump speed and it’s a constant 67% during DHW and 79% during heating. As the compressor speeds up/slows down, the vibrations occur at different rpm’s whilst the pump speed remains constant.
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I’ve noticed that my 7kW is still noisy when it’s cold (between -5c and about 2c) even though the compressor has been replaced. It could be a combination of compressor and pump?
Have you tried to manually adjust the pump speed whilst the unit is being noisy?
How do you do that?
“Conf. heat. build. pump” setting in the Installer-level configuration options on the VWZ AI indoor controller unit.
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You could try setting the DHW mode to ‘Normal’ (not ‘Eco’), trigger a DHW boost which will ramp the compressor to max, then play with the pump speed.
I haven’t had a chance to play around with the pump speed but the pump runs at 100% most of the time, at 50rps compressor speed the pump is at 100%. It only drops to 60% when the compressor is not running.