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We could even go more basic... safe defaults when disconnected should be mandatory. For example, if I pull the thermostat off my wall, the furnace should drop

We could even go more basic... safe defaults when disconnected should be mandatory. For example, if I pull the thermostat off my wall, the furnace should drop into a fallback mode that keeps the heat above freezing (I'm in Canada where this is a concern.) I moved into a new house and did not set up the lawn irrigation system. Despite being disconnected from the cloud service, the system kept running its schedule, when I would have expected it turn off in order to conserve water.

baq 1y ago
> Despite being disconnected from the cloud service, the system kept running its schedule I'd consider this a very important feature
andylei 1y ago
your furnace doesn't know what temperature your house is if the furnace isn't connected to a thermostat
- kenhwang 1y ago
  The connection between the furnace and the thermostat probably shouldn't go through the internet. So it's perfectly reasonable for the furnace to turn off when it is disconnected, because disconnection would be a very strong signal for an error state instead of regular intermittent network/service issues.
  - kgermino 1y ago
    Are there any furnaces that do that? Certainly, the standard smart thermostat set up is that your ecobee is connected to the Internet, but controls the furnace using good old-fashioned signal wires
  - sokoloff 1y ago
    Which is only extremely tangentially related to "if I pull my thermostat off the wall" The overwhelmingly most common connection between a thermostat and furnace is a contact closure when calling for heat, with no ability to differentiate between “thermostat is present but not calling for heat” and “thermostat is not present” as both present as "these T-T contacts are not closed/shorted together".
  - InitialBP 1y ago
    I have a nest and it's wired directly to your furnace via the thermostat control wires. While it is controllable via the cloud, even without wifi it continues to function.
  - baq 1y ago
    the connection to my thermostat is via a cable, if I pull it out of the wall it won't be connected to anything at all. the whole furnace is not connected to anything but mains power.
  - duped 1y ago
    They're not, "smart" thermostats have a WiFi frontend that allows devices to connect to it from the network but the thermostat itself is hardwired to the furnace/HVAC. You could in theory put one next to the furnace in your machine closet but that would be dumb and expensive
- luxuryballs 1y ago
  yeah the default in this case has to be “off” to prevent damage from running blind, on that note other things in the house should be certified to be able to handle being frozen perhaps
  - Ccecil 1y ago
    Exactly... Fail "safe"...not Fail "keep running"
  - dghlsakjg 1y ago
    Typically when people are concerned about their house freezing in cold climates, they are primarily worried about water freezing, expanding, and cracking pipes and fittings. It is extraordinarily hard to design something that can withstand that pressure and still be fit for purpose. The item needs to be able to withstand pressures in excess of ~10k psi for -10c, with the pressure rising as temp decreases. The standard solution for people that need to winterize a building that will not be heated is to drain as much water as possible from the lines, and then fill them with a liquid with a lower freezing point.
JadeNB 1y ago
> I moved into a new house and did not set up the lawn irrigation system. Despite being disconnected from the cloud service, the system kept running its schedule, when I would have expected it turn off in order to conserve water. Not running when disconnected is definitely a safe default, but I'm not sure it's automatically desired. If I found out I couldn't use my sprinkler system unless it was connected to the internet, I'd be annoyed at the unnecessary gating of such functionality.
bongodongobob 1y ago
No, the furnace shouldn't do anything. It should fail open.
- julianlam 1y ago
  Depends on the part of the world. If you intend on turning off your furnace in Canada, you best be prepared to winterize your house too! (Lots of cottagers do this... indoor plumbing is flushed and water is turned off at the pump, etc.)
  - reaperducer 1y ago
    A burst pipe is preferential to a house that burns down.
  - bongodongobob 1y ago
    Without a thermostat you have no idea what the temperature is. We are talking about failure, not turning the furnace off.
    - immibis 1y ago
      Surely there's some reasonable duty cycle, like (I don't live in one of those places) 10 minutes on, 50 minutes off, something like that.
shreddit 1y ago
Only two examples and you are already contradicting yourself. One service should keep running and the other should turn off in the event of loosing the connection to the “outside world”. What we need is a “in the event of X - keep doing Y”.
sokoloff 1y ago
