Gas Instant Hot Water

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Ultimate Geek
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#3415427 16-Sep-2025 16:47

fearandloathing:

in the media recently

https://www.rnz.co.nz/news/business/572067/customer-told-it-would-cost-7500-to-disconnect-gas

Bastards get you over a barrel. Unfortunately with a sunset industry the remaining costs get spread over a smaller number of connections so there is no hope of this going backwards short of the ComCom getting involved - not holding my breath.

Otautahi Christchurch

Handle9

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#3415430 16-Sep-2025 17:02

Jase2985:

cddt:

Interested to hear any details about this.

https://www.geekzone.co.nz/forums.asp?forumid=141&topicid=296123&page_no=7#3414065

They brought a new heat pump and decommissioned the Gas and Gas hot water.

Gas decommisioning wasn't included in the costs of this.

Jase2985

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#3415432 16-Sep-2025 17:06

Handle9:

Jase2985:

cddt:

Interested to hear any details about this.

https://www.geekzone.co.nz/forums.asp?forumid=141&topicid=296123&page_no=7#3414065

They brought a new heat pump and decommissioned the Gas and Gas hot water.

Gas decommisioning wasn't included in the costs of this.

never said it was, it was just a recent example.

xlinknz

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#3415477 16-Sep-2025 20:59

Hi all

Thank you for the replies.

Usage by volume give or take has doubled in the same 3 winter months since last year so the increase is unrelated to seasonal temperatures (We're Wellington)

I read that units can become inefficient especially 20 year old ones due to heat exchanger blockage, burner issues, thermostat/sensor issues and poor combustion. Our unit has never been serviced but servicing cost I assume is a lot less than a new unit

Has anyone found servicing an existing gas instant hot water unit made a difference to your bill? (I'm wary of replacement if a problem is not properly diagnosed!)

What costs have people experienced with replacing a gas instant hot water unit whether with has or electric?

Handle9

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#3415480 16-Sep-2025 21:06

We replaced a gas instant hot water unit around 10 years ago. The actual like for like replacement wasn't particularly expensive, maybe a few hundred dollars on top of the unit.

We did a fair bit of other gas work at the same time (new gas main, deleted a couple of gas heaters) so it's hard to fully separate it out.

mattwnz

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#3415481 16-Sep-2025 21:07

scuwp:

Sorry, but you will have to prise our gas instant hot water system out of my cold dead hands (as the saying goes). Nothing quite like it.

Yes it's got more expensive (what hasn't) and yes future supply is questionable depending who you listen too, but its a long way off being end of life IMHO.

Priced up a replacement heat pump unit at ~$9K, that would take 10+ years before we would break even! And by then it's probably not far off needing an upgrade.

Yes they use a bit more in winter, that's normal. More grunt needed to heat colder water, colder ambient operating temp, and probably longer and hotter showers. It all adds up.

I 've heard there's huge costs involved now to have gas decommissioned from a house? Like several thousand $$.

Biogas is an option for NZ. We don’t have the electricity generation for all gas users to convert to electricity and will only push up electricity prices

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Aucklandjafa

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Ultimate Geek
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#3415486 16-Sep-2025 21:40

True. But govt policy could encourage the uptake of solar/battery installs.

Stu1

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#3415488 16-Sep-2025 21:56

xlinknz:

Hi all

Thank you for the replies.

Usage by volume give or take has doubled in the same 3 winter months since last year so the increase is unrelated to seasonal temperatures (We're Wellington)

I read that units can become inefficient especially 20 year old ones due to heat exchanger blockage, burner issues, thermostat/sensor issues and poor combustion. Our unit has never been serviced but servicing cost I assume is a lot less than a new unit

Has anyone found servicing an existing gas instant hot water unit made a difference to your bill? (I'm wary of replacement if a problem is not properly diagnosed!)

What costs have people experienced with replacing a gas instant hot water unit whether with has or electric?

interested in what costs you get back, I was chatting with plumbing world in the weekend in Wellington cost would be around 10 to 15k for an equivalent to an infinity . Where a new infinity around 3.5k massive difference

Jase2985

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#3415632 17-Sep-2025 14:42

Stu1:

xlinknz:

Hi all

Thank you for the replies.

