Disconnecting when downloading

I can't download any games or updates as it just keeps disconnecting. For the record it stays connected to the exchange but it disconnects from the internet.
The service with Zen has been faultless for 17 years but now it's getting to the point where I will have to leave if this continues much longer.
I'm not a very technical guy but looking at a few posts on here, it could be the new Zen gateways. I am on the FTTC unlimited fibre2 package and have been using a Technicolor router which has been faultless for years.

I would dump the years old router for a start.

If you've been with Zen for years then ask nicely and they'll give you a Fritzbox. Just in case that is the problem as suggested by Professor973.

John