Re-use old thermostat on a new system

[jerry666]

We recently moved into a new house. The original boiler has been replaced with a modern combi. The existing thermostat (15 year old Honeywell) isn't connected. The boiler manual states it can be connected to a 2-wire on/
off volt free heating control, programmer or thermostat.

Can we re-wire the existing thermostat or do we need to buy a new one?

Thanks in anticipation.

 

[D_Hailsham]

You will probably need a new one as most old stats were not volt-free. Post the model no or a pic and we can tell you.

 

[jerry666]

I'm sure it isn't volt free. It has three or four wires for a start.

 

[jerry666]

I'm sure it isn't volt free. It has three or four wires for a start. However will look and see what model number. (Or get a photo). Jerry