I was thinking about having four zones downstairs based on usage;
1. Living room, kitchen and utility room
2. Reception room
3. Office
4. Hall and downstairs toilet
Upstairs I was thinking of 4 zones;
1. Master bedroom (ensuite)
2. Two small bedrooms and bathroom
3. Guest bedroom (ensuite)
4. Hall
or should I be putting programmable thermostats in every room and effectively have 14 zones?
This will not create 14 zones. Think of each manifold as 1 zone and not each room. You will have 3 zones, 1 downstairs, 1 upstairs and 1 for domestic hot water.
With UFH, each room MUST have it's own thermostat. You can have bathrooms, halls, very high ceiling areas, as open circuits without a stat. When a room with a stat calls heat, it will also heat the open circuit area, however, try to restrict this as much as possible. En suites are normally installed with an actuator controlled by the bedroom thermostat.
The most important part of the installation is that it is designed correctly and then it is strictly installed to that design specification. It is extremely expensive to correct an ill-installed UFH system. Ensure design flow rates are adhered to and make sure to install a modulating circulating pump such as a Grundfos Alpha2. This will help to maintain the flow rate required no matter how many circuits are open/closed. Also make sure floor insulation is turned up around the perimeter of each room to stop heat loss through sides. This is significant in UFH.
Also inform the UFH designer of the proposed floor covering for each room. This will have an effect on the flow temperature requirement and subsequently on the floor surface temperature requirement.
I would not bother with programmable stats, as they are over complicated to use and easier to control with timeclock/control centre. Standard wheel type are fine. Most UFH manufacturers will have their own types that co-incide with their manifold actuators. On no account install an UFH system without manifold actuators. I have seen this with disastrous effects, i.e. 6 fills of oil per year!