When I switch from watching integrated Freeview to my Foxsat I need to increase the volume substantially to get the same level. Any way to get round this irritation?

The Foxsat has it's own independent volume control just turn it up on the Foxsat remote..

Does the Foxsat have variable output level? I know the Humax Freeview units have their own volume control, not sure about the Foxsat models. If so make sure the volume level on the Foxsat is not turned down low and adjust it as necessary.

If there is no volume adjustment or the Foxsat is flat out then there may be nothing you can do. Unless your TV has the ability to set separate volume levels for each input source.

Also how is the Foxsat connected to the TV? By HDMI or SCART? There is a fault condition that can affect a SCART lead that would give you low level audio. Though you would notice more a general lack of low frequency sound and very indistinct dialogue rather than just an overall drop in volume.

It seems to depend on your TV or AV amp setup.
The Foxsat does indeed have a volume control, but with my own setup it will not go as loud as the built in Freeview.
It could be that HDMI doesn't produce as much input or even the transmission.
My Foxsat was installed in February to replace a Sky+ HD and that suffered exactly the same volume limitations.
Same transmissions from the same satellite, different receiver, same TV your guess is as good as mine, but it seems a common problem.