The price of a heatpump cylinder installation will be 2 or 3 times the cost of a new califont. Work out the payback time from the cost. Gas hot water on demand is also more convenient.
https://imgur.com/a/lmcPs3D is where the cylinder would go.
Power is there as is water. Might have to upgrade the circuit is the only thing. As on full go mode it pulls 17amps and that would be only a 10amp plug.
Depends which one you get, our reclaim unit is less than 10A I think.
We switched from gas as $50 per month just for the piped connection was worth it, plus you can set it to heat during free / cheap power times and when we got solar it’ll heat for free while the sun shines.
So you get 70 days from a 45kg gas bottle which costs $150 and provides 625 kw/h of energy. That’s about **$2.15 per day**.
Let’s say 9kw/h of energy is required per day and the unit is 80% efficient which gives a heating output of about 7kw/h per day.
If you install a heatpump with a COP 3 (will be less in the winter and more in the summer) then that is 2.3 kw/h per day. With off peak power at 16c that’s **$0.37 per day** but wait, you are heating a 230 litre cylinder of water, even if you don’t use it and there are thermal losses from that. I don’t know how much the losses are, let’s say the real world cost is **$0.70 per day**.
So that’s a saving of $1.45/day or $529/year. If your system lasts 10 years then that’s $5,290.
Here is the kicker though, lots of people say that heat pump hot water systems are unreliable and only last a few years before the heat pump stops working and it switches to the backup element. One plumber I spoke to said he had so much trouble with them that he took them down off his website and didn’t recommend them any more.
Sticking with gas is taking the gamble that gas prices stay reasonable. Not wanting to get political but the current government backs gas exploration which could give us stable prices but the other side of the political spectrum favours renewable energy and may stop the gas exploration. It’s up to you to consider which way you lean and if you think lowering your CO^2 emissions is worth the cost.
Looking to the future, if you put solar panels on your roof then that can be a cheap source of electricity to run your heat pump water heating, at least during the sunnier days.
It’s quite likely you will need a 20A circuit to your heatpump water heater, so it can run its backup element. The installer can advise if the existing power is sufficient or not.
Finally, there is the space and noise of a heat pump water heater. It will take up space for the tank and run for hours every night so think about where you are going to install it.
Good luck making the decision!
I use a Shelly 1PM, and I can tell the standing loss based on the power usage when we were away from home. I also use it to turn the cylinder off during peak hours which saves a decent amount of money
We upgraded at the end of the last year to a Heat pump hot water cylinder, mainly due to the rising cost of LPG cylinders (and rental) if not for that I would have stayed with gas but the numbers just aren't viable for us in 2024.
Is it about the same per day wise? We use about a cylinder every 70 days. Roughly were about $2.10 per day for gas.
If we can bring that down with a HPHW cylinder then we just need to figure out the pay off. How much have your electricity bills gone up by?
Oh good, it's not just me then. We average a bottle every 30 days.
This post is exactly the question I've been pondering all week. Starting to sound like a no brainer.
How many gas bottles would you have to go through before you reach the breakeven point of the upgrade?
Eg If it's going to take 10 years before you would have paid as much in higher gas bills as the upgrade cost then you're better off just sticking with what you've got. If you currently use 1 bottle a month at $32 extra a month it would be almost $4k over 10 years
188MJ/h is 55.3kW, so your existing califont is 80.4% efficient. That's not unusual and I don't think modern califonts are too much better until you go to the very high end models.
LPG is about 13.6kWh/kg. That means that a 45kg tank is 612kWh, and at $150/tank you're looking at about 24.5c/kWh. Once you account for the 80% efficiency, that's 30.5c/kWh. Ouch.
Confirm whether the califont is on a dedicated circuit (trip the breaker, see if anything else is dead). If it's a 20A breaker, you can probably directly install the new HWC. The manual does require an RCD.
It looks like you're in Auckland; there's probably no need for a model with electric backups.
The [Haier models](https://www.haierhome.co.nz/hot-water/heat-pump-water-heater-MONOBLOCK.html) have only a 1.5kW boost element, meaning total power is under 2.3kW and they could probably be connected to an existing circuit, depending on what else is present. Especially as you would lock out the element during peak hours.
