I can’t find any technical data on one of our two existing air conditioners. It’s 1960s through-window technology, and it seems it might be somewhere around 130% efficient. A run-of-the-mill air conditioner today is about 400% efficient. What I do know is, when that air conditioner runs our power consumption spikes 2kW; for the cooling we’re getting, this suggests we should be using 700W. It’s costing 40 cents/hour more to run than a modern unit, and it isn’t providing us with heating. It also sounds like a jet aircraft. We don’t use it much.
If it’s replaced with a $2000 unit, the payback is 5000 operating hours. It actually operates for something like 150 or 200 hours a year, so there’s a more than 25 year payback – which isn’t outlandish, given the existing unit is 50 years old now, but I will be surprised if a unit manufactured today survives that long.
Modern units come with DRED support.
Picking an air conditioner is… complex. We’ve taken our home off gas, so we need some kind of electric heating, which I expect to run daily for a number of hours for four months of the year, and the cooling side is something that will get much less use. So, where I live, I need to optimize my “heat pump” for heating performance – COP in the lingo.
As of March 2020, there are more than 3700 air conditioners with performance metrics listed by the Australian government. Thankfully this data is available is CSV format, so can be folded, sorted and mangled. 2000 can be eliminated because they’re not single-split units, so their efficiency will suck balls. Another 450 can be eliminated because they’re not the classic wall hung variety, so will be stupid expensive. Anything smaller than 3KW and larger than 5KW is badly sized for the areas I’m looking at, so now I’m at a “manageable” 300 units. Purging others for efficiency reasons, and I’m down to less than 80. I sort for COP, and start down the list. The first is $2550, then $1420, then can’t be purchased anywhere, then $880 (a ten-year TCO of $3000, plus installation). A feature check confirms it can be set to a weekday operating cycle and a weekend cycle; we’re off to the races. I locate a supplier who will deliver two for $1,716.00 after trying the local retailer who refuses to answer the phone.
Now for the easy task: I’ve simply got to find a tradie to install my units.
All my electricity is green: my retailer buys RECS sufficient to back my electricity purchases. As such, I don’t care how much electricity I use, except such that it costs me money.
Breakeven analysis is fun.
My house has a twelve year old 160 litre resistive electric hot water service (HWS). General opinion seems to be that a HWS will last perhaps as long as 12 years before failing (my last house had one that was 30 years old and still going strong). It’s currently inside the house (taking up valuable floorspace), and may not survive being moved outside in the coming renovation. I want an instantaneous gas HWS (unlimited hot water at exactly the temperature I dictate), but refuse to use gas.
Instantaneous electric HWS exist and are only about $1000, but require three-phase power (an upgrade costing a surprisingly small $1000, plus electrical work on my side of the divide). How much power will it consume? Turns out, the same as resistive heating the water, but it’s all peak electricity. That pushes its daily cost quite high. There are other HWS options; reusing the existing tank (free-ish), replacing it with a larger tank (still resistive, $1000), sucking up all the spare electricity from the PV solar system (perhaps $1000), or a heat pump ($3400), and combinations of the above.
I was able to figure out how much electricity we’re using to power our HWS by virtue of it being on a separate meter to the rest of the house – 4.6kWh/day, costing about $0.85/day because it runs off peak. Hot water consumption is expected to increase after the renovations. It turns out that how much hot water is consumed, and when, is very important for accurately pricing electricity consumption. I’ve a fairly complex spreadsheet modeling current and projected consumption patterns, and the resultant energy requirement timing and costs. We have a PV solar system, which is how I thought I could push our cost of hot water down – heat it from the panels during the day, when electricity is cheap for me ($0.119/kWh). If your tank is too small (which ours will be/nearly is already) then you’ve got to heat using electricity other than cheap solar electricity.
I calculated the Total Cost of Ownership at the 5 year mark, and the average daily cost of hot water for the various options (note, this is for my projected hot water consumption profile – yours will differ, altering the values):
Keep existing HWS, peak electricity
Keep existing HWS, off peak only, coupled to instantaneous electric HWS
Buy 315L resistive HWS, off peak only
Keep existing resistive HWS, run off PV solar and off-peak
Buy 315L resistive HWS, run off PV solar
Buy 315L heat-pump HWS, run off PV solar
The heat pump can run off solar using its built-in clock, saving $1000 in diverter costs. You can see that its TCO is a little more than a salvage job on the existing HWS run from solar power, but the daily cost means the heat pump is going to pull away at a mad rate. Hot water that cheap is making me think of grand ways to heat my house.
