Cost of continuous flow hot water system?

I would be wary of installing a new gas line with the volatility in the gas market at the moment – obviously impossible to predict but most projections have prices more than doubling in the next couple of years. Based on what price you’re quoting I assume you’re having to have gas connected or at least the pipes upgraded to allow for the high flow rate of gas required for instantaneous systems. I personally wouldn’t install anything gas any more.

If you have a largish house it’s worth considering multiple units – for instance if your bathrooms and kitchen are at opposite ends of the house you will lose a lot of heat (as well as waste water) on long pipe runs. You could consider a small point of use storage electric system for the kitchen – like a 25 or 50L tank you could keep under the sink, or else an instant electric. Then you could look at a solar or heat pump for the bathrooms (as close as possible). I personally would recommend a heat pump – the technology (the same as for an air conditioner) is well established overseas and there are plenty of great options available on the market now. The Edson Sanden (? something like that) one uses CO2 instead of a normal refrigerant and is great at the low temperatures we get in Canberra. There is some noise from the compressor unit so you don’t want to install right outside bedrooms or near neighbours. Some models can operate on off-peak too to save even more.
If you go for solar, evacuated tubes are a must in our climate and you could consider oversizing your panels to allow for less sun in winter (if necessary covering them over in summer to prevent overheating).

pajs said :

JC said :

Oh forgot to say with traditional tank heaters it has been the law for about 20 years that if you have a tank replaced it needs a tempering valve set to 60c. So even though it may be easy to up thermostat on a tank beyond this you will wont get super hot temps like some people are talking about as the tempering cable will mix in cold water for reduce it.

You should still be able to run a direct line from a higher-temperature supply to your kitchen sink, so long as the rest of the pipes have a tempering or thermostatic mixing valve between the supply and the use. The intention of the regulation is to stop bathroom scalds, not the washing up.

Yep – plumber quite legally set up for me a bypass system so that the bathroom hot water is 55% but the kitchen water is hot as.

If you install instant hot water in Canberra you have to have a system that preheats the water in a tank to a temperature that will allow a decent instant flow. There is no instant hot water system designed for near-zero water temperatures. You only usually find them in rentals, where the landlord doesn’t care whether the tenant gets a decent hot shower!

CheekyChicken said :

This is something we looked into with a great deal of interest.

We have a 20 place child care centre that needed a Hot water solution for 2 bathrooms and a kitchen.

Being a not for profit we needed to be absolutely certain that the unit we went with was first and foremost good for the environment and had the least amount of running costs and future maintenance / service costs.

Electric Tank = out of the question.
SOLAR hot water = Very expensive even with rebates, be cautious about what booster you have. other wise its just an electric tank on terrible winter days. or gas… with the added benefit of another gas bill.
Solar can sit there for 15 years potentially without any serious maintenance issues, but if it does not it can be very costly. Ongoing payback in our opinion was not worth the outlay as it is not as high a rebate as it used to be.

Gas / instant or similar. Cheap to buy, expensive to install depending on your installer.
The ACTEW shop as well as the government department that actually gives rebates for improving commercial premises advised against installing a gas unit as the projected cost of gas along with the initial purchase outlay and installation outlay were deemed not viable.

At point instant. = super popular in the UK mainly due to lack of ability to run pipes etc. AUST = the lucky country for that, easy timber framed houses generally. ( = poor heating and cooling retention but thats another topic)

They suggested solar or heat pumps.

We ended up getting a Quantum Energy heat pump. work down to some ridiculous minus temperature in winter, so no issues in Canberra.

Its their commercial unit, however they make a couple of residential units as well.

These things run with a tiny electric motor like a fridge basically and are WAY more efficient at giving your hot water day, night, sun shining or not… 🙂

There are rebates for these as well i believe.

The literature available online will show you comparisons between gas, elec, solar and the heat pumps so see for yourself whats better.

http://quantumenergy.com.au/products/heat-pump-vs-electric-solar-gas/
The ultimate hot water is geo thermal heat pump, but who has 20k to spend on hot water HAA HAA.

