Problems with my wi-fi...Technicolor TG582n

[#1]

Hi,
Just wondering if anyone can offer any advice with my Plusnet supplied Technicolor TG582n.
The wi-fi seems very, very bad at times. It's great connected to my main PC,.PS4 and Sky Box using an ethernet cable, but on my other devices that are connected wirelessly, the connection seems spotty at best. With seemingly lots of things interfering with it...everything from the PS4's direct connect hot spot, the microwave, having devices close together at once and a microsoft wireless display adapter. Even when these things are off, the range and stability sucks! It's always been an issue with it since i received, but I put it down to things in my house etc, blaming myself. Having tried a Netgear router in its place though (I forger the model, a friend supplied), that seemed to work perfectly for a good few days before I had to give it up.
Is this a problem with the Technicolor TG582n in particular? Is there anything I can do other than buy a new router? I don't really want to incur the expense. I have tried changing the wi-fi channel to the optimum channel using a wi-fi scanner on my phone, but this didn't help. If there is anything else I can try, I would be grateful if anyone could advise!
Thank you.

[#2]

Plusnet routers are designed down to a price.
You could always go for a second-hand Netgear (or other router).

[#3]

Hi Suarez.
Try re-orientating it. Just moving it through 10/15 degrees might make a difference because it has internal aerials. Move it a bit further away from a wall if it's close to one. Again a few inches can make a difference, especially if it's a partition wall and the plaster board is lined with foil. Try standing it up on an edge.