Help with upgrading Boiler thermostat

[mart7mcfl7]

Hi guys, I've got a vaillant turbomax 828 and the hallway thermostat is a simple two wire affair dial type (VRT 15)

Could a thermostat with the wiring shown be compatible?

 

[ianmcd]

that wiring diagram is for a programmable room thermostat , not a straight swap for a simple thermostat which is what you have , you can fit one but will need rewiring

 

[mart7mcfl7]

that wiring diagram is for a programmable room thermostat , not a straight swap for a simple thermostat which is what you have , you can fit one but will need rewiring

Thanks buddy, I thought as much. I'm just having a look at wiring diagrams to sort it all out.

The connections on the 828 are as shown.

For some reason we don't have the jumper between 3/4 anyway, I can wire a permanent L/N easily enough but it's the call to heat. I'm assuming the stat would be the 3&4 connectors where the stat is an optional jumper. 3/4 is joined to complete the circuit and engage heat?

So connectors 1/2 on my stat (which gives 240v when activated) should be connected to 3/4 on the boiler?

Thanks for the info guys, us Dryliners are a thick bunch lol

 

[ianmcd]

The LNE to your new stat should come from the same fused spur that already feeds your boiler and 1&2 from your programmable stat to 3&4 on your boiler

 

[mart7mcfl7]

The LNE to your new stat should come from the same fused spur that already feeds your boiler and 1&2 from your programmable stat to 3&4 on your boiler

That's what I thought buddy, the only thing that made me scratch my head is that when the call for heat from the old stat is made there is no voltage showing between 3/4 but when heat is called continuity is made.

I didn't want to wire 240 load through 3/4 on the boiler and fry the board.

So permanent fused L/N from the spur to the stat and 'Load (1+2)' from the stat to 3/4 on the boiler, seems simple enough.

 

[mart7mcfl7]

Oh, and for some reason? There is a switched live running with the stat wires, not connected to anything and left open (not protected) and that wire ranges from 30v to 240v when call for heat is made.

 

[mart7mcfl7]

All sorted guys, only had to setup LN and only had to connect 1 from the stat to 4 on the boiler.

Job done