How to wire a programmable thermostat

[aj_clee]

Hi,
I am wanting to change my old thermostat to a new programmable one (haven't chosen yet) but the problem is I only have a red and a black wire coming out of the old thermostat and all the new ones seem to need at least 3 wires. I do have a switch underneath the thermostat that turns a fuse on and off if this means anything?
Can anyone advise me on which thermostat to go for or help me with what the wires mean?
Thanks

 

[Hawk81]

not that I don't want to give you advice but it would probably be best to get a quified spark in. you have not give enough info to possibly begin to advise you. and with all due respect your electrical knowledge does not seem enough to do this correctly and safely

 

[aj_clee]

Can you not advise me on what thermostat to buy with the wires that i have got so then i can get someone in to fit it?

 

[jpmiff]

Hi

have a look in screw fix, they do a battery operated thermostat with a NO,COM,NC volt free contacts