I've had this Blackstar HT-5R for a few weeks, and I just tried using the footswitch today for the first time. I'm new to guitar and amps in general, so sorry if this post is stupid. But I need help.

It's a one-button footswitch. I press the button and all it does is turn the sound off. Whether it's on clean or overdrive channel, the button does nothing but turn the sound on and off. I want it to switch between the clean and overdrive channel! Am I doing something wrong here? Does anyone know what the problem could be?
This is a RTFM moment. See if this helps...

"The Overdrive Select Switch (4) on the amplifier must be depressed to allow the footswitch to work."
I own a HT-5R too, and if you haven't got the OD button depressed the pedal does nothing. Still, I reckon the TS is gonna feel pretty stupid after this is sorted ...

Firstly, does the LED come on and go off when you switch? Have you got it plugged into the right jack on the back? Got your levels up? On the OD channel, if you have the volume up and the gain off, or vice versa, you get no volume.

I had some strange behaviour out of mine when I first got it. Followed the manual to the word, and I got nothing, so I plugged it into another amp to test if it was the pedal itself that was busted or the footswitching circuit in the amp (amp worked fine otherwise) and it worked in the other amp, so I plugged it back into the HT-5R and it worked. Dunno what happened, or why, but it sorted it and it's been working fine since.
Thank you guys. I managed to get it working. Still getting used to it so I just messed around with it until it worked.

It does act strangely sometimes though. Like I was just using it and I had the overdrive on, and for some reason the LED on the pedal wasn't working. It just wasn't responding/doing anything when I pressed the button. I turned the amp on and off and it worked fine though. I think it might have been because I forgot to turn overdrive off last time I Turned the amp off...
I just tested on mine. It seems that if the footswitch is in it overrides the OD button.

Amp on, footswitch in, OD button depressed, footswitch changing channels all good. If you turn OD off, but leave the footswitch in, you get no channel switching at all from the OD button. Unplug the footswitch and it reverts back to normal use of the OD button.