> Despite being disconnected from the cloud service, the system kept running its schedule, when I would have expected it turn off in order to conserve water. I'd have expected (and strongly prefer) that it keep running with whatever the last settings were. That's almost surely going to be healthier for the lawn, ornamentals, and vegetable garden than shutting off. I would wager that most people with automated irrigation systems prefer plant growth/protection over water conservation. I'm not sure how you'd program a furnace to run to keep a house above freezing without any temperature feedback from the house. You could potentially run it until the area immediately surrounding the furnace itself was above freezing, but that would be nowhere near enough in some cases and way, way more than needed in other cases. You might able to use outdoor weather compensation (easier/more effective/comfortable with hydronic heat distribution than with ducted air heating) if programmed correctly, but my experience is that most are either not installed or are configured to be far too hot [because call-backs are expensive and paid by the HVAC company usually].
leeter 1y ago
I've said for years that any smart thermostat should have a bimetallic backup that controls maximum ranges and acts in the dumbest way possible. Just max temp and min temp for AC and heat. Nothing that should ever be hit... but there nonetheless.
- mrWiz 1y ago
  You could just put a backup dumb thermostat in parallel with the smart one.
stevejb 1y ago
It isn't clear that 'conserve water' is a reasonable default position. Perhaps 'keep doing what it was programmed to be doing' would be a better position?
- julianlam 1y ago
  Depends... the focus here isn't on convenience or utility, but on safety. The furnace defaults to on to save the water pipes. The sprinkler defaults to off to conserve water as the system is potentially unmonitored and a burst pipe could cause issues.
  - InitialBP 1y ago
    Defaulting a furnace to on certainly shouldn't be considered safe. What if it's leaking CO into your house, what if it gets dangerously hot and causes a fire? A thermostat and controls are a necessary requirement for HVAC systems and defaulting anything to "run" if your control plane doesn't exist anymore is definitely not the safe option. The other issue is that in almost all situations (like this one) what you think is a safe and sane default won't align with what other people think. There should be defaults and they should be clearly defined, but I don't think it's always obvious to determine what they are.
    - sokoloff 1y ago
      > What if it's leaking CO into your house While I agree with your overall point, this clause is irrelevant to/not supportive of it. The presence of a thermostat wasn't going to help you here either and there are vastly more furnaces with connected thermostats than disconnected to worry about. CO detectors and alarms are needed to address this risk.
      - zdragnar 1y ago
        Your thermostat is in a far less likely place to be overloaded with CO should the alarms start going off, though. If the thermostat is gone, you have to physically go to the furnace itself or shut off power at the circuit breaker. Freezing water pipes are bad, but a furnace running non-stop is going to exceed its duty cycle and pose a greater hazard.
kgermino 1y ago
Well that brings up two immediate issues A standard furnace and thermostat won’t even know if you pull the thermostat off the wall, much less have any way to handle it beyond “full blast heat 24/7” More challenging: you expected the sprinkler setup to do the opposite. Instead of following its last-known plan (the schedule) it should stop doing anything (possibly killing the plants it’s watering) Good off-line only mode in a reasonable plan for what to do without the Internet makes a lot of sense, but at some point, there’s a control system and you need to change it (or even just have one in the thermostat example)
- julianlam 1y ago
  The way I see it is... I'd rather my lawn be yellow, plants dead, than a burst pipe underground causing significantly more expensive remediation. I agree it's not likely (especially if the system is running as-scheduled), but it was a surprise is all. What if I didn't set up the service at all, and it dropped below 0 C? I would be in for a nasty surprise in the spring.
  - kgermino 1y ago
    That's fair, though it's not a given that the sprinklers are for turf-grass instead of something more important. More interestingly (to me): did it have a local interface or was the only way to update it tied to the internet?
    - julianlam 1y ago
      There was a local interface, but I don't think it had advanced scheduling capabilities.
  - ChoGGi 1y ago
    All the irrigation lines I've seen in Canada are just a foot or so under the grass, and it's cheap plastic with cheap couplers. You have to drain them yearly.
- thewebguyd 1y ago
close04 1y ago
You can already see the “sane defaults” vary with the person. When it comes to safety it’s a bit more clear cut. The job of a heating system is to heat so don’t turn off heating when this can endanger people and houses. The job of a lawn irrigation system is to irrigate. Who wants a dead lawn just because the internet or wifi are down, or to conserve water only when the system is disconnected from the internet but not from electricity?
- julianlam 1y ago
  Fair — honestly my expectation would be that if it could not connect to the cloud service, I should be able to configure a schedule offline. That isn't the case, and so if the safe default is off, that definitely hampers utility, which isn't a very good selling point, heh.
deleted 1y ago
[deleted]

