Hub Controller options

That's a wireless kit, the powered receiver sits in place of the Hub, the wireless stat can be located anywhere in your preferred room. Little bit more to the wiring, neutral is used, and a link inserted from L live to CH Com. The V1 wire from the Hub goes to CH NO. Theres a Hot Water relay you won't need, so ignore, but with additional wiring it could be used for HW only switching.

I second your comments @deezell is a mine of information and as important is willing to share it.

For anyone here who ended up getting the tado system mentioned, I found a free year of the smart assist thing they have in the app. And it's paid by Google play, so it's simple to cancel later

Offer was just there when I opened app

Go to page one, read posts from 1-12-2022, wiring of the wireless receiver and stat. The wired one is even simpler to DIY. Check screwfix or Tado for starter kit prices, but this is a steal for wall stat, wireless receiver and Internet bridge device.

https://www.screwfix.ie/p/tado-v3-wireless-heating-hot-water-smart-thermostat-starter-kit-white/141kt

The bridge connects to the router by axshirr supplied ethernet cable, no messing with WiFi. The wall stat and receiver communicate with each other and the bridge using a low power wireless protocol call 6LoWpan, similar to zigbee but not visible to it. However, the stat is discoverable on Alexa, HA, Google, Home kit, but not on IFTTT.

I was telling my buddy about the tado system I replaced my parent's hub controller with and he was saying he'd like something similar, but would prefer a system that let's you just schedule heating on or off like the hub (not like the tado which is more based on target temperatures). He said his boiler is a condensor and they don't have a water tank, the hot water comes direct from the taps through the boiler.

Any idea if there's an alternative drop in replacement for the hub that is more based on scheduling the heating on and off? I said I'd ask here for him anyway...

Oh I get you, I prefer just set and forget with the tado, but that's what he asked for. I guess just old fashioned and used to what he's used to?

Hi all, have my system set up as above with

Neutral blue in place

Live in place looping to ch com and hw no

Pump connected to ch no and hw nc but ch no and hw nc not connected ie seperate feed wires from pump

Boiler switch live connected to hw com

Everytime the system calls for hot water, it starts the ch pump, any thoughts on what I'm doing wrong?

Hi Deezell, it's as per the drawing you put up on 23 Feb 23, gravity fed system

Great, I'll have a look back 2 years! I'll be back. 🤖

It looks correct except for the two red. There should be a single wire to the pump which activates it, which in an older gravity system would have been the live back from a mechanical room stat to turn on the pump. The wiring diagram I posted was a method of wiring a volt free two channel controller in gravity mode, whereby any call from either the HW relay or the CH relay would supply a boiler live on the HW terminal only, as this is the only connection to the boiler. HW will be heated for either call, but a CH call only will divert CH live to fire the boiler via the HW No terminal, at the same time activating the pump for CH flow. I'm unsure if the two red wires on your setup are joined, and if they are connected to the circulation pump live only.

This wiring was useful for two zone controllers with a 2 pole relay per zone (No and Nc), which didn't have a gravity mode switch or soft configuration. The Nest two zone receiver was one example, there were other two zone controllers with a similar shortcoming, and when Tado introduced that newer extension kit with similar volt free 2 pole relays, the mode switch for gravity was eliminated. However, since I posted the bodge a few years ago, I've discovered that the new Tado ext kit can be soft programmed to enable gravity mode. In this mode the wiring is simple. Links from live to both CH Com and HW Com. CH No to the pump (or zone valve), and HW No to fire the boiler. Any CH or HW timed event will fire the boiler via terminal HW No, but CH will not happen unless the CH No terminal to the pump goes live. The ext. kit is configured to gravity mode by holding down the two top right buttons for 5 seconds, then press the heating test butto until the power light goes Blue.

Try and establish exactly how your system is operated. With only a HW live to the black boiler wire, all others off, does the pump still operate. Check those red wires again. There has to be a single source of power to a pump or a zone valve in gravity system, thats allows CH flow, while HW will heat for either CH, HW timings or both at the same time

With the receiver configured for Gravity mode, all the linking of the other diagram is done internally. Boiler will fire when either CH or HW is ON, via the HW No terminal

Pump will operate only when CH is on, via the CH No terminal. Again, I'm assuming this is the circulation pump to the radiators.

If your boiler is a gas boiler with an internal pump, then this pump will always pump to the radiators when the boiler is fired, so such a Gravity system requires a motorised zone Valve opened only by the CH No terminal when CH is on, and off when only 'gravity' heating of HW is on, though this will now be pumped flow to the HW cylinder.

Is your boiler oll or gas. It sounds very much like you either have a boiler with and internal pump, or else the boiler was wired back to the circulation pump so that it always pumps when firing. What was your previous setup. Maybe you posted this back in 2003, but there's no easy search on boards anymore. Had you an old wall thermostat for CH? If this still there and controlling the pump, and is turned up, it may be supplying live to the pump from the boiler SL, switched live. Disconnect the red wire, and see does the pump and CH operate If the boiler is fired.

Im not sure buddy, but I disconnected old stat and can't see any change whether pump is on or off so maybe the stat is just a motorised valve

I've just disconnected the stat today, and joined the wires to see what happens/ try get pump to fire