Smart thermostat installation sticking point [images]

[mikeduk]

Hi all,

Last weekend I attempted to fit a 'self install' smart thermostat at my Mum's house, which is a job I've done once successfully before.

Everything was going well until it came to fitting the wires from both the existing power to the boiler, and the smart thermostat's wires into the same port's on the terminal block. The ends of the flex wires had ferrules on them, and after about an hour of messing around I managed to get the brown live wires into the port to an acceptable extent (that's after repeatedly crimping the ends into all types of shapes).

No matter what I tried I couldn't get the blue neutral wires into the block fully, so I had to abort the job, I would of had trouble being completely comfortable that everything was safe.

If I remember correctly, the last time I did one of these, it was an old boiler and the wires didn't have ferrules on them. I just twisted them together and fed them into the ports.

Would it be possible for someone to suggest the best way to solve this problem? I've been quoted £180 for a heating engineer to install, but I feel like it deserves another shot after spending 3-4 hours messing around with it last week.

Here's some images to give further context:

Before install (there's not a huge amount of room to work in):

The extent I managed to fit live and neutral wires:

The thermostat came with these parts, but I couldn't work out how I'd utilise them, or if there would even be enough room to make something like that work:

Appreciate the help.

 

[BS3036]

If it were me I'd cut the ferrules off.

 

[mikeduk]

If it were me I'd cut the ferrules off.

I did consider this, but I don't currently own the tool to strip a new section of each wire, that's something I could buy though.

Is it completely safe taking the approach of twisting the wires together and then inserting into the ports?

I was also worried this existing earth wire here might have too much of it's copper showing. So maybe I need to re-strip that cable too?:

 

[CountryFan]

If there’s slack/play on the flex, it would be better to make the earth wire more slack as it seems tight and shouldn’t be the last to pull out if the cable comes out.

 

[ericmark]

I also found the hubs for the thermostats tight, so I used a wiring centre between them so only a single wire into each terminal, and also had a problem with ferrules, the pliers for them were too shiny and someone decided they wanted them, only replaced this year from Lidi, at last again I can fit new ferrules.

The main problem is we try to use the hub as a wiring centre, and there simply is not enough room, putting a socket box behind the hub can help, some hubs like the Wiser fit on a frame, which has centres for screws which match a back box, but near impossible to test, as need to remove hub to access wires, where the Nest Gen 3 I can remove cover and test with hub still connected.

The problem without the ferrule, is a strand of wire can get into the screw and bind it, so you think it is torqued up, but it's not, one reason for not using a torque screwdriver, they remove the feel, the old method was to tin the wire with solder, but if we re-torque terminals on a service, this can cause the wire to neck off, but I have not seen house wiring serviced, we would with the likes of a batching plant for making concrete as on a steel frame, and vibrations could cause terminals to become loose, but not found this a problem with a house, which asks the question, of why use maintenance free terminals?

 

[Harry Bloomfield]

I did consider this, but I don't currently own the tool to strip a new section of each wire, that's something I could buy though.

Tool? Practice stripping a piece of scrap cable, with the cutters, of a pair of pliers, to get the knack. You just squeeze enough to grip and tear the insulation, without damaging the copper inside.

 

[Taylortwocities]

I did consider this, but I don't currently own the tool to strip a new section of each wire, that's something I could buy though.

I'm sorry to be hard on you, but - if you are doing any job - you need to have at least some basic tools....

You could try with a pair of scissors and a sharp knife but really, for a couple of quid at your local Robert Dyas will get you a pair of cutters and maybe a screwdriver too?

Tool? Practice stripping a piece of scrap cable, with the cutters, of a pair of pliers, to get the knack. You just squeeze enough to grip and tear the insulation, without damaging the copper inside.

 

[ericmark]

I did my central heating in the summer, so loads of time to correct any problems, be it a larger connection block, or tools, in your case likely a junction box next to the boiler so only a single core into each connector in the boiler.

I had the same thermostat end, they call the junction box a wiring centre, seen here between the two hubs and a thermostat, it gives one the room you need.

The Nest Gen 3 on top, was very tight for space, that went in first, not a success so added Drayton Wiser to right, the mechanical thermostat only does the flat rarely used in winter. It did look like this when I moved in, seems last occupants went off with the wireless thermostat, so that base was useless.