Usage by volume give or take has doubled in the same 3 winter months since last year so the increase is unrelated to seasonal temperatures (We're Wellington)

I read that units can become inefficient especially 20 year old ones due to heat exchanger blockage, burner issues, thermostat/sensor issues and poor combustion. Our unit has never been serviced but servicing cost I assume is a lot less than a new unit

Has anyone found servicing an existing gas instant hot water unit made a difference to your bill? (I'm wary of replacement if a problem is not properly diagnosed!)

What costs have people experienced with replacing a gas instant hot water unit whether with has or electric?

interested in what costs you get back, I was chatting with plumbing world in the weekend in Wellington cost would be around 10 to 15k for an equivalent to an infinity . Where a new infinity around 3.5k massive difference

The person in the other thread did it for less than $9k installed and the gas connection removed

Each to their own.

mattwnz

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#3415634 17-Sep-2025 14:47

Aucklandjafa:

True. But govt policy could encourage the uptake of solar/battery installs.

The problem with that is not everyone can do that on their property, and it potentially increases the costs for those that continue to use the grid power, as less people use it. Also many people rent and many of those are lower income. The people that often install solar and benefit are those that are often higher income and can afford to pay more for power. There are leased systems but they can be problematic especially if selling the house later on.

wellygary

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#3415638 17-Sep-2025 15:47

mattwnz:

There are leased systems but they can be problematic especially if selling the house later on.

Or if the operator goes bust-

https://newsroom.co.nz/2025/06/04/solarzero-customers-trapped-with-high-fees-everyone-wants-out/

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Aucklandjafa

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Ultimate Geek
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#3415645 17-Sep-2025 16:41

mattwnz:

Aucklandjafa:

True. But govt policy could encourage the uptake of solar/battery installs.

The problem with that is not everyone can do that on their property, and it potentially increases the costs for those that continue to use the grid power, as less people use it. Also many people rent and many of those are lower income. The people that often install solar and benefit are those that are often higher income and can afford to pay more for power. There are leased systems but they can be problematic especially if selling the house later on.

hmmm, not really, no. When you install solar and batteries, not only are you still connected to the grid - but you feed energy back into the grid for others to use - it just means, because you’re self-sufficient, there is less strain on the grid.

And of course you’re not going to get solar installed of your house receives next to no sunlight.

Regarding rentals, I’ve seen many that have solar, but regardless, from a landlord’s point of view: whilst they wouldn’t benefit from the solar buy back - it adds tremendous value to the house.

Handle9

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#3415648 17-Sep-2025 17:27

Aucklandjafa:

hmmm, not really, no. When you install solar and batteries, not only are you still connected to the grid - but you feed energy back into the grid for others to use - it just means, because you’re self-sufficient, there is less strain on the grid.

That is not really true and doesn't usually help the major issue with the grid, which is peak load. The reality is the existing grid was never designed with local micro generation in mind so there are a lot of issues caused by mass adoption of solar, particularly around grid stability.

Stu1

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#3415705 17-Sep-2025 20:15

Jase2985:

Stu1:

xlinknz:

Hi all

Thank you for the replies.

Usage by volume give or take has doubled in the same 3 winter months since last year so the increase is unrelated to seasonal temperatures (We're Wellington)

I read that units can become inefficient especially 20 year old ones due to heat exchanger blockage, burner issues, thermostat/sensor issues and poor combustion. Our unit has never been serviced but servicing cost I assume is a lot less than a new unit

Has anyone found servicing an existing gas instant hot water unit made a difference to your bill? (I'm wary of replacement if a problem is not properly diagnosed!)

What costs have people experienced with replacing a gas instant hot water unit whether with has or electric?

interested in what costs you get back, I was chatting with plumbing world in the weekend in Wellington cost would be around 10 to 15k for an equivalent to an infinity . Where a new infinity around 3.5k massive difference

The person in the other thread did it for less than $9k installed and the gas connection removed

Each to their own.

I just read that pretty reasonable, worth shopping around

Aucklandjafa

542 posts

Ultimate Geek
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#3415706 17-Sep-2025 20:23

Handle9:

Aucklandjafa:

hmmm, not really, no. When you install solar and batteries, not only are you still connected to the grid - but you feed energy back into the grid for others to use - it just means, because you’re self-sufficient, there is less strain on the grid.

That is not really true and doesn't usually help the major issue with the grid, which is peak load. The reality is the existing grid was never designed with local micro generation in mind so there are a lot of issues caused by mass adoption of solar, particularly around grid stability.

sorry, can you explain how having a battery doesn’t help with peak load?

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