All my electricity is green: my retailer buys RECS sufficient to back my electricity purchases. When I calculated my household’s Green House Gas emissions equivalence, we pulled in emissions below 15% of that of the average Australian household. In fact, our emissions were down to two sources: our car (7000 km/year @ 9l/100km – emitting a quarter of that of the average Australian household) and our natural gas consumption (20300MJ/year – home heating emissions 57% of that of the average Australian household). Apparently emissions can vary from 3 to 30 tonnes/year – I’ve calculated my household at around 2.5 tonnes per year at the moment. I think we can do better. How about 1.5 tonnes per year?
I’ve had a poke around the non-hydrocarbon motorised transport market. There isn’t much there for me, cars are north of $50,000, lifespans are limited. If I could buy an electric car for $20,000 that was going to last 20 years, I’d be up for it. Because I can’t, hydrocarbons will continue to be used for this form of transport. Will revisit when car fails, I’m guessing in less than a decade. Besides, I’m pretty convinced “car ownership” will end up being something people did in the 20th century, not the 21st.
We don’t cook with gas; we have an induction cooktop. I hate electric cooking – resistive electric cooking. It’s inefficient, slow, too cold, too hot, ugly and messy and too expensive. I’ve always cooked on gas. Induction cooking has turned me around; it’s everything gas cooking is, without the explosions, burnt-on gunk, poisoning and GHG emissions. However, it is fussy (it only works with ferrous cookware) but that’s inconvenient, not a showstopper (example: coffee pecolators are almost all aluminium, and those that aren’t have a very small base. The pecolator has to go in a small pot to be used).
Our gas consumption is purely for space heating via a ducted heating system. It costs less than $770/year to heat our house, so an electric replacement will need to be competitive with that. Having run the numbers, I’ve calculated our gas consumption produced 4000kWh of heat in the house each year. Doing that with air conditioners would (assuming 400% efficiency, which is pretty middle-of-the-road) require 1000kWh of electricity. I seem to pay about 30 cents/kWh (if you can figure out what your electricity actually costs you, I’d love to hear what you did to get that number), so that’s $300/year to run air conditioners instead of ducted heating. Payback is less than 10 years if $4000 is spent on adding aircon units.
From an environmental and financial perspective it’s time to ditch gas, so I’m off. Each gas bill raises the daily connection fee. It’s about $1/day now, so if you don’t use much gas there’s an increasing incentive to use no gas at all. Nearly half my bill is for the privilege of having a gas supply.
But wait! I love wok cooking, and there’s almost no way to wok-fry stuff without gas. What to do? For a couple of years we’ve used a butane camp stove as a stop-gap until we got around to plumbing in our dedicated wok burner, but if we’re cutting off gas we’ll continue living like animals for the rest of our squalid lives! No fear, says my plumber: convert to LPG – like used for BBQ cooking. And so, we now happily wok-fry on gas, which I figure will cost us $30 – $60 a year to refill the bottle. $38 for the LPG conversion kit for the burner, which would have been avoided if I’d thought this all through a couple of years ago when buying the wok burner.
I’m lucky enough to have central heating in my house, and as the weather is cold in SE Australia at this time of year, we’ve been using it a bit.
Every few years a strong storm will blow out the pilot light. To fix it I climb up into the roof (fortunately I have an attic ladder fitted) and re-light it. Generally the effort involved to re-learn how to light it is more than the effort to actually do it.
So I’m doing like any good geek would: documenting it.
The unit is a Brivis Wombat 92 (I assume that means it’s a 1992 model). The instructions are written in tiny writing on a label attached to the inside of cover — so tiny it’s quite difficult to read while in the cramped roof space.
The steps are actually pretty quick and easy, as follows:
1. Make sure the heater control (eg in the house) is set to Off, and grab yourself a torch if you have to climb into the roof.
2. Take off the cover. On mine you pull it upwards, but I think my unit is actually mounted upside-down, judging from the logo on the side.
