Smart Thermostat recommendations?

BlueLoo · 7 Jan 2022

oldbutnotdead said:
The Opentherm module in the 3 channel only triggers the boiler if there is demand on heating channel 1, it ignores demand on heating channel 2. I also don't know for certain that the module is actually sending Opentherm signals to the boiler...it may just be closing the circuit.
The optimisation on the Wiser is pretty good.

Are you sure about this?

The hub control setting for relay/load comp/open therm is global.
There is no hierarchy, or zone assignment.

BlueLoo · 7 Jan 2022

oldbutnotdead said:
The Opentherm module in the 3 channel only triggers the boiler if there is demand on heating channel 1, it ignores demand on heating channel 2. I also don't know for certain that the module is actually sending Opentherm signals to the boiler...it may just be closing the circuit.
The optimisation on the Wiser is pretty good.

Are you sure about this?

The hub control setting for relay/load comp/open therm is global.
There is no hierarchy, or zone assignment.

BlueLoo · 7 Jan 2022

vulcancontinental said:
Well most will do what you want which is simple switching from several sources. Guys I know rate Honeywell and you get personal support from the evohome shop but I'm told it can be tricky to set up so buy from somewhere you'll get support rather than just sell you a product.

Heard good things about Wiser, know no more than that. Tado has dropped support for bus control (slight improvement in efficiency) but will do the job.

You're right to think about boiler brand and working with controls but if you're not going bus control you can swap as you like.

Personally I have bus control with weather compensation, normal but good quality TRV's in all rooms except the room with the main thermostat. Does it work well? Certainly does but if you asked me does it work significantly better than anything else I'd mention it's officially reckoned to be a 4% improvement in efficiency (I think more) but I use it to monitor the boiler remotely not to control the heating remotely. Myself I have no need to control the system from somewhere else and am puzzled by people who do but they undoubtedly exist in great numbers.

I find my recent switch from the old 1980's-esque 2 zone, electro-mechanical (TRV/Timer) system to a modern zero zone, app controlled system (Wiser) to be a revelation. More importantly, my family have got on board with next to no fuss at all.

Smart controls can save money and increase efficiency, but if you have any system well set up regardless, then perhaps those savings may not be significant. However, my heating is MUCH more consistent, comfortable and user controllable.

oldbutnotdead · 7 Jan 2022

BlueLoo said:
Are you sure about this?

The hub control setting for relay/load comp/open therm is global.
There is no hierarchy, or zone assignment.

Yes. In the mfrs instructions it says Opentherm is not enabled for the 3 channel.
From observation, WiFi rad stat on heating #1 calls for heat- relay in hub clicks, boiler fires (only connection from hub to boiler is the Opentherm pair).
WiFi rad stat on heating #2 calls for heat- relay clicks in hub, boiler does not fire.Move rad stat to #1- relays click, boiler fires.

BlueLoo · 7 Jan 2022

oldbutnotdead said:
Yes. In the mfrs instructions it says Opentherm is not enabled for the 3 channel.
From observation, WiFi rad stat on heating #1 calls for heat- relay in hub clicks, boiler fires (only connection from hub to boiler is the Opentherm pair).
WiFi rad stat on heating #2 calls for heat- relay clicks in hub, boiler does not fire.Move rad stat to #1- relays click, boiler fires.

Channel 3 is hot water, not CH?

Friday round · 7 Jan 2022

IMHO ensure there is an auto bypass installed onto the system, put in TRVs in all the rads. For the bathrooms, put in smart TRVs with boost capability. This will allow you to heat only your towel radiator on demand during heating off seasons.

I have a Wiser controlled system and I chose it because it was cheaper than the others. It’s adequate, very accurate, but app features like usable geofencing is lacking and support/docs is missing info thus the side chat above.

vulcancontinental · 7 Jan 2022

BlueLoo said:
I find my recent switch from the old 1980's-esque 2 zone, electro-mechanical (TRV/Timer) system to a modern zero zone, app controlled system (Wiser) to be a revelation. More importantly, my family have got on board with next to no fuss at all.

Smart controls can save money and increase efficiency, but if you have any system well set up regardless, then perhaps those savings may not be significant. However, my heating is MUCH more consistent, comfortable and user controllable.

Yes, it all depends on where your start point is. Time hasn't changed so that will be a constant but now the thermostats are digital and even though they may have no bus control the software can smooth out the fluctuations and help with boiler cycling. Comfort is the target and if you're hitting it that's a 10/10.

Things do not have to be perfect though and I smile at thermostats that can be set to 0.2 or 0.5 of a degree increments but they have to be better than the old style with a hysteresis of at least 2 degrees above and below, often more. The human body is not particularly sensitive to heat in the one to four degree margin with slow changes unless there is a passage of air across the skin.

oldbutnotdead · 7 Jan 2022

BlueLoo said:
Channel 3 is hot water, not CH?

Yeah, 3rd channel is hot water, you can't control it with the WiFi rad valves or the WiFi thermostats so don't go thinking it gives you 3 channels of heat, it doesn't.

floob · 7 Jan 2022

oldbutnotdead said:
The Opentherm module in the 3 channel only triggers the boiler if there is demand on heating channel 1, it ignores demand on heating channel 2. I also don't know for certain that the module is actually sending Opentherm signals to the boiler...it may just be closing the circuit.
The optimisation on the Wiser is pretty good.

