Hi first post so be gentle with me! Bought a sandstrom freesat+ box for my Mother in law, tried to set it up but her old sky box only had one tuner input and the sandstrom needs two. If I plug the cable into either tuner 1 or 2 I get 100% reading. Spoke to Freesat support and they suggested a cable splitter. Purchased a new splitter and 2 new cables but when I plug this in I get 0% on both tuners. Does anyone have any suggestions? Would a booster improve the signal?

You can't split a satellite signal very easily. Unlike terrestrial a satellite tuner sends control signal to a lnb. If you can, swap it for a Humax freetime box. They will work pretty well with a single feed. The second tuner is fed by an internal link which is automatically enabled when a single cable is detected on setup (connected to tuner 1).

Is the Humax box intelligent enough to know when both tuners can be used (if both channels are the same band/polarity), or something?

Yes they are. They won't let you set recording combinations that are impossible.

A good use of resources but I can't help but think it might cause a few support calls, like "I could record two channels yesterday but not today, why" and having to explain how satellite transmission works to clear it up.

It's a shame Sky/Freesat haven't really thought about adopting some single cable system like the American satellite companies have done

No to a splitter.
The best thing to do would be to replace the single LNB ( the part of the dish the cable is connected to) with a Quad LNB and run a second cable to the box.

They ought to be ashamed of themselves. Just shows that they use non technical people for their support lines.

Should also have said both tuners can always be used. The restriction is that the second tuner can't record all channels. For Low Band Transponders the second tuner has access to near 50% of the total available channels.

Untrained ones at that... and not working to any script either THAT actually seems rather surprising.

Actually, I wonder if the OP called Freeview in error?

Would you expect Freeview to know very much about a Panasonic Freeview+ pvr.

Freesat may know a significant amount about the freetime units as they designed the UI and are responsible for the additional services (On Demand and Showcase)

First generation (G1) freesat+ boxes are all different.

The UI and software is designed by the box makers. As this is a rebadged unit from Currys etc Freesat wouldn't have a clue (no reason why they should).

Currys technical support should know the answers (I wouldn't hold out much hope).

Inidentally a freetime+ box will apparently work with a splitter (as will a Foxsat-HDR, it's just simpler to use the supplied loop terminal), it took a while to find out they work without one.

If you set up a Foxsat-hdr with a splitter giving control to tuner 1 and he dumb output to tuner 2 it will set itself up in single cable mode and work exactly as it should. I doubt very much if even Humax support would know this let alone freesat.

So a splitter isn't a daft suggestion if the specific box has software designed to correctly identify the restrictions (All Humax boxes do this).

Not a clue if the OP's box will work this way (chances are it won't), it wouldn't hurt to test it to find out.

Freesat can't be expected to know anything about a first generation Freesat+ box, especially one they don't know who made it. Sandstrom is a rebadged box possibly a rehash of the Harvard (Bush etc) range.