Hive Active Heating Thermostat Installation

[faz]

I'm installing a Hive Active Heating Thermostat at my parents, however I'm confused with the current installation of the old wired programmer and thermostat. They have a Vaillant ecoTEC plus 418 conventional boiler installed in the garage with a programmer in the kitchen and thermostat in the hallway. However when opening up the boiler to install the Hive receiver I can't see where the programmer connects to the boiler. The boiler only appears to have a 3-core flex entering with mains (see white cable bottom left of image in following link: https://ibb.co/vmYPHFR) but no signal from the programmer/thermostat. I expected to see an additional core connected to the 'RT' terminal next to the mains.

Does anyone have any suggestions how the current wired programmer and thermostat is controlling the boiler and how I go about removing these to install the Hive receiver?

 

[Doc Hudson]

As there are no standard colours for central heating wiring. we really need a drawing/description of how it was originally wired between programmer/thermostats etc.

Doc H.

 

[faz]

Thanks Doc, hopefully the wiring diagram in the following link helps understand the installation (https://ibb.co/FsHCGSG).

I'm confused as I assumed that the cable indicated in the diagram (3 core flex with Red, Blue & Yellow - labelled "Cable going to boiler??") would go off to the boiler. However, I when I open up the boiler there is only a mains supply Live, Neutral and Earth (i.e. no signal from the thermostat). How is the boiler being controlled by the thermostat and programmer. And ultimately, how do I install the Hive Thermostat in this setup?

Many thanks

 

[kerching]

No idea without a lot more info

how have you come up with that drawing if you don't know where the wires go....or am I missing something obvious?

worked on one a few weeks ago where the home owner had wired every terminal,with two wires....one in one out, both going back to same place. His theory was that the electricity has to get back!

i walked  :coat

not my monkeys, not my circus

 

[Geoff1946]

There must be a "wiring centre", (posh name for a junction box, used by heating installers), where all the connections for the existing controls come together with the power input and the output to the boiler, probably motorised valve, and pump.   Be warned, it can get complicated and I think you may be better calling someone in if you are out of your depth.

 

[Doc Hudson]

Thanks Doc, hopefully the wiring diagram in the following link helps understand the installation (https://ibb.co/FsHCGSG).

If that drawing is how your current system is actually wired then I cannot see how the current thermostat has ever worked?  Ignore the colours for the moment, if you try to follow a live path from the programmer, via thermostat to boiler, its just looping back round on itself doping nothing!.

Doc H.

 

[ProDave]

If that drawing is how your current system is actually wired then I cannot see how the current thermostat has ever worked?  Ignore the colours for the moment, if you try to follow a live path from the programmer, via thermostat to boiler, its just looping back round on itself doping nothing!.

Doc H.

I suspect the drawing is wrong, but if he has got the thermostat connections confused, it's possible to see a situation where the yellow core to the boiler is switched L when the timer and thermostat call for heat.

That doesn't help solve the question until we get an accurate drawing.