What smart themostart are using?

[squerble]

Hi many thanks. Yes I definitely have 3 zones, so it's likely going to cost more. Hoping it doesn't go above £500 for the entire setup! With your setup with the TRV‘s how much did you pay in the end please?

I’m still rocking basic wall programmable thermostats for my upstairs and downstairs zones. I looked into a Drayton Wiser system, but to get one that supports my zone valves and get the TRVs on all radiators I was looking at it costing over £700. It’ll never ever make that money back in savings so it was just an indulgence to be able to heat a single room.

That said I’m still considering swapping the two thermostats for two of the wired Tado° just so I can have some extra control as well as some sense of “reporting” on how the temperature fluctuates in the house and how long the heating is actually burning for… but that’s still going to be £300 for the privilege.

 

[squerble]

You can't change the settings from your phone remotely if that is the case, but I can still press the button on the controller thing on the wall to change the temp up/down and I believe it will still keep the schedule, you just wouldn't be able to change it.

I've been having a look at the Tadoº, and if the internet goes down you lose control from your phone (as expected), but the schedule no longer works either. So this means with no internet your heating won't be coming on as scheduled (let's say at work during the day and the internet goes down just before the scheduled on time ready for you getting home). We can also take from this that if Tado are having server/service issues, then we also lose schedule. That's not great... it's not the worse thing in the world of course, but the fact you lose even a basic schedule without internet is a bit much.

Details here: https://support.tado.com/en/article...rol-my-heating-or-air-conditioning-using-tado

 

[tsobo]

Hmm. What I don't understand is most are saying that as most of the systems cost over £700 if they install, they will not benefit from any savings. How is this possible though, looking at the increasing cost of heating. I'm the opposite, I feel that these systems help to stop wasting heating, especially those designed for controlling heating in individual rooms, or I'm missing something?

 

[jpaul]

remote TRV saving/benefit is just down to individual ability/inability to manually adjust the radiators in unused rooms, we don't have that many configurations, so not an issue.
modulation of the boiler is where the cost savings are to be had.

without a modulating/opentherm thermostat I'd lke to know if out ideal+ does modulate burner when meeting the output flow temperature target - does it turn down the flame as that target is achieved ?

 

[Richie]

I only have Nest thermostats here but it still saves energy as I have the presence sensing turned on so, even if the schedule says to turn the heating on at a certain time, the presence sensing overrides it and keeps it off if the house is empty.

 

[tsobo]

I only have Nest thermostats here but it still saves energy as I have the presence sensing turned on so, even if the schedule says to turn the heating on at a certain time, the presence sensing overrides it and keeps it off if the house is empty.

My thoughts exactly. I know you could just manually switch on and off radiators, but the convinience of using an app to switch on and off certain rooms definitely helps.

 

[squerble]

remote TRV saving/benefit is just down to individual ability/inability to manually adjust the radiators in unused rooms, we don't have that many configurations, so not an issue.
modulation of the boiler is where the cost savings are to be had.

without a modulating/opentherm thermostat I'd lke to know if out ideal+ does modulate burner when meeting the output flow temperature target - does it turn down the flame as that target is achieved ?

You'd be hard pressed to find any boiler which doesn't modulate their burners these days; your Ideal definitely will. A bigger issue is boilers being oversized - our Ideal, for example, can only modulate down to 7kW on the heating, which is insanely high. I doubt our heat loss was much more than 1kW even in the coldest of temps earlier this month.

This is where setting up OpenTherm with boilers could potentially lose money! Because the boiler can't modulate low enough to keep the flow temperature held with a steady flame, it is constantly cycling the burner, which causes a lot of efficiency loss, as well as additional wear and tear on the boiler. We'd need a boiler that could modulate down to <1kW for it to work properly in our house. This issue is exacerbated when you use OpenTherm, because it's lowering the flow temp, which requires less heat input, which means even more cycling.

 

[Bug One]

I don't have any easy way to get mains power in to the ideal location of my thermostat.

Considering the unit on the wall will have to be wireless and battery powered, which would be the best system?