3. Find the dial. Turn it clockwise to the Off position.
4. Find the power point for the unit. The power cord on my unit leads to a power point about a metre away, mounted on a joist. Switch it off.
5. Wait a few seconds and switch it on again. You will hear a regular clicking sound – this is the heater trying to re-light. You’ve got about 20 seconds for the next step.
6. Turn the dial back to the Light position and press down on it. A couple of clicks later you should hear the pilot light.
7. If all looks well, now turn the dial to On. That’s it! Put the cover back on. Enjoy the heat.
So basically, you’re turning it off then on again.
If it doesn’t work? I guess try it again. I know in 2013 mine wouldn’t re-light, and needed a service, but that’s perhaps not surprising for a 20 year old unit.
(Edit: Added to turn the dial to On when the pilot has been lit. Thanks for the feedback!)
As the current home reno project is a kitchen rebuild (walls added and removed, nothing left behind – it’s dramatically more than a remodel) the first step followed was to acquire all the appliances (constructing the kitchen and then finding the oven that you’ve got a very specific sized hole made for is “no longer available” would be… disappointing).
One of the acquisitions was two Viali VCCG90SS rangehood extractor units, one for each cooktop. Noise during operation, rated capacity and acquisition cost all seem acceptable. The instruction manual seems, at first glance, fabulous: large, clear font, line drawings giving unit dimensions, step-by-step installation images and all in a matte A4-sized, easy-to-read format.
When you actually read the instruction manual with the intent of following the instructions for installation, that’s when you run into some difficulties. Let’s be clear: I’ve installed a couple of ducted extractor fans in the past, so rangehoods are not some unknown quantity for me. This is not my first rodeo. I consider myself handy, I’ve installed kitchens from the ground up. I’ve spent quite some time puzzling over this booklet, I’ve searched the Interwebs, I’ve really battled with this.
I will now try to explain how the heck you’re meant to install this Viali rangehood, because the shipped instructions sure don’t. Perhaps I’ll do it via annotation. Continue reading →
It is a good idea to keep your computer systems up-to-date, by installing the latest software fixes. But there is one fix that Telstra needs to request and install, to fix a bug lurking on Telstra’s landline telephone system which scammers are making use of.
This is Part 4 of 4 of Scammers making use of Telstra landline bug.
to learn more about testing your landline and protecting yourself, read Part 2
To find out how I became an unwitting victim 21 years ago, read Part 3.
Here, we explore some myths and facts about this bug, and I have some requests for information (please comment if you can answer any of the questions).
Facts and myths
Scammers can intercept calls you make (shortly after they call you)
They’re intercepting all calls that everyone is making to 000, or the bank The truth: there’s been a few crimes like this in the past (against radio stations), but not this time. Only one person’s calls get intercepted.
An evil caller can control your landline, preventing you from making calls, for up to five minutes.
Scammers can make calls to sex lines in Nigeria from your line The truth: They cannot; if you see such calls on your bill, it was probably a family member or employee.
Scammers can imitate the bank’s phone menu (or they could make a temporary, actual connection which they cut off at the right time)
This bug enables them to fake my Caller ID The truth: A separate hack applies to Caller ID, which the scammer might also use as part of their fraud.
An evil caller can prevent other callers from getting through to you (they get busy tone).
They can listen in on everyone who calls you The truth: They have to physically wire a listening device across your line to do that. The method described here only allows a scammer to intercept calls you make, shortly after their call.
There is no indication if a call is still connected on the line after you hang up.
A scammer can be secretly connected to your line at any time The truth: It doesn’t “just happen”. They have to call you first, and the effect only lasts for five minutes (maximum, in Australia).
Mechanical exchanges also had this characteristic
Land of the Long Held Call
Land of the Long White Cloud
Every country operates like this The truth: Only a few countries have this bug. New Zealand, Canada, the U.S., and many other countries do not have this bug. And mobile phone systems do not have this bug, either.
Various scams and tricks arising from this bug have been in use for some time. In the past, there was no five-minute timer, so it was possible to lock out someone’s line for weeks. Journalists and reporters, having interviewed someone for a story, would leave the call open preventing competeting journalists from calling their victim and getting the same story.
