Instant Hot Water systems

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tweake

2391 posts

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#3017372 5-Jan-2023 14:57

mentalinc:

Not sure why you'd turn off one of the bottles?
They're designed to be both available so if you have all the hobs on, and someone having a shower/using hot water there is enough gas pressure available to meet the needs.
They should connect with a device that shows when the bottle is empty to reorder.

typically they are on a change over valve, which swaps to the other bottle when empty and displays an empty indicator. its doesn't run both at the same time.

some people don't have the auto change over valve, so when first bottle run out they run out. that way they know to order another. otherwise they tend to forget to check and end up with both empty. also for those with big burners or multiple heaters they can run both bottles at the same time as a single bottle can struggle to supply enough gas.

pih

649 posts

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#3017421 5-Jan-2023 15:13

tweake:
mentalinc:

Not sure why you'd turn off one of the bottles?
They're designed to be both available so if you have all the hobs on, and someone having a shower/using hot water there is enough gas pressure available to meet the needs.
They should connect with a device that shows when the bottle is empty to reorder.

typically they are on a change over valve, which swaps to the other bottle when empty and displays an empty indicator. its doesn't run both at the same time.

some people don't have the auto change over valve, so when first bottle run out they run out. that way they know to order another. otherwise they tend to forget to check and end up with both empty. also for those with big burners or multiple heaters they can run both bottles at the same time as a single bottle can struggle to supply enough gas.

Exactly. I turn one bottle off because I want to know when a bottle runs out and the best way to know is having the hot water run cold. That's the day we flick it over and order a new bottle. Not only that, but it gets me in the habit of turning off the new bottle and checking for leaks when it's delivered. The delivery guy usually leaves the valve open, but one time he also didn't tighten the hose properly and we lost some gas.

nic.wise

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#3017423 5-Jan-2023 15:20

Gas system here. Mostly cos we wanted to get the space back (very small house, 2 people). It’s a “correctly sized” Bosch unit. 17L/min or whatever the unit is??

Water consumption is our major concern as we are on tank water. Plus we already have a gas hob

If the gas HW broke id get a heat pump, outside tank one. And replace the hob with induction.

As it is we use ~3 45kg bottles a year. And yes, turn the spare off when it’s not being used. I’m fine having to switch it over when I’m in the shower (it’s always me…) to know when it’s finished.

Nic Wise - fastchicken.co.nz

insane

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#3017428 5-Jan-2023 15:27

I have a continuous gass system and went with the Rinnai EF24. Has an additional heat exchanger so it's more efficient - exhaust air is only about 50degrees vs the usual 100+.

Downsides:
- You waste a lot of water waiting for it to get warm.
- Doesn't work in a power failure
- Govt has declared war on anything gas

Upsides:
- Unlimited hot water
- Noticed a reduction in energy bills having switched from a very old 300L gas water cylinder.

For my living situation it makes perfect sense, but probably not if you don't need to use much hot water.

neb

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#3017438 5-Jan-2023 15:43

pih: I LOVE the ability to control errm, I mean gently discourage my teenager's tendency for ridiculously long showers.

Friend of mine had this problem with his teenage daughter taking 45-minute showers but it's simple to fix and doesn't need gas heating, he just shut off the outflow from the cylinder until he heard the squawk.

pih

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#3017460 5-Jan-2023 16:42

neb:
pih: I LOVE the ability to control errm, I mean gently discourage my teenager's tendency for ridiculously long showers.

Friend of mine had this problem with his teenage daughter taking 45-minute showers but it's simple to fix and doesn't need gas heating, he just shut off the outflow from the cylinder until he heard the squawk.

Totally. But there's something quite unique and satisfying about being able to say "Oh, that wasn't me, that was the timer". She actually gets it now and her showers are dramatically shorter with no yelling, not even grumbling. She can't change the timer and she knows I won't, so she adjusts her behaviour. It really was my most satisfying DIY project in the past few years, and it was relatively simple to achieve. It works no matter who is home, and can be bypassed by my wife and me if needed.

You could achieve the same outcome with a solenoid valve on the HWC, but that increases complexity somewhat.

Incidentally, we have had some issues recently with the septic system so - again, without much grumbling - I simply warned everyone and shortened the timer to 4 minutes to reduce the amount of water going in.

steve2222

498 posts

Ultimate Geek

#3017703 6-Jan-2023 10:09

insane: I have a continuous gass system and went with the Rinnai EF24. Has an additional heat exchanger so it's more efficient - exhaust air is only about 50degrees vs the usual 100+.

Downsides:
- You waste a lot of water waiting for it to get warm.
- Doesn't work in a power failure
- Govt has declared war on anything gas

................

I solved the 'doesnt work in a power failure' by using a basic 12v to 240v invertor plugged into the car. Neighbours probably wondered why we had the car iddling during a power failure, but at least we got a shower before going to work. This worked for us as our Infinity is plugged into an outside 240v power point (rather than hard wired). So just pulled the standard 240v plug from that and inserted it in the end of an extension cable running to the invertor where the car was parked.

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