 

[robj20]

You'd be hard pressed to find any boiler which doesn't modulate their burners these days; your Ideal definitely will. A bigger issue is boilers being oversized - our Ideal, for example, can only modulate down to 7kW on the heating, which is insanely high. I doubt our heat loss was much more than 1kW even in the coldest of temps earlier this month.

This is where setting up OpenTherm with boilers could potentially lose money! Because the boiler can't modulate low enough to keep the flow temperature held with a steady flame, it is constantly cycling the burner, which causes a lot of efficiency loss, as well as additional wear and tear on the boiler. We'd need a boiler that could modulate down to <1kW for it to work properly in our house. This issue is exacerbated when you use OpenTherm, because it's lowering the flow temp, which requires less heat input, which means even more cycling.

Any decent Opentherm setup will include safeguards for such an event. Mine certainly does where you can say a cycle rate and minimum on time.

 

[squerble]

Any decent Opentherm setup will include safeguards for such an event. Mine certainly does where you can say a cycle rate and minimum on time.

You've conflated two issues here. I know thermostats have anti-cycling built-in, so only allowing 3 changes from "on" to "off" per hour etc.

What I'm talking about is the flame modulation internal to the boiler, which no thermostat can control, regardless of using OpenTherm or normal on/off stats - whenever the heating is being called, the boiler attempts to maintain a set flow temperature by modulating the flame size. But unfortunately, in larger boilers especially, even at their lowest flame modulation they cannot keep at the set point once the system is up to temperature because they're simply adding too much energy. So the burner is cycled on and off, not the heating system itself. This is controlled by the physical properties of, and the electronics in, the boiler and so can't be changed.

Worse still is that most boilers can't ignite on their lowest flame modulation, so they have to start on 50+%, meaning they fire, the flow temperature rises above the set point before the boiler can modulate down, and so the burner has to be turned off again. Rinse and repeat. Now, most boilers have their own internal anti-cycling too which won't let the burner be turned on/off too many times per minute (or require at least 1 minute before the burner can ignite again etc etc), but it still can't get around the fact that even at their lowest setting, these modern boilers are adding far too much energy into the heating system. This constant cycling reduces efficiency, meaning even with condensing boilers claiming 90%+ efficiency, you won't be getting it, even if the flow temperature is in the "condensing" range.

This issue is exacerbated further by using OpenTherm, a system which modulates the flow temperature set point, not the flame size. So as the rooms get closer to their set temperature, the stat tells the boiler to lower its flow temperature so the rooms don't overshoot their set point. By asking the boiler for a lower flow temperature, it now needs to add even less energy into the system.


Boilers modulate their flame size to maintain a set flow temperature; OpenTherm modulates that set point.


EDIT: Fixed a bit of spelling

 

[robj20]

You've conflated two issues here. I know thermostats have anti-cycling built-in, so only allowing 3 changes from "on" to "off" per hour etc.

What I'm talking about is the flame modulation internal to the boiler, which no thermostat can control, regardless of using OpenTherm or normal on/off stats - whenever the heating is being called, the boiler attempts to maintain a set flow temperature by modulating the flame size. But unfortunately, in larger boilers especially, even at their lowest flame modulation they cannot keep at the set point once the system is up to temperature because they're simply adding too much energy. So the burner is cycled on and off, not the heating system itself. This is controlled by the physical properties of, and the electronics in, the boiler and so can't be changed.

Worse still is that most boilers can't ignite on their lowest flame modulation, so they have to start on 50+%, meaning they fire, the flow temperature rises above the set point before the boiler can modulate down, and so the burner has to be turned off again. Rinse and repeat. Now, most boilers have their own internal anti-cycling too which won't let the burner be turned on/off too many times per minute (or require at least 1 minute before the burner can ignite again etc etc), but it still can't get around the fact that even at their lowest setting, these modern boilers are adding far too much energy into the heating system. This constant cycling reduces efficiency, meaning even with condensing boilers claiming 90%+ efficiency, you won't be getting it, even if the flow temperature is in the "condensing" range.

This issue is exacerbated further by using OpenTherm, a system which modulates the flow temperature set point, not the flame size. So as the rooms get closer to their set temperature, the stat tells the boiler to lower its flow temperature so the rooms don't overshoot their set point. By asking the boiler for a lower flow temperature, it now needs to add even less energy into the system.


