bridging old thermostat hive

[nextcontestant]

im sure this has been posted a million times already but just after some advise

iv installed hive its all working connected but i have disconnected my old thermostat but hive isn't communicating with my boiler so my boiler inst coming on when i want heating.

i have been doing a little research and it seems i need to bridge the contention where my old thermostat was connected.

iv added some pics to show what iv done if some one can advise what wires i need to bridge that would be great thank you

 

[stem]

The old wired thermostat can't simply be disconnected as this would leave the heating wiring 'open circuit' and the heating will not operate. Here's how to decommission the old thermostat properly.

1) Trace the thermostat cable from the thermostat back to find its origin.
2) Make a note where the wires from the thermostat cable are connected, then disconnect all of the wires and remove the cable.
3) Add a wire to link the two terminals where the Red and Yellow thermostat wires previously originated from so that they are electrically connected.

 

[nextcontestant]

thank you so much that's all i needed to know was what color wires i needed to bridge together, i know where they go back to in the power block see pic

 

[ericmark]

I have found problems in working out what wire does what in a junction box as you show, however the motorised valve has standard colours so that is a good point to start with. Blue = neutral, green/yellow = earth, white = room thermostat, grey = cylinder thermostat, orange = pump and boiler so it seems you have identified the white.

I have not seen a Y plan in ages, so a little green now, however I do remember trying to repair my daughters some 12 years ago and I found the motorised valve is not actually as the plan shows it, my plan showed one micro switch and in fact there were three, so all my testing was producing results which did not seem to fit to the plan.

You show a yellow connecting to white which seems likely the thermostat connecting to motorised valve so I would suspect that cable comes from the thermostat, so it is likely that cable which needs disconnecting and linking.

Personally I agree with Stem my electronic TRV heads can be set remotely with the phone, last week I went on holiday over 100 miles away for 6 days so I could have turned off the heating for two main rooms and then back on again before return, but I forgot, and other than that the house takes two long to heat up to be worth turning off. It is not boiler too small, it is the anti-hysteresis software in the thermostat and electronic heads on the TRV which causes the problem, it will heat from 5°C to 17°C really fast, but from 17°C to 20°C it is really slow.

 

[stem]

I have found problems in working out what wire does what in a junction box as you show,

The problem is, that no two are the same. Sometimes an OP will show a photo of their wiring centre and expect us to know exactly what every wire does. The motorised valve does give a start in the case of a Y Plan, but if it's an S plan there are two identical valves each wired to a thermostat, so impossible to know which is which just from the wiring. Other times the room stat is wired directly to the programmer and doesn't come into the wiring centre at all. Add to that green / yellow wires, or blue wires used as a live, without any identification.........and the thing I can't work out, is why are the wiring centre photos posted on here such a diabolical mess, rarely are the cable clamps used and you can never follow any of the wires from the photo because it resembles a rats nest.

 

[ericmark]

I have seen adverts for wiring centres, but what I find is a double socket back box, some 5 amp connector strip, and a blanking plate. At lest this one has cable clamps.

But can't really understand the use of Hive. OK Nest will connect to electronic heads on TRV's and is opentherm enabled so yes can see why Nest is used, but Hive has so little going for it.