@floob Your half and half idea of control won't work. Consider- you have your sitting room with WiFi rad valves, dining room with ordinary trv. You want sitting room warm- fine, valves set to temp and call for heat. The dining room is going to heat on the same schedule as the sitting room.
Only by going full controllable heads can you have an individual schedule (temperature and time) for individual rooms.
You also have to watch system efficiency- if only 1 rad is calling for heat and that rad is quite small (below the bottom range of your boilers modulation capability) then you may get into boiler cycling.
From a comfort pov, you may find that you want to leave the hallway (and bathroom) rads on conventional TRVs rather than smart ones to keep some background heat in those spaces- also avoids cycling and low efficiency probs as above.

Hi,

I was thinking a TRV in all bedrooms and lounge, then normal ones in hall and kitchen set pretty low, and normal ones in bathroom towel rails set a bit higher?
The 2 rads in the lounge could report to a single wireless thermostat to set the tempature that way? At least thats how Tado imply it will work with multi rads in 1 room.

floob · 7 Jan 2022

vulcancontinental said:
Well most will do what you want which is simple switching from several sources. Guys I know rate Honeywell and you get personal support from the evohome shop but I'm told it can be tricky to set up so buy from somewhere you'll get support rather than just sell you a product.

Heard good things about Wiser, know no more than that. Tado has dropped support for bus control (slight improvement in efficiency) but will do the job.

You're right to think about boiler brand and working with controls but if you're not going bus control you can swap as you like.

Personally I have bus control with weather compensation, normal but good quality TRV's in all rooms except the room with the main thermostat. Does it work well? Certainly does but if you asked me does it work significantly better than anything else I'd mention it's officially reckoned to be a 4% improvement in efficiency (I think more) but I use it to monitor the boiler remotely not to control the heating remotely. Myself I have no need to control the system from somewhere else and am puzzled by people who do but they undoubtedly exist in great numbers.

Thanks for the info. Stupid question, but what is "bus control".
Is this related to relay on/off and modulation?

Tado have said:
==============
"With traditional heating systems, a simple relay is used to turn the boiler on or off. When the boiler is on, it heats water to the preset temperature until the thermostat tells it to turn off. The result is often that your radiators come on full blast and can often overshoot the temperature you set. As a result, the thermostat waits until the temperature falls then kicks the boiler into maximum gear again. The average temperature you achieve may be right, but you end up over and undershooting the level you set, which isn’t ideal.

A digital interface allows your smart thermostat to change the temperature of the water used for the heating. This is called modulation. As most smart thermostats understand how long your home takes to warm up, they can measure the heat required to get your house up to temperature. From that, they can set the boiler to the most efficient water temperature to achieve the goal. In many cases, thermostats may set your water temperature to a lower level, using longer heating times to hit the set temperature. With a modern condensing boiler, running at lower temperatures for longer can be more efficient, saving you more energy.

Furthermore, regarding the compatibility with tado°, please find more information in the following article.

· Is tado° compatible with my boiler?

However, in order to confirm compatibility with your boiler, please contact us with the exact model name of your boiler."
=================

floob · 7 Jan 2022

Schrayder said:
This guy has a decent video on "smart" heating controls.

Thanks for this.
He says at 08:58 that Tado can simulate any boiler bus language, but someone also said they dont that any more. Its right that Tado supports Opentherm on combis?

BlueLoo · 7 Jan 2022

oldbutnotdead said:
Yeah, 3rd channel is hot water, you can't control it with the WiFi rad valves or the WiFi thermostats so don't go thinking it gives you 3 channels of heat, it doesn't.

Why would you?

Where on earth do you want 3 channel of heat?

You only ever want two. One for CH and one for HW.
You simply zero zone the system.

I don't need the three channels. I only use the two. Should have just bought a 2 zone controller tbh.

I think you are still thinking in Honeywell xyz plan mode.

BlueLoo · 7 Jan 2022

floob said:
Hi,

I was thinking a TRV in all bedrooms and lounge, then normal ones in hall and kitchen set pretty low, and normal ones in bathroom towel rails set a bit higher?
The 2 rads in the lounge could report to a single wireless thermostat to set the tempature that way? At least thats how Tado imply it will work with multi rads in 1 room.

Just put smart valves on all rads.

If you going smart, don't do it half arsed.

Schrayder · 8 Jan 2022

floob said:
Thanks for this.
He says at 08:58 that Tado can simulate any boiler bus language, but someone also said they dont that any more. Its right that Tado supports Opentherm on combis?

I think that is correct that tado no longer suppots open therm.
Most interesting to me is his recommendation of manufacturers own controls.

oldbutnotdead · 8 Jan 2022

floob said:
Hi,

I was thinking a TRV in all bedrooms and lounge, then normal ones in hall and kitchen set pretty low, and normal ones in bathroom towel rails set a bit higher?
The 2 rads in the lounge could report to a single wireless thermostat to set the tempature that way? At least thats how Tado imply it will work with multi rads in 1 room.

Dunno about Tado but the Wiser stuff does that grouping, give it a go- it's easy enough to add WiFi heads later on.

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Smart Thermostat recommendations?

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