Boilers modulate their flame size to maintain a set flow temperature; OpenTherm modulates that set point.


EDIT: Fixed a bit of spelling

Your not telling me anything I don't know. You specifically said Opentherm can makes things worse. I pointed out that some systems get around that by basically having override settings if the required flow is unobtainable.
Mine will somewhat switch back to a simple on off and only come on and off once an hour rather than cycling constantly to maintain a silly low flow temperature.
So it certainly won't risk extra wear and tear.

 

[squerble]

Your not telling me anything I don't know. You specifically said Opentherm can makes things worse. I pointed out that some systems get around that by basically having override settings if the required flow is unobtainable.
Mine will somewhat switch back to a simple on off and only come on and off once an hour rather than cycling constantly to maintain a silly low flow temperature.
So it certainly won't risk extra wear and tear.

But in the time that the heating is called in that hour, the boiler's burner will still be cycling, even more so when OpenTherm is telling the flow temperature to stay low.

 

[robj20]

But in the time that the heating is called in that hour, the boiler's burner will still be cycling, even more so when OpenTherm is telling the flow temperature to stay low.

Not on mine it doesn't. Did you even read my post.

If it gets to the point it would go over the cycle rate I have set it gives up with that temperature and requests higher and cycles less. This having a kind of hybrid system.

For instance if it wants 25c and the boiler can't do it without cycling too many times it would do 30c for 40mins in the hour and cycle once.

 

[BennyC]

What is the rubbish about smart heating being useless if your internet goes down. It reverts to being a dumb system so you manually set the temp via the thermostat and/or TRV

I've got Hive, not idea how much money it saves me but being able to turn off a rad in unoccupied rooms works well so it must be saving some money

Surely with no internet it should still function normally on the local network whilst at home?

I toyed with the idea of upgrading my boiler controls and thermostat to a smart solution but given I never touch my thermostat and have already reduced how regularly and how long my water is heated any payback would take quite some time.

 

[squerble]

Not on mine it doesn't. Did you even read my post.

If it gets to the point it would go over the cycle rate I have set it gives up with that temperature and requests higher and cycles less. This having a kind of hybrid system.

For instance if it wants 25c and the boiler can't do it without cycling too many times it would do 30c for 40mins in the hour and cycle once.

OK, what's your boiler and stat setup?

Surely with no internet it should still function normally on the local network whilst at home?

I toyed with the idea of upgrading my boiler controls and thermostat to a smart solution but given I never touch my thermostat and have already reduced how regularly and how long my water is heated any payback would take quite some time.

On the Tado, it specifically says the schedule is lost without internet. You can manually set a temp on the local stat, but you lose control via phone (seems the bridge has to function via Tado's servers, as you can't access it locally, even though it'll have an IP address as it's plugged into a switch/router).

 

[Relentless81]

Surely with no internet it should still function normally on the local network whilst at home?

I toyed with the idea of upgrading my boiler controls and thermostat to a smart solution but given I never touch my thermostat and have already reduced how regularly and how long my water is heated any payback would take quite some time.

Do you mean the app? Depends on the system, some need an internet connection to communicate with the hub, not sure which

 

[robj20]

OK, what's your boiler and stat setup?

Boiler has no settings other than pump head to 70% everything is done via Opentherm.
Stat from memory is set to cycle count 2 and minimum on time of 15 minutes.
It appears to keep it happy and is over and above what Ideal Tech said was a safe point which I thing was 8 times an hour. 2 minutes on time.

 

[GSXRMovistar]

Had Nest for almost 7 years, does what it says it does. Would like the option of connected TRVs (which may even be an option now) but other than that all good.

 

[squerble]

Boiler has no settings other than pump head to 70% everything is done via Opentherm.
Stat from memory is set to cycle count 2 and minimum on time of 15 minutes.
It appears to keep it happy and is over and above what Ideal Tech said was a safe point which I thing was 8 times an hour. 2 minutes on time.

Thanks, but what actual model boiler and thermostat is it?

 

[robj20]

Thanks, but what actual model boiler and thermostat is it?

You did ask for setup not make and model.
Ideal Vogue Gen2 and Honeywell Evohome.