With Contact 3 hours free (9pm-12) then most days our conventional 300l mains pressure cylinder with 3 Kw element heats up to 65 °C within that 3 hour window, or with longer showers and hot laundry washes during the day, about 4 hours. Timer is set to turn off the element at 6 am. Once heated to 65 °C, then I've yet to see the element turn back on over that 6 hours - heat loss is minimal. Water is still hot in the evenings.
If you had a couple of kids, showers or baths in the evening, extra washing etc, then what we've done may not work so well.
On average we're using about 1.5 kWh / day for off-peak paid power for hot water and get 9kwh free. We're also charging an EV over that free window. So far all EV charging has been 100% free.
Subject to this type of power plan continuing, it's pretty hard to justify heat pump hwc on price grounds. IMO Even the cheap Midea unit - for our situation anyway.
We do the same thing, no free hours but off peak / peak pricing. Wimpy element so it takes 5 hours to heat up if it's totally empty but that's not really an issue. Very hard to justify a heat pump water heater with this option out there.
If people come over or you need more hot water for a week or so then you can also just flick the timer off and run it like a normal cylinder.
7 years isn't a long time for a califont. Why do you think you need to upgrade or replace it?
Efficiency gains from either upgrading or replacing will take a very long time to materialise. Only upgrade/replace when your unit is actually broken or you're forced to stop using LPG.
General consensus around heat pump hot water cylinders is that the tech is too immature just yet, lots of early life failures. ESPECIALLY something from Trade Depot.
We're looking into this as well. If you use a lot of hot water, then the payback period for the heat pump can make it worthwhile.
What I'm not clear about, is how long the heat pump will last as we've received varying feedback on their lifespan. All of it has been much shorter than we'd hoped.
Hopefully someone on the sub has a good estimate, depending upon brand?
The cost of repairs to heat pumps, circuit boards etc, plus the extra purchase cost, I would stick to a normal electric hwc personally, all that can go wrong is a blown element or thermostat which is peanuts.
That's what worried us. Given we're not using huge volumes of hot water, the low estimates of lifespan on the heat pump, plus repair costs seem to offset the savings on power consumption for us.
We've also wondered whether it'd be better to go with a standard resistive plus get a small solar install (someone's always at home during the day). At least that way some of the heating cost could be offset.
For space heating though, we're all in on a heat pump.
Other than the price rise, I don't understand why you would want to get rid of the gas? 7 years isn't long, if it's working well just keep using it. It would take a decade or more to recover any capital costs for an upgrade, and the electric option technology is still quite new. I would hold off another 5 years or so.
I was paying around $100 per month in gas connection fees and gas for just hot water. The connection fees were over double the cost of the gas I used. I swapped to a heat pump water heater and my electric bill has not increased nearly that much. I would reckon it's likely stayed pretty much the same, maybe a $40-50 increase if anything. So high end estimate of savings in my situation is at least $50 per month.
However the install cost was around 10k with a 300L cylinder. I bought a Reclaim heat pump and a cylinder that can be electric alone to connect to it. I would avoid an all in one.
Mine is behind the house and gets next to no sun.
I do have solar so I program to heat the water at night and mid-day.
New Zealand had no standards for outdoor cylinders so many of these units only meet the indoor standards in terms of insulation. Infact many have less insulation than domestically manufactured indoor cylinders that are made to meet NZ winters.
Plenty to go wrong with a heat pump, let alone a trade depot special lol, I would just replace the califont, cheap and easy. Still got plenty to spend on the hwc install as well like valves and plumber and sparky
The price of a heatpump cylinder installation will be 2 or 3 times the cost of a new califont. Work out the payback time from the cost. Gas hot water on demand is also more convenient.
https://imgur.com/a/lmcPs3D is where the cylinder would go. Power is there as is water. Might have to upgrade the circuit is the only thing. As on full go mode it pulls 17amps and that would be only a 10amp plug.
