Central Heating Controller - Touchscreen, Wired

RomfordNavy

A bit basic but found that a Honeywell T4 can have a remote wired temperature sensor.

Admittedly not a great step forward as it doesn't support OpenTherm or Vaillant eBus, and it is of course Honeywell which I would rather have avoided but if that is all I can find then maybe that is the best solution.

BUFF

There is a version of the T4, the T4M, which supports OpenTherm but then you are back to the issue of additionally needing the OpenTherm module to enable it to communicate at bus level with your Vaillant & by then my opinion is that you might as well get the Vaillant control ...

You could probably expect to get ~5% energy saving (it will of course vary from installation to installation) by having advanced modulation so you ought to be able to calculate annual saving in £s & therefore how long it would take for that to move into profit re. just buying & installing the cheaper but less sophisticated  system.

RomfordNavy

BUFF said:

There is a version of the T4, the T4M, which supports OpenTherm but then you are back to the issue of additionally needing the OpenTherm module to enable it to communicate at bus level with your Vaillant & by then my opinion is that you might as well get the Vaillant control ...

You could probably expect to get ~5% energy saving (it will of course vary from installation to installation) by having advanced modulation so you ought to be able to calculate annual saving in £s & therefore how long it would take for that to move into profit re. just buying & installing the cheaper but less sophisticated  system.

Looking good; the Honeywell T4M (T4H310A3032) can be paired with the wired Remote Sensor (F42010972001) and used with the VR33 opentherm board that you suggested.

However now looking into whethetr the T6 can be used with a remote sensor; there is some suggestion that a C7189U1005 wired temperature sensor should wotk with a T6 but so far have been unable to confirm if the UK T6 has the connections for this.

RomfordNavy

It seems that there is only one version of the T6 wired (Y6H910WF1011) which can also be paired with that Remote Sensor (F42010972 001) and openTherm compatible with the extra VR33 module.  This particular T6 is apparently now discontinued but a number of suppliers still seem to have stock.  Also wireless signal can be turned off if required.

So there is a choice of a T4M or T6 wired with touchscreen.  Apart from that the main difference I can see is that the T6 has this seperate 'Receiver' module which also needs to be wired in, I wonder if that is necessary if I am not using wireless?

Do you know if either of these can be powered from the boiler or whether they are battery powered only?

RomfordNavy

Further problems: I had intended to install this in on/off mode firstly to ensure it works properly with the remote thermostat and then add the openTherm interface afterwards.  However I now find that the T4M is openTherm _Only_, it does not have A/B connections for on/off mode.  Looks like the T6 Wired does support both on/off mode and openTherm but I can't find a full wiring diagram anywhere showing how to wire the Receiver unit to the display unit.

RomfordNavy

Any thoughts on whether an External Temperature Sensor (F42010971-001) could be used in place of the Indoor Temperature Sensor (F42010972-001)?  Anyone know if they both use the same thermistor?

RomfordNavy

@Buff thanks for your suggestions here.  Have now got a T6 Wired (Y6H910WF1011) working with an external temperature sensor (F42010971-001) but mounted internally in another room.  This is so much smaller and less obtrusinve than the internal sensor, just a small 1/2" black sensor sticking out of a door frame.  All working fine, in fact I am very impressed an how easy the Touchscreen interface is to use.  The "Smart" controller appears to have learn't about the thermal characteristics of the house and now seemingly only 0.5deg change from on/off so holding a very stable temperature, impressed.

Will let it run for a few weeks before thinking about the Opentherm interface.