Surely the Police would speak to Telstra about this? The (horrible) truth: I’m not convinced it’s even occurred to them that it’s a bug, nor am I convinced that they’ve actually spoken to Telstra about it. But I am sending information to the Police about this, firstly to ascertain what has transpired, and secondly, (from a crime prevention perspective) to persuade them to be more on the front foot with Telstra on this issue. The only sign of action by the authorities I can find is the British Financial Ombudsman Service has called for action by (British) telecoms companies to remedy the flaw in hanging up phone lines.
Where is the bug?
It is in the telephone exchanges – specifically, the software running inside the exchange. This has to be fixed, either by the manufacturer of the telephone exchanges (Ericsson), or by someone changing a configuration setting. Telstra has to request this in either case, and it is likely to take 3-6 months to fix.
The official term for this is CSH (Called Subscriber Held) or A-party Release. I call it a nasty bug, but unfortunately, it is hard to convince Telstra that this needs fixing.
I have some questions
While researching anything like this, it is natural for questions to arise. Does anyone have information on anything below, or anything else? Please leave a comment.
Note that comments usually require approval before appearing, which I generally check three times a day … agree or disagree, I approve “anything” on-topic.
Australia: Does anybody using Optus Cable (or other HFC services) experience the problem? Please do the test to find out.
New Zealand: Did CSH apply on Crossbar or Step-by-Step exchanges (say, before 1980)?
New Zealand – TelstraClear subscribers: Can someone do a test, to see if CSH applies to Telstra’s exchanges in NZ? You are probably a TelstraClear subscriber if your telephone number begins with 9xx xxxx, and if your TelstraClear bill shows a line item for Telephone Line Rental or Monthly Charges.
Britain: There was a proposal to reduce the CSH hold period to 10 seconds. Was this implemented?
U.S.: I don’t want to believe the movies too much 🙂 but they frequently show the B-party hanging up and the A-party receiving dial tone. Is that true?
All countries: Please do the test. It’s for your benefit to be aware of the situation, as well as our curiosity 🙂
If you have information, please fill out a comment (note: DELAY before it appears, for most people).
It is only just this week that it occurred to me that I was most likely an unwitting victim of this bug, 21 years ago (early 1995). The planned Facts and myths about this landline bug will now be Part 4.
This is Part 3 of Scammers making use of Telstra landline bug. Read about the scam in Part 1, and learn how to test your landline for the bug in Part 2.
An unwitting victim
I was not able to call for an ambulance to a neighbour’s kitchen knife accident.
Of the six people involved in the incident, only my wife and I understand English clearly, which added to the problems/confusion.
My mother-in-law was visiting neighbours when she called out to us there had been an accident in the kitchen (and then continued in Khmer, to my wife). I rushed into the house and saw the mother and son huddled together. The mother was clearly distressed, and there was quite a bit of blood, but there was no ongoing blood loss and they weren’t losing consciousness, so I picked up the phone to call 000. But there was an Asian voice on the line.
I hung up for a few seconds, but the voice was still there, saying “Hello, hello”. Despite saying “please hang up”, and “Emergency here, please hang up”, it was a case of message received but not understood. I asked the victims where the other telephone was (thinking the voice was on another telphone extension somewhere else in the house, unaware of the drama). And I raced around the house and into the bedroom, but found no-one and no other telephone. We had just moved in and didn’t have our own telephone, so after trying the telephone once more, I ran to the payphone down the street and called the Ambulance.
The Ambulance eventually came and took them to hospital.
In the days and weeks afterward
Me, my wife, and my mother-in-law had come from New Zealand a few months before, where one can disconnect a remote caller by simply hanging up, provided that no-one else on your line has another phone off-hook.
Diagram of telephone call
In New Zealand, phone B-x can get dial-tone provided phone B-y also hangs up.
In Australia, phone A must also hang up.
Referring to the diagram above, I raced around the house looking for phone B-y. But my mother-in-law knew the neighbours quite well and clarified there’s only one phone in the house, and that it was working (the day after), leading me to assume that it was on a party line. They were unusual in urban areas, but one of my own friends had a 2-party line in Johnsonville (NZ) in 1989 – so it definitely wasn’t impossible.
I will never be absolutely certain of the truth, but it wasn’t until a few weeks after the scam story broke, and a few days after I wrote Part 2 that I realised that this bug is a much more plausible explanation for the difficulties. It means that in Australia, both the A-party and other telephones on the B-party’s line must hang up before the B-party can get dial-tone.