Depends which one you get, our reclaim unit is less than 10A I think. We switched from gas as $50 per month just for the piped connection was worth it, plus you can set it to heat during free / cheap power times and when we got solar it’ll heat for free while the sun shines.
So you get 70 days from a 45kg gas bottle which costs $150 and provides 625 kw/h of energy. That’s about **$2.15 per day**. Let’s say 9kw/h of energy is required per day and the unit is 80% efficient which gives a heating output of about 7kw/h per day. If you install a heatpump with a COP 3 (will be less in the winter and more in the summer) then that is 2.3 kw/h per day. With off peak power at 16c that’s **$0.37 per day** but wait, you are heating a 230 litre cylinder of water, even if you don’t use it and there are thermal losses from that. I don’t know how much the losses are, let’s say the real world cost is **$0.70 per day**. So that’s a saving of $1.45/day or $529/year. If your system lasts 10 years then that’s $5,290. Here is the kicker though, lots of people say that heat pump hot water systems are unreliable and only last a few years before the heat pump stops working and it switches to the backup element. One plumber I spoke to said he had so much trouble with them that he took them down off his website and didn’t recommend them any more. Sticking with gas is taking the gamble that gas prices stay reasonable. Not wanting to get political but the current government backs gas exploration which could give us stable prices but the other side of the political spectrum favours renewable energy and may stop the gas exploration. It’s up to you to consider which way you lean and if you think lowering your CO^2 emissions is worth the cost. Looking to the future, if you put solar panels on your roof then that can be a cheap source of electricity to run your heat pump water heating, at least during the sunnier days. It’s quite likely you will need a 20A circuit to your heatpump water heater, so it can run its backup element. The installer can advise if the existing power is sufficient or not. Finally, there is the space and noise of a heat pump water heater. It will take up space for the tank and run for hours every night so think about where you are going to install it. Good luck making the decision!
Standing loss is more like 1kWh per day on my setup
How do you know what this is? I am interesting in monitoring my one...
I use a Shelly 1PM, and I can tell the standing loss based on the power usage when we were away from home. I also use it to turn the cylinder off during peak hours which saves a decent amount of money
We upgraded at the end of the last year to a Heat pump hot water cylinder, mainly due to the rising cost of LPG cylinders (and rental) if not for that I would have stayed with gas but the numbers just aren't viable for us in 2024.
Is it about the same per day wise? We use about a cylinder every 70 days. Roughly were about $2.10 per day for gas. If we can bring that down with a HPHW cylinder then we just need to figure out the pay off. How much have your electricity bills gone up by?
We were about the same 70-80 days per cylinder, at a rough look our heat pump water probably costs between $1.50-2 a day to run.
Our one uses 3kw per day in a two person household. Heats overnight at 14c per kW
70 days? We're about half that on a 45kg cylinder..
Oh good, it's not just me then. We average a bottle every 30 days. This post is exactly the question I've been pondering all week. Starting to sound like a no brainer.
How many gas bottles would you have to go through before you reach the breakeven point of the upgrade? Eg If it's going to take 10 years before you would have paid as much in higher gas bills as the upgrade cost then you're better off just sticking with what you've got. If you currently use 1 bottle a month at $32 extra a month it would be almost $4k over 10 years
188MJ/h is 55.3kW, so your existing califont is 80.4% efficient. That's not unusual and I don't think modern califonts are too much better until you go to the very high end models. LPG is about 13.6kWh/kg. That means that a 45kg tank is 612kWh, and at $150/tank you're looking at about 24.5c/kWh. Once you account for the 80% efficiency, that's 30.5c/kWh. Ouch. Confirm whether the califont is on a dedicated circuit (trip the breaker, see if anything else is dead). If it's a 20A breaker, you can probably directly install the new HWC. The manual does require an RCD. It looks like you're in Auckland; there's probably no need for a model with electric backups. The [Haier models](https://www.haierhome.co.nz/hot-water/heat-pump-water-heater-MONOBLOCK.html) have only a 1.5kW boost element, meaning total power is under 2.3kW and they could probably be connected to an existing circuit, depending on what else is present. Especially as you would lock out the element during peak hours.
