Installed and used a Danfoss TP5000 (have a google for it) in my old house. Very good and reliable. It was a programmable stat with a receiver that replaced the timeclock. (Single channel system).
Handy thing is that you can locate the thermostat where convenient/most suitable. The builder had wired the stat in a south facing bedroom. Bedroom cosy- rest of house freezing or bedroom roasting-rest of house cosy. I located the wireless stat in the hall.
Also good as you can program multiple time/tempretures, with 5/2 (weekday/weekend) or 7 day settings. It also has settings for large or small boilers (cycle times), and can learn how long before a set temperature it has to start the boiler as it learns how long it takes to rise to set temperature.
As you can probably see, I think they're great.
And here's a one time offer, cause I want a karma increase - I still have the stat and receiver in working condition (with manuals even!). Remember it is a single channel system, so can replace a single timeclock/wired stat. If it is of use to you PM me and I can organise to post it.