doitmyself is correct. Better to use the whole house method. The guy you had out is ...well....maybe needing more training to put it mildly.
Regardless of that, you have an existing boiler which you want to give you a good level of comfort.
As a minimum i would suggest you should firstly fit a room stat. Even a basic £10 one would be better than what you have but if you can spend a bit more, an ideal stat is a honeywell cm927.
This is a programmable wireless roomstat that will give you total overall control of your system, give you comfortable temperatures, and, save you money. (you can even move it from room to room with you if you like). Here is a link for a bit reading up
CM927 7 Day Wireless Programmable Thermostat - Honeywell UK Heating Controls
It is easy to wire up to the boiler if you have basic diy skills but if you are not confident get someone in to wire it.
After you fit a room thermostat (whichever type you choose) turn the boiler up and let the room stat control the temperature.
You may find after balancing the system, this is all you need as in times past radiators were sized to the heat loss of the room so in theory when one part of the house is a certain temperature the rest of the house should be at the correct temperatures too.
In practice this was not always the case due to other heat gains so that is where TRV's come in. These can be set to control the temperature of each room individually eg most people don't like their bedrooms to get too warm so these can be checked back to suit your needs.
If fitting TRV's i would recommend Danfoss. These are gas filled sensors which mean they react quicker and are more accurate and they are the only truly reversible trv's on the market (fit them on any pipe). Danfoss Ras C are not expensive (about a tenner) and are far superior to the types sold in the diy sheds for around the same money. Ras D are a bit more expensive.
A bit more education for you on TRV's and how they can control the temperature of your home and save you money.
http://danfoss-randall.co.uk/PCMPDF/TRVPt5a.pdf
http://heating.danfoss.com/PCMPDF/TRV_euro.swf
How a Danfoss TRV Works
Look through this lot and learn a bit about controlling your system and get back to me with any questions.