Smart Thermostats

[Jobbo]

Can you post a photo of the boiler end wiring, Duncs? It may be that it's integrated into a panel on the front of the boiler in which case you probably ought to get a gas safe engineer out to change it, but if it's a separate unit mounted to the wall it should be a piece of cake to change. There are not many wires.

[jamcg]

Right guys, after a bit of procrastination I need to get this sorted. This is what my thermostat looks like inside and out, can I not just wire in a new smart thermostat here rather than mucking about with wiring it up at the boiler? As long as it doesn't click, I don't mind it being in the bedroom.

Your controller is a simple live in/ live out with a battery powered relay. The wiring at the boiler end (assume combi) will be wired directly into the boiler. Depending on the boiler to access the wiring you may need to remove the boiler casing, which could also be a combustion chamber seal so you should be qualified to remove that case.

[duncs500]

Right guys, after a bit of procrastination I need to get this sorted. This is what my thermostat looks like inside and out, can I not just wire in a new smart thermostat here rather than mucking about with wiring it up at the boiler? As long as it doesn't click, I don't mind it being in the bedroom.

Your controller is a simple live in/ live out with a battery powered relay. The wiring at the boiler end (assume combi) will be wired directly into the boiler. Depending on the boiler to access the wiring you may need to remove the boiler casing, which could also be a combustion chamber seal so you should be qualified to remove that case.

Boiler is a Worcester Greenstar 36cdi combi, the wiring is behind a panel.

So assuming the boiler end is a PITA, the question still remains can I just put a new thermostat on this end?

[Jobbo]

Your controller is a simple live in/ live out with a battery powered relay. The wiring at the boiler end (assume combi) will be wired directly into the boiler. Depending on the boiler to access the wiring you may need to remove the boiler casing, which could also be a combustion chamber seal so you should be qualified to remove that case.

I'm wondering if Duncs could replace the existing mount with a standard mount and put something like a Drayton Wiser controller on there with remote thermostat? Would be a shame to have a wall-mounted control box in the bedroom so it's not the ideal way to do it, but it should be possible to my (DIY) eyes. I'm not sure if the black, brown and grey wires may indicate that it's not though.

[McSwede]

If that's a controller and thermostat shirley you can wire a smart receiver there and put a thermostat/controller wherever you want.

We've used Tado on the rentals in similar replacements.

This. I have Netatmo stuff and it's brilliant

[jamcg]

Problem you’ll have wiring something into there is the lack of a neutral. You’ve got permanent live in and switch live back out currently wired into the thermostat terminals. If that choccy blocked wire is a neutral and is still connected then happy days, you can just wire any receiver up to it

At the boiler end a Worcester cdi case is a gas sealing case so you can’t remove it. However if you can identify the wire that’s heading off to that thermostat you could cut it, utilise that for the switch live side of a receiver and then pick up permanent live neutral and earth from the boiler thermostat

[duncs500]

If that choccy blocked wire is a neutral and is still connected then happy days, you can just wire any receiver up to it

How to I figure out if that is a connected neutral? I'm guessing they would have had no reason to connect it if they didn't need it for the system?

[duncs500]

Sure I can't take a peek at the connections? It's literally three screws and tells you how to do it on the front...

[jamcg]

Ah now that’s not just a cdi, that’s a cdi compact. That boiler you can go into the connections without breaking a gas seal.

This is what the connections look like, just wire in your smart receiver box like this direct to the boiler and attach it to the wall somewhere convenient

IMG_0812.png (67.29 KiB) Viewed 499 times

[duncs500]

Ah ha! Sorry, should have given it the full title. Sweet, I'll give it a go. Wish me luck!

[Mito Man]

[jamcg]

Ah, the moment on the news that every gas engineer shits themselves in case it’s a house they’ve worked in

[duncs500]

Well, gave it a go today but not got it right so far. I installed it all ok, and it's all paired up, fires up the boiler fine etc. But the radiators don't warm up.

I was kinda expecting one cable in and another cable out to the thermostat, but I've only got one cable in with three cores going to the power and one core to the central heating terminal.



Although the cable in question goes into the wall, I did notice that tucked up above the boiler there is a Timeguard junction box that has a wire to a valve. So my uneducated guess is that this box has various wires from the upstairs thermostat along with the underfloor heating stuff. This then both powers the boiler, calls for heat, and opens a valve? Is that possible?

Could I just keep both cables going into the CH LR terminal? Because if the old wired thermostat is disconnected it won't call for heat, but the other stuff on the JB still can as well as the smart thermostat link. This may possibly also make something explode! @jamcg thoughts?

[duncs500]

Ah, a bit of research tells me that the switching needs to go through the valve first. That's annoying, so I've got to get up to that JB, which is buried under some panels.

[jamcg]

You’ve saved me answering your question as soon as you have zones and underfloor heating etc the wiring does get a little more complicated

[duncs500]

I've got a pretty good idea how it should look inside the JB, so I'll open it up and see. If it's too confusing I'll give up.

[jamcg]

I've got a pretty good idea how it should look inside the JB, so I'll open it up and see. If it's too confusing I'll give up.

Find the wire going to the radiator zone valve. Follow it into the junction box. Disconnect control wire connected to the zone valve brown wire (from all terminals). Connect new wire to LNE and then the feed back into the system (aka call for heat) to the brown zone valve wire.

[mik]

Find the wire going to the radiator zone valve. Follow it into the junction box. Disconnect control wire connected to the zone valve brown wire (from all terminals). Connect new wire to LNE and then the feed back into the system (aka call for heat) to the brown zone valve wire.

[duncs500]