Programmer or room stat

[Graemevw]

I need to move our heating thermostat to a more appropriate place.
Its an old system with an old dial thermostat.
I figured i might as well buy a new thermostat but then wondered if i should get a programmer and get rid of the old mechanical timer too?

Our system is gravity fed hot water, pumped heating. It has one motorised valve to divert hot water to heating or hot water cylinder, the pump, cylinder stat and an electric heating element in cylinder (never used).

We have no TRV if that makes any odds.

If i am best getting a programmer, what will i need? Our system is pretty simple so i guess anything will be ok?

Easy enough to wire up? There is a very messy junction box at the moment with loads of tangled wires

 

[dcawkwell]

You will need keep the old mechanical timer for hot water.

You can use a programmable room thermostat to give yourself
a number of settings for the day.

 

[Graemevw]

Ok, thanks.

 

[Graemevw]

Been looking at programmers and im a bit confused now.

If i get a digital room stat and use the timer functions for the central heating, how do i use it together with the mechanical timer?

At the moment the mech timer has 2 periods which switch everything on or off. You can choose HW, HW+CH or off.

How do i wire it up so the old timer just controls HW and new room stat/programmer controls the CH?

 

[dcawkwell]

Been looking at programmers and im a bit confused now.

If i get a digital room stat and use the timer functions for the central heating, how do i use it together with the mechanical timer?

At the moment the mech timer has 2 periods which switch everything on or off. You can choose HW, HW+CH or off.

How do i wire it up so the old timer just controls HW and new room stat/programmer controls the CH?

hw
240volts -> mech timer hot water -> boiler, fires

central heating
240volts -> programmable wall thermostat -> boiler, fires

 

[Graemevw]

But if the hot water is off, and the thermostat fires up for the central heating, wont it heat the water cylinder first?

Maybe im misunderstanding how our system works. I thought the boiler fires and heats the water cylinder. When it gets to the right temp the mech valve opens and diverts the hot water to the rads aswel/instead of through the cylinder.
Is that not right?

At the moment we cant have the heating on without hot water too.