Advice on smart wireless installation

southernlead

Hi,

I'm pretty much sold on picking up the Smart Wireless thermostat. I want to DIY install, but am after some advice before proceeding.

I have a Honeywell ST6400C programmer (controlling central heating and an unvented cylinder), and I think the short story is that I will be replacing this with the wireless receiver. Cool.

However, working alongside the programmer there is a Drayton wireless receiver for a stat in the main living room. This is wired in via a big Honeywell box (pictured)

I'm not really sure I want to go poking around inside there. I don't really know what it is.

The Drayton has a manual override that I can set to "Always On" which I presume is one approach I could take - or is removing the receiver entirely actually a straight forward job?

Happy to open up the Honeywell junction box and send pictures of the wiring if that's helpful.

Thanks for any help!

johnnyp78

If you’re going to remove the Honeywell programmer, I would think you’ll be removing the wiring to the Drayton wireless receiver as well. Have you checked whether your house is zoned - are there any other thermostats upstairs for example? If so it might be more a more complex install.

southernlead

Nope, no more thermostats upstairs.

Here's the current wiring for the Honeywell programmer.

It looks simpler than I had expected to be honest. E, N, L on the left - and then the two wires on the right, which the installer has handily labelled above. Black for HW On, Grey for CH On.

Is this going to map easily to what's inside the wireless receiver?

Do you envisage that I will need to do anything else other than replace the Honeywell programmer with the Tado receiver and then just manually set the Drayton receiver to be Always On?

Thanks for any further advice!

johnnyp78

Bearing in mind you should get custom instructions from Tado when you do the install, it sounds like a standard s plan installation. Have a look at section 4

https://cdn.brandfolder.io/607DGEMS/as/tqh86npbjjhws5gwkxfncbfh/104172-DIGITAL-WRP01IB01-INSTALLER_MANUAL-TA-UK-00-V2.pdf

If the Drayton is still in circuit, leave it set to always on.

southernlead

Thanks johnnyp.

I've ordered the thermostat. Arriving Thursday - looking forward to getting up and running.

SmurfnSurf

Hi,

I was wondering how you got on with that installation southernlead and if anyone here could confirm this would work with a Stanley Brandon AGA Stove which has a Honeywell ST6400C controller like the OP?

Could this be integrated with the two temperature control knobs (does it need to be)?

johnnyp78

One of your temperature control knobs is for oven temp, which Tado definitely wouldn’t work with. It could in theory work for heating and hot water though judging by that installation you seem to have to switch manually between heating and hot water, so you’d need to do some rewiring.

SmurfnSurf

Thanks for that.

We hardly ever use the oven TBH, so if we put in the TADO controller as a drop in replacement and manually adjusted the hot water temperature, would that work for the central heating?

Of course if there was a way to have the (I) Thermostat controlled a swell and (II) that hot water only vs hot water/central heating toggle switch as well that would be great.

The current controller is really just an on/off device with a scheduler as far as I can make out from the ST6400c manual. https://www.manua.ls/honeywell/st6400c/manual

johnnyp78

In theory yes you could. I don’t know enough about how Agas are plumbed in though. Do you have a hot water tank? It’s probably worth getting a professional who’s familiar with Tado in to have a look.

SmurfnSurf

Yup the system is connected to and supplements (AFAIK) an electric hot water cylinder, as well as underfloor and various hot water radiator heaters.

johnnyp78

Sounds like a complicated installation. If it’s an immersion heater cylinder, that can’t be switched by Tado either due to the power demand, so you would need some kind of customised solution.