How to combine Satellite and digital distribution

Adoris

Does anyone know how to distribute sky+ hd to 3 other tv's but keep the digital signal to those tv's as my sky + hd box keeps breaking and I need to be able to receive a digital signal to all other tv's when I'm waiting for sky to swap yet another box.

Set up at the moment is:

Digital amp in shed with coax from aerial and 4 feeds to tv's including main tv. Main tv has a sky + hd box via hdmi cable and a digital receiver via scart in case sky box stops working.

Other 3 tv's have built in digital receivers.

My problem is if the coax from aerial needs to be plugged into sky box and then distributed to other tv's via f140 amp and the sky box breaks, how can I maintain signal to other tv's without having to unplug coax from sky box and plug it into digital amp.

I intend to site a global f140 in shed also and then feed all other tv's from this with tv link in each room.

I have no issue with powering the f140 from sky box and can control sky box with new remote from other location as I have done a trial run
but picture is not great as I have plugged the coax into sky box from 1 of the rf out sockets on digital amp.

Would I need to have another aerial fitted. Current aerial has a mast head amplifier as signal is not great.

Any help greatly appreciated.