baq 1y ago

> Despite being disconnected from the cloud service, the system kept running its schedule I'd consider this a very important feature

andylei 1y ago

your furnace doesn't know what temperature your house is if the furnace isn't connected to a thermostat

kenhwang 1y ago
The connection between the furnace and the thermostat probably shouldn't go through the internet. So it's perfectly reasonable for the furnace to turn off when it is disconnected, because disconnection would be a very strong signal for an error state instead of regular intermittent network/service issues.
- kgermino 1y ago
  Are there any furnaces that do that? Certainly, the standard smart thermostat set up is that your ecobee is connected to the Internet, but controls the furnace using good old-fashioned signal wires
- sokoloff 1y ago
  Which is only extremely tangentially related to "if I pull my thermostat off the wall" The overwhelmingly most common connection between a thermostat and furnace is a contact closure when calling for heat, with no ability to differentiate between “thermostat is present but not calling for heat” and “thermostat is not present” as both present as "these T-T contacts are not closed/shorted together".
- InitialBP 1y ago
  I have a nest and it's wired directly to your furnace via the thermostat control wires. While it is controllable via the cloud, even without wifi it continues to function.
- baq 1y ago
  the connection to my thermostat is via a cable, if I pull it out of the wall it won't be connected to anything at all. the whole furnace is not connected to anything but mains power.
- duped 1y ago
  They're not, "smart" thermostats have a WiFi frontend that allows devices to connect to it from the network but the thermostat itself is hardwired to the furnace/HVAC. You could in theory put one next to the furnace in your machine closet but that would be dumb and expensive
luxuryballs 1y ago
yeah the default in this case has to be “off” to prevent damage from running blind, on that note other things in the house should be certified to be able to handle being frozen perhaps
- Ccecil 1y ago
  Exactly... Fail "safe"...not Fail "keep running"
- dghlsakjg 1y ago
  Typically when people are concerned about their house freezing in cold climates, they are primarily worried about water freezing, expanding, and cracking pipes and fittings. It is extraordinarily hard to design something that can withstand that pressure and still be fit for purpose. The item needs to be able to withstand pressures in excess of ~10k psi for -10c, with the pressure rising as temp decreases. The standard solution for people that need to winterize a building that will not be heated is to drain as much water as possible from the lines, and then fill them with a liquid with a lower freezing point.

JadeNB 1y ago

> I moved into a new house and did not set up the lawn irrigation system. Despite being disconnected from the cloud service, the system kept running its schedule, when I would have expected it turn off in order to conserve water. Not running when disconnected is definitely a safe default, but I'm not sure it's automatically desired. If I found out I couldn't use my sprinkler system unless it was connected to the internet, I'd be annoyed at the unnecessary gating of such functionality.

bongodongobob 1y ago

No, the furnace shouldn't do anything. It should fail open.

julianlam 1y ago
Depends on the part of the world. If you intend on turning off your furnace in Canada, you best be prepared to winterize your house too! (Lots of cottagers do this... indoor plumbing is flushed and water is turned off at the pump, etc.)
- reaperducer 1y ago
  A burst pipe is preferential to a house that burns down.
- bongodongobob 1y ago
  Without a thermostat you have no idea what the temperature is. We are talking about failure, not turning the furnace off.
  - immibis 1y ago
    Surely there's some reasonable duty cycle, like (I don't live in one of those places) 10 minutes on, 50 minutes off, something like that.

shreddit 1y ago

Only two examples and you are already contradicting yourself. One service should keep running and the other should turn off in the event of loosing the connection to the “outside world”. What we need is a “in the event of X - keep doing Y”.