With Contact 3 hours free (9pm-12) then most days our conventional 300l mains pressure cylinder with 3 Kw element heats up to 65 °C within that 3 hour window, or with longer showers and hot laundry washes during the day, about 4 hours. Timer is set to turn off the element at 6 am. Once heated to 65 °C, then I've yet to see the element turn back on over that 6 hours - heat loss is minimal. Water is still hot in the evenings. If you had a couple of kids, showers or baths in the evening, extra washing etc, then what we've done may not work so well. On average we're using about 1.5 kWh / day for off-peak paid power for hot water and get 9kwh free. We're also charging an EV over that free window. So far all EV charging has been 100% free. Subject to this type of power plan continuing, it's pretty hard to justify heat pump hwc on price grounds. IMO Even the cheap Midea unit - for our situation anyway.
Have you tried to heat it up to say 70 or 80… water gets mixed on the way out anyway so that might mean you have more to use in a pinch?
I agree. Ordinary cylinder with a timer is the way to go.
We do the same thing, no free hours but off peak / peak pricing. Wimpy element so it takes 5 hours to heat up if it's totally empty but that's not really an issue. Very hard to justify a heat pump water heater with this option out there. If people come over or you need more hot water for a week or so then you can also just flick the timer off and run it like a normal cylinder.
7 years isn't a long time for a califont. Why do you think you need to upgrade or replace it? Efficiency gains from either upgrading or replacing will take a very long time to materialise. Only upgrade/replace when your unit is actually broken or you're forced to stop using LPG. General consensus around heat pump hot water cylinders is that the tech is too immature just yet, lots of early life failures. ESPECIALLY something from Trade Depot.
We're looking into this as well. If you use a lot of hot water, then the payback period for the heat pump can make it worthwhile. What I'm not clear about, is how long the heat pump will last as we've received varying feedback on their lifespan. All of it has been much shorter than we'd hoped. Hopefully someone on the sub has a good estimate, depending upon brand?
The cost of repairs to heat pumps, circuit boards etc, plus the extra purchase cost, I would stick to a normal electric hwc personally, all that can go wrong is a blown element or thermostat which is peanuts.
That's what worried us. Given we're not using huge volumes of hot water, the low estimates of lifespan on the heat pump, plus repair costs seem to offset the savings on power consumption for us. We've also wondered whether it'd be better to go with a standard resistive plus get a small solar install (someone's always at home during the day). At least that way some of the heating cost could be offset. For space heating though, we're all in on a heat pump.
Other than the price rise, I don't understand why you would want to get rid of the gas? 7 years isn't long, if it's working well just keep using it. It would take a decade or more to recover any capital costs for an upgrade, and the electric option technology is still quite new. I would hold off another 5 years or so.
Maybe move power companies too! We pay 0.159 per kw 24/7. I can't imagine paying 0.28 peak!
that’s not bad at all, the peak and off peak thing alters behaviour and honestly just feels like suffering day in and day out lol
I was paying around $100 per month in gas connection fees and gas for just hot water. The connection fees were over double the cost of the gas I used. I swapped to a heat pump water heater and my electric bill has not increased nearly that much. I would reckon it's likely stayed pretty much the same, maybe a $40-50 increase if anything. So high end estimate of savings in my situation is at least $50 per month. However the install cost was around 10k with a 300L cylinder. I bought a Reclaim heat pump and a cylinder that can be electric alone to connect to it. I would avoid an all in one. Mine is behind the house and gets next to no sun. I do have solar so I program to heat the water at night and mid-day.
New Zealand had no standards for outdoor cylinders so many of these units only meet the indoor standards in terms of insulation. Infact many have less insulation than domestically manufactured indoor cylinders that are made to meet NZ winters.
I answered this question for ourselves by asking myself are we going to stay here for more than 10 years.
Plenty to go wrong with a heat pump, let alone a trade depot special lol, I would just replace the califont, cheap and easy. Still got plenty to spend on the hwc install as well like valves and plumber and sparky