I installed a Dux heat pump HWS about 6 years ago. It was supplied without the “sub-zero chip” but when this was added it delivered hot water on the same basis as the old on demand electric I had for 10 years.
Electricity consumption decreased 30% immediately. The only maintenance problem I am aware of is replacement of the sacrificial anodes is required every 5 – 10 years. I used to replace elements in the old on demand electric every 2 – 3 years.
With heat pump air heating and cooling, double glazing, ceiling insulation and LED lighting I have reduced electricity consumption by half over 5 years.
I won’t contemplate gas due to a family tragedy caused by a faulty gas heater many years ago.

dungfungus said :

Be aware that Australia has signed massive delivery contracts for exporting gas and on current projections we will not meet them so domestic gas supplies will become even more expensive.
Once again, that filthy black stuff will save all civilised Australians who use electricity.

Yes we are very good at this, selling our resources overseas to make more money, while not caring about our own people. Look at fuel prices in countries that produce fuel. They keep them low by not selling everything overseas and buying it back.

Pros:
Never runs cold, handy if we have guests,
set the thermometer and 20 seconds later you’ve got hot water at the right temperature, no micro adjustment of the hot and cold taps for a minute or so.
bump the hot tap with your elbow and the temp doesn’t budge.

Cons:
Gas is going to get a lot dearer.
Can’t set the temp below 38 degrees or it cuts in and out, not good on hot days when you want a cooler shower.

Referring to the post above about the dishwasher:
We had our old one replaced recently and the installer said we should only connect it to cold water.
Hot water entering a cold dishwasher expands and contracts the seals quickly, reducing their working life.

This is something we looked into with a great deal of interest.

We have a 20 place child care centre that needed a Hot water solution for 2 bathrooms and a kitchen.

Being a not for profit we needed to be absolutely certain that the unit we went with was first and foremost good for the environment and had the least amount of running costs and future maintenance / service costs.

Electric Tank = out of the question.
SOLAR hot water = Very expensive even with rebates, be cautious about what booster you have. other wise its just an electric tank on terrible winter days. or gas… with the added benefit of another gas bill.
Solar can sit there for 15 years potentially without any serious maintenance issues, but if it does not it can be very costly. Ongoing payback in our opinion was not worth the outlay as it is not as high a rebate as it used to be.

Gas / instant or similar. Cheap to buy, expensive to install depending on your installer.
The ACTEW shop as well as the government department that actually gives rebates for improving commercial premises advised against installing a gas unit as the projected cost of gas along with the initial purchase outlay and installation outlay were deemed not viable.

At point instant. = super popular in the UK mainly due to lack of ability to run pipes etc. AUST = the lucky country for that, easy timber framed houses generally. ( = poor heating and cooling retention but thats another topic)

They suggested solar or heat pumps.

We ended up getting a Quantum Energy heat pump. work down to some ridiculous minus temperature in winter, so no issues in Canberra.

Its their commercial unit, however they make a couple of residential units as well.

These things run with a tiny electric motor like a fridge basically and are WAY more efficient at giving your hot water day, night, sun shining or not… 🙂

There are rebates for these as well i believe.

The literature available online will show you comparisons between gas, elec, solar and the heat pumps so see for yourself whats better.

http://quantumenergy.com.au/products/heat-pump-vs-electric-solar-gas/
The ultimate hot water is geo thermal heat pump, but who has 20k to spend on hot water HAA HAA.

pajs said :

JC said :

Oh forgot to say with traditional tank heaters it has been the law for about 20 years that if you have a tank replaced it needs a tempering valve set to 60c. So even though it may be easy to up thermostat on a tank beyond this you will wont get super hot temps like some people are talking about as the tempering cable will mix in cold water for reduce it.

You should still be able to run a direct line from a higher-temperature supply to your kitchen sink, so long as the rest of the pipes have a tempering or thermostatic mixing valve between the supply and the use. The intention of the regulation is to stop bathroom scalds, not the washing up.

That’s what happens in my house.

JC said :

Oh forgot to say with traditional tank heaters it has been the law for about 20 years that if you have a tank replaced it needs a tempering valve set to 60c. So even though it may be easy to up thermostat on a tank beyond this you will wont get super hot temps like some people are talking about as the tempering cable will mix in cold water for reduce it.

You should still be able to run a direct line from a higher-temperature supply to your kitchen sink, so long as the rest of the pipes have a tempering or thermostatic mixing valve between the supply and the use. The intention of the regulation is to stop bathroom scalds, not the washing up.

Oh forgot to say with traditional tank heaters it has been the law for about 20 years that if you have a tank replaced it needs a tempering valve set to 60c. So even though it may be easy to up thermostat on a tank beyond this you will wont get super hot temps like some people are talking about as the tempering cable will mix in cold water for reduce it.