sokoloff 1y ago

> Despite being disconnected from the cloud service, the system kept running its schedule, when I would have expected it turn off in order to conserve water. I'd have expected (and strongly prefer) that it keep running with whatever the last settings were. That's almost surely going to be healthier for the lawn, ornamentals, and vegetable garden than shutting off. I would wager that most people with automated irrigation systems prefer plant growth/protection over water conservation. I'm not sure how you'd program a furnace to run to keep a house above freezing without any temperature feedback from the house. You could potentially run it until the area immediately surrounding the furnace itself was above freezing, but that would be nowhere near enough in some cases and way, way more than needed in other cases. You might able to use outdoor weather compensation (easier/more effective/comfortable with hydronic heat distribution than with ducted air heating) if programmed correctly, but my experience is that most are either not installed or are configured to be far too hot [because call-backs are expensive and paid by the HVAC company usually].

leeter 1y ago

I've said for years that any smart thermostat should have a bimetallic backup that controls maximum ranges and acts in the dumbest way possible. Just max temp and min temp for AC and heat. Nothing that should ever be hit... but there nonetheless.

mrWiz 1y ago
You could just put a backup dumb thermostat in parallel with the smart one.

stevejb 1y ago

It isn't clear that 'conserve water' is a reasonable default position. Perhaps 'keep doing what it was programmed to be doing' would be a better position?

julianlam 1y ago
Depends... the focus here isn't on convenience or utility, but on safety. The furnace defaults to on to save the water pipes. The sprinkler defaults to off to conserve water as the system is potentially unmonitored and a burst pipe could cause issues.
- InitialBP 1y ago
  Defaulting a furnace to on certainly shouldn't be considered safe. What if it's leaking CO into your house, what if it gets dangerously hot and causes a fire? A thermostat and controls are a necessary requirement for HVAC systems and defaulting anything to "run" if your control plane doesn't exist anymore is definitely not the safe option. The other issue is that in almost all situations (like this one) what you think is a safe and sane default won't align with what other people think. There should be defaults and they should be clearly defined, but I don't think it's always obvious to determine what they are.
  - sokoloff 1y ago
    > What if it's leaking CO into your house While I agree with your overall point, this clause is irrelevant to/not supportive of it. The presence of a thermostat wasn't going to help you here either and there are vastly more furnaces with connected thermostats than disconnected to worry about. CO detectors and alarms are needed to address this risk.
    - zdragnar 1y ago
      Your thermostat is in a far less likely place to be overloaded with CO should the alarms start going off, though. If the thermostat is gone, you have to physically go to the furnace itself or shut off power at the circuit breaker. Freezing water pipes are bad, but a furnace running non-stop is going to exceed its duty cycle and pose a greater hazard.

kgermino 1y ago

Well that brings up two immediate issues A standard furnace and thermostat won’t even know if you pull the thermostat off the wall, much less have any way to handle it beyond “full blast heat 24/7” More challenging: you expected the sprinkler setup to do the opposite. Instead of following its last-known plan (the schedule) it should stop doing anything (possibly killing the plants it’s watering) Good off-line only mode in a reasonable plan for what to do without the Internet makes a lot of sense, but at some point, there’s a control system and you need to change it (or even just have one in the thermostat example)

julianlam 1y ago
The way I see it is... I'd rather my lawn be yellow, plants dead, than a burst pipe underground causing significantly more expensive remediation. I agree it's not likely (especially if the system is running as-scheduled), but it was a surprise is all. What if I didn't set up the service at all, and it dropped below 0 C? I would be in for a nasty surprise in the spring.
- kgermino 1y ago
  That's fair, though it's not a given that the sprinklers are for turf-grass instead of something more important. More interestingly (to me): did it have a local interface or was the only way to update it tied to the internet?
  - julianlam 1y ago
    There was a local interface, but I don't think it had advanced scheduling capabilities.
- ChoGGi 1y ago
  All the irrigation lines I've seen in Canada are just a foot or so under the grass, and it's cheap plastic with cheap couplers. You have to drain them yearly.
thewebguyd 1y ago

close04 1y ago

You can already see the “sane defaults” vary with the person. When it comes to safety it’s a bit more clear cut. The job of a heating system is to heat so don’t turn off heating when this can endanger people and houses. The job of a lawn irrigation system is to irrigate. Who wants a dead lawn just because the internet or wifi are down, or to conserve water only when the system is disconnected from the internet but not from electricity?

julianlam 1y ago
Fair — honestly my expectation would be that if it could not connect to the cloud service, I should be able to configure a schedule offline. That isn't the case, and so if the safe default is off, that definitely hampers utility, which isn't a very good selling point, heh.

deleted 1y ago

[deleted]