grant oil boiler

[Rob69]

Hi All,

A Grant vortex 26e combi boiler has been installed and i need to connect a timer unit into it to control the central heating.

I have got two terminals to connect into labelled " timer live " and " timer neutral " for this purpose i believe.

The timer unit has a normally " closed " or normally "open " position choice on wiring. Am i correct in saying the live and neutral to the boiler terminals connect to the normally open position at the timer unit.

The timer unit is a honeywell 111 unit that is being supplied.

With thanks

Rob

 

[Rob69]

Sorry not a honeywell timer its a LT111 cant remember the maker though!!!!

Thanks rob

 

[sparkytim]

Combi boilers need a permanant supply to them and then if you are fitting an EXTERNAL timer it needs to provide a switching circuit to a pair of connections in the boiler marked EXTERNAL CONTROLS or Thermostat.

It usually has a link that is removed and replaced by a 2 core cable from your new Timer that need to be VOLT FREE contacts.

Your timer will need a permanant supply to power the clock, but this should NOT be interconnected with the pair of conductors coming form the boiler to switch in the heating

You also should have a Room thermostat in the circuit to comply with Building regulations, this is wired in series with the timer.

The boiler installation manual should explain all this

PS This is notifiable work

 

[Rob69]

Hi sparky,

What do you mean by "volt free contacts"?

I understand that you mean the timer unit with internal relay switch is just connected via thermostat straight into boiler terminals and the boiler circuit detects the switch being closed itself?????

Hope that makes sense!!!

Cheers Rob

 

[Rob69]

Also,

According to the building regs where is best place to site the thermostat in a house?????

Plumber said to client that thermostat was not needed......oh dear!!

Cheers Rob

 

[batty]

Also,According to the building regs where is best place to site the thermostat in a house?????

Plumber said to client that thermostat was not needed......oh dear!!

Cheers Rob

I hate it when there is no roomstat its impossible to test system.

 

[sparkytim]

Hi again

Volt free contacts mean that the Timer power circuit that runs the timer clock is independant to the circuit that it operates.

Not all programmers have this option.

The problem is that some Combi boilers control wiring is EXTRA LoW voltage.

So if you wire them thru a timer which switches 230 volts back to the boiler on the switching circuit it will not do it much good.

The room thermostat can go anywhere, as long as its not near to a radiator or in a drafty spot.

Some like it in the Hallway, some in the lounge.

If you go for a wireless type this can be "mobile" and moved around to find the best spot.

Boiler controls are not as staight forward as many thinks and as mentioned earlier are Part P notifiable work, are you registered ?

 

[Rob69]

Hi Sparky,

Thanks for your post!!!!!

I have got all relevent certificates but until i can afford to "register" i am using local building control.

Cheers again