wiring help on old Ideal mexico boiler?

[liddley]

Can any one advise me on adding a new roomstat and programmer to the above boiler.
I have limited no how when it comes to central heating controls so here goes!

I have been asked if I can add a new room thermostat and a programmer to an old ideal mexico cf40 boiler.
At the moment all the system seems to comprise of is power to the boiler itself via a switch fuse spur and what looks like a kettle plug which just plugs into the boiler to power it up. Then a 3core and earth from the same spur to a room stat which returns to a joint box and powers a Grundfos pump which i think controls the rads?
I can not see what regulates the hot water as I can not see a tank stat on the cylinder or where it would connect to the system?
Can not see what fires the boiler off,does it need a line and neutral at all times feeding it or is this what makes it fire. Was worried if i drop the power to the boiler the pilot light may go out and it will need relighting?
Any one any ideas?

 

[snowhead]

There won't be a tank stat, the water is gravity circulation (boiler on, no pump needed).
Pilot light doesn't need any power to keep it on.

At the moment it will work as follows;
Turn on the spur, boiler will fire, hot water will gravity to tank untill the boiler stat is happy and the boiler switches off, (boiler stat determines Hot water temp)

Then with the spur still on, if the room stat is turned up the pump will start to cool down the boiler, which will fire up and allow the pump to heat up the Rads.
When the room stat is satisfied the pump will be switched off, the boiler will stay on until the boiler stat is happy and switches it off.

 

[JD Hogg]

See if you can get hold of the manufacturers instructions; they may be available on line. If that doesn't help try asking this question on the Plumbers Forum.

 

[liddley]

Thanks for that, I was not sure what fired the boiler off. Was worried that if I powered it down the gas valve would shut it all off completely. I have found some destructions online but only seem to have wiring diagram for Y and S plan. But surely all that's needed is the boiler supply to be switched buy a single channel programmer and also the room stat for heating?