FOR MOBILES WITHOUT THE OPTION TO SOLELY CONNECT TO 2G THIS CAN BE THE ONLY OPTION FOR COVERAGE IN AREAS THREE CLAIMS TO BE COVERED (WITHOUT REFLASHING THE MOBILE).
Three Mobile is meant to have the ability to swap to the 2G network where there is no 3G coverage. The network it turns to for this is Orange. The menu options on newer phones only lets us select the 3G network, or to use both, not just chose to not connect to 3G.
According to the Three coverage map, I am in an area of the best coverage, with an area of only "good" coverage about 25m from my house.
Things have been getting so bad recently that often texts cannot even be sent or received - yet the phone never swaps to the 2G network. I would guess they are not keen to do this, as they will have to pay for the calls made and received when its not their network producing the goods. Effectively losing the money you have paid for your contract to Orange, seems to be considered as a far worse option of offering you no coverage at all.
I had bought an unlocked "Quidco special" for a tenner with a tenners Vodafone credit to take on holiday with me - to take advantage of the no roaming fees, and to get an extra charger - which left the phone unused when I returned.
So I shoved the Three sim into the cheapo mobile which can only use the 2G network, and all the voicemails and texts withheld due to the dire coverage today suddenly appeared. The call quality was good too, and not even any competing with Zebedee in the background.
The only downside being I now have loads of texts on the wrong mobile which I will have to text to myself and open them after I swap sims back - well I guess every silver lining has to have a cloud!
Lastly, it seems if you do this constantly for two weeks, after receiving a warning to use a 3G mobile, your sim will be suspended. So only use it when you know you will be able to get reception again in the near future on the 3G network. Therefore not recommended to try while camping in mountains for three weeks etc (or visiting my house long term).
The mobiles that will do this are any old or cheap non 3G Orange mobiles - or any unlocked mobiles that do not support 3G .