Wiring honeywell cm 907 thermostat to vokera linea 24 boiler

[tej]

Hi
I have a vokera linea 24 boiler and just purchased a Honeywell cm 907 thermostat. The vokera boiler has an internal timer.
I attempted to install the thermostat and currently have it working but with the internal timer.
So in my boiler I removed the link which was from TA-TA, The internal timer was going into the TA as well. In the thermostat I fed two wires from A and B to the TA. Also I connected a loop wire from A – C which is internal within the thermostat.
But I am stuck as to how I can run the thermostat without using the internal timer? It is battery powered so no Live.
It seems I need to do what the internal timer does but from the diagrams for both the boiler and thermostat it does not seem clear
Please could someone assist
Cheers
tj

 

[jackthom]

Using A & B in the thermostat to feed to the two TA terminals in the boiler sounds OK.

I would remove and tape up both connections to the boiler timer unit so that will leave nothing connected to "=" and only the new thermostat connected to the TA terminals. There should be no links in these terminals.


I don't know why you have a link from A to C in the thermostat so this would be best removed to keep things simple.

(Edit: reading your post again I'm not entirely sure whether you were asking for operational advice or help with wiring. )

 

[tej]

Cheers for the reply. i am asking for wiring advice

There is currently a wire in the "=" but it is green and seems as its a earth.

So once i have eliminated these connections should the thermo work?

should it be wired as the internal timer is wired? cos the timer obviously triggers something to get the boiler going?

cheers

tj

 

[jackthom]

A wire in the "=" shouldn't cause a problem so just leave it.

When the two TA contacts are connected together (via the thermostat) the boiler should fire up for heating.

If the thermostat isn't having any effect you could try a direct wire link from TA to TA to make sure there isn't some other problem with the boiler.

 

[tej]

hi

the TA were both linked via loop before i connected the thermostat.

Just to clarify the boiler does kick in from the thermostat (acts as a basic thermostat) but its the timings that do not work for the thermo. Just the internal timer

 

[jackthom]

If it's working OK as a simple thermostat the CM907 should now just need programming to the times and temperatures you want. It's just a case of going through the setup in the user guide although that does look a little daunting.

I'd be surprised if the internal boiler timer still had any effect now the wiring has been altered.