TL;DR(1) – Telstra has a bug in their landline system. It’s time to get rid of it for good.
TL;DR(2) – The bug is when someone calls your landline they can prevent you from hanging up. Find out how to test, and how to protect yourself from scams.
This is Part 2 of Scammers making use of Telstra landline bug. Read about the scam in Part 1.
Yes, it is a bug
Bug, n: An error in software that causes results to be different from expected.
Section 7.2.1? Just gimme a phone that works
Let’s get one thing straight: I’m calling it a bug … #CallASpadeASpade. I certainly understand the people who point out the phone network complies with Section 7.2.1 of BT SIN 721 [pdf] (or Australia’s equivalent), but that is extraordinarily unhelpful. Most people expect calls to disconnect when they hang up. Therefore (to most people) it is a bug.
Now that’s out of the way, on to checking your landline for the bug, and protecting yourself from scams.
Testing your landline (easy)
Instructions for testing:
The most reliable test is from another landline, within the same local calling area. So you should ask a friend or neighbour. The caller is the A-party, calling your landline (the B-party).
The A-party calls the B-party who answers. RESULT: A & B parties talking.
B-party hangs up. RESULT: A-party hears silence.
[OPTIONAL] Using a mobile phone or similar, quickly call the B-party. RESULT: False busy tone.
B-party picks up (within 30 seconds). RESULT: They connect back to the A-party. A & B parties talking.
B-party hangs up. The A-party should time how long it takes before they hear disconnect (beeping) tone. LIKELY RESULT: 30 or 90 seconds, but could be five minutes.
Repeat the test, but A & B parties should swap roles. Here, you’re doing your friend a favour by testing their landline for the same bug.
The official term is CSH (Called Subscriber Held) or A-Party Hold[correction]. I call it a very nasty bug because the victim (having received an unusual call) believes they’re doing the right thing by initiating their own call to verify the circumstances, but in reality they are still connected to the A-party scammer. This bug can be used in many different ways by different scammers, particularly to glean private information from the victim, but it is also possible to simply cause confusion, or lure someone to their death.
Continue reading to learn if a scammer is still on your line after a call.
How to protect yourself
Every man and his dog is making calls (video, 0m59s)
By now, every man and his dog will have called each other and concluded their landline is vulnerable. Based on discussions with Internode (my telephone provider), Telstra has informed them that there is “nothing that can be done”. Even if they change their mind, it might take three to six months.
So, in the meantime, if you get any strange call (or they hang up just as you answer) stop and think. If you call someone else quickly, you might fall victim. You have to check your landline is genuinely free.
Probably the best way is to use your mobile telephone to call your landline; you should hear ringing through your mobile, and hear the landline ringing. You don’t have to answer your landline, so hang up (end call) on the mobile, to avoid being charged. If you can’t do that, there have been some other suggestions from various people.
If you have a toll bar on your landline, call a barred number. The wording of the message should be exactly the same. Perhaps you should organise 1900 barring now, if you don’t have it already.
Call a trusted friend or loved one. BEWARE: The scammer may still be on the line, eavesdropping.
Sidestep the issue by using a different telephone (or mobile telephone) to make your outgoing call (to the bank/police).
Wait five minutes for the line to clear The problem with this is clearing times vary significantly, and the scammer could simply defeat you by calling you again at the four-minute mark.
Complexity, complexity, complexity
Australians have a habit of making simple things complex (yes, train tickets in Melbourne are too complex for tourists and locals), but I am still stunned that the act of hanging up the telephone is this complex.
I am entitled to think that it will work as expected (as it does in New Zealand).
And I’m entitled to think that a scammer will not be able to interfere with the use of my telephone, or any other technology. CSH (as it is termed) should have died with the last mechanical exchange, and it is time to get rid of it for good, in order to protect people from fraud, as well as make the phone network simple to use.
 It could also be an error in the settings (configuration). Strictly these errors are not bugs, but someone outside the system has no way of telling, so let’s not blame them for calling it a bug?
 By S. E. Stokowski (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons
 A mobile can be used to call your landline, but I’ve only reproduced a 12-second lockout. Bear in mind you need (another) mobile phone for step 4, and you can’t swap roles for step 7.
