clasped around the insulation rather than directly around the pipework
This would clearly change the resonant frequency of the pipework and may explain why only some people get the issue.
Trying to decide between the 5 and the 7. The 7 would leave a bit of headroom and the 5 bang on the money for heat loss (measured) per the actual outputs that are in an excel sheet. Are many people still finding issues on the 7 with noise?
Hey @Jason
Heat Geek have just posted a video on vibration and isolation and how those hard rubber feet are not decoupling the unit from the plinth.
I have a 7kw unit the same as you and had a few vibration issues even though we are decoupled from the house by 6 metres of underground flow and return. The issue was only on DHW cycles and solved by manually reducing the DHW pump output to 85%.
The reduction in pump speed (heating mode still set to Auto to allow the heat pump to do its thing) has not affected SCOP.
But more importantly, we were at school together, Bromley Hills and Crestwood. Hello!
Daz
Hi Darren,
How are you? It’s been a while. Are you still in the west midlands? It’s strange how you’re a heat pump owner too.
The vibration we were getting was during both DHW and regular heating cycles so we needed something to address both and the rubber fitting have worked beautifully. It’ll be interesting to see how they perform during the winter months. 
Take care
Jason.