 If you (the B-party) have the Call Waiting feature on your line, results may be different. I’d be interested to hear (submit a comment).
 Video: Telecom NZ Call Diversion television advertisement; source: YouTube.
 Look in the mirror. Just above your neck, there is a face and a head, and inside the head there is a significant mass of gray matter, neurons, and synapses. It’s called a brain, and one is strongly advised to use it. Putting your brain into gear (a.k.a. “thinking”) is the best defence against fraud. But if you’re not confident, you can also use someone else’s brain: it’s called “asking their opinion/advice”. Try it with a trusted friend or family member. Having said that, very few brains are equipped with the knowledge of this landline bug, and that is the whole point of this article.
TL;DR – When someone calls your landline, they can prevent you from hanging up, and intercept calls you make afterwards.
There is a bug lurking on Telstra’s landline telephone system which scammers are making use of. The scam is described in The Age; it usually runs like this, where a scammer (the A-party) calls a victim (the B-party):
IMPORTANT NOTE: If you are receiving malicious calls, speak with your telephone provider (most have procedures to trace calls). If these calls are life threatening, call the Police on 000, within Australia.
This is the Rolex Store manager here. Someone has attempted to use your credit card here. Please call your bank straight away and cancel your card.
Thanks. (hangs up) [NOT TRUE: Call is still connected because A-party has not hung up]
(picks up receiver, hears dial tone) [NOT TRUE: Scammer is playing fake dial tone] (Dials the number, hears the usual bank menus, and gets through to someone [Actually: the scammer’s mate].
The scammer’s mate tells a false story of an attempt to withdraw the entire victim’s savings account and pretends to place "Red Alerts" on the account.
Some days and several calls later, the victim is told the only way to protect the money is to transfer it to a "Safety Deposit" account with Barclays in the UK until Police investigations are concluded. Several victims have complied, losing $5m in the process.
While the Fairfax media (The Age) goes into the fraud in some detail, they only make cursory mention of a "long-held" cold-call scam, and they don’t even identify it as a bug.
A Software bug
The bug is that when the B-party hangs up, the call does not disconnect. It only disconnects if the A-party hangs up, or if a timeout expires.
It is a very nasty bug, because most people believe that if they initiate their own call to the bank (or Police), the call is safe. The bug does not occur in New Zealand; the call disconnects as soon as either party hangs up. This has always been the case (30+ years) .
Like any security bug in Linux/Firefox/Windows/Oracle/etc, the question naturally arises: when can we expect a fix, and what are the precautions/workarounds?
 Timeouts reportedly vary from 12 seconds to five minutes depending on the type of call: 12 seconds from a Telstra mobile, 30 seconds from a VoIP line, 90 seconds from a payphone, and "it seemed like five minutes" was also reported.
 I lived in New Zealand until the mid ’90s and never encountered the bug – and I do clearly remember several cases of being disconnected because the B-party hung up; also me accidentally hanging up on a caller and getting fresh dial tone one second later. Telecom NZ ran NEAX-61 exchanges (various types) at the time. A test done April 2016 in Auckland confirms nothing has changed.
 A hookflash allowance (two seconds) may apply – such as for subscribers with conferencing or call waiting features.
They suggested doing a factory reset on the Chromecast and removing and re-installing the Stan app.
It sounded unlikely (it’s the real-life version of the IT Crowd’s “Have you tried turning it off then on again”), but to my surprise, it actually worked.
HDMI was still a problem though. They said it wasn’t supported.
So why doesn’t Stan support HDMI? An interesting answer came back:
“We are unlikely to support this method of streaming in the future due to DRM (Digital Rights Management) contractual agreements we have with the studios we licence our content off of. If anything changes, we will be sure to let you know.”
This is puzzling, given their main competitors Netflix and Presto seem to support it.
It’s worth noting that Stan (and I believe the others) don’t support my 2011-model Samsung smart TV either. Thank goodness for the Chromecast. It’s not as easy as being able to play directly just on the TV (with no other devices required), but at least it works — and navigating menus is far easier on a tablet than a TV remote control.
As one observer (I forget who) noted — there’s little point paying extra for a smart TV (over a dumb one) when an A$49 device like a Chromecast is less likely to become obsolete — or if it does, it can be cheaply and easily replaced.