Instantaneous electric hot water systems

[westminster]

Our new property has no gas so would need LPG.

LPG is pretty expensive to use for an instantaneous system though so I'm trying to look into electric powered ones.

It will be the back up system to a Solar HWS and is just needed if the water isn't hot enough. We will also have solar panels for generating electricity

If we can get rid of needing LPG for water heating then we don't need gas/LPG at all (except for the bbq!)

Anyone here got notes, recommendations, ideas?

 

[Scott No Mates]

Consider electrical booster on solar hws. That should keep you out of cold water.

 

[bryn]

yeah, usually with solar you have electric boost- its not exactly instantaneous but if you have them switched (the best way) then if you flick it on you'll have hot water in 30 mins or so.

You can have them on a thermostat, even off-peak but be careful. If you use most of your hot water in the evening, the overnight booster will heat it back up before the sun gets a chance to do so the next day!

 

[Skuttles]

Hi Myf,
We have a 300l solar hws with electric backup. Works well imo, never without scorching hot water, though we are only a family of 3. No idea of running costs of the booster though.
Pm/call me if you have specific questions.

 

[bashworth]

For an effective instantaneous electric hot water you do need 3 phase as 240volts won't really cut it.

We have a Steibel Eltron unit that works well

 

[Michael Kelly]

Have you looked into heat pumps instead of solar? I don't know a lot about how they work but I think they draw heat from the air, apparently they are very efficient and don't need to use a back up very often.

 

[neK]

Ive read that heat pumps are absolutely terrible and to avoid them at all costs.

I've also got an Electric Instant in my IP.
It needs 3 phase power and its REALLY REALLY weak.
It will heat up enough water for ONE user only at any time.

 

[westminster]

Consider electrical booster on solar hws. That should keep you out of cold water.

yeah, usually with solar you have electric boost- its not exactly instantaneous but if you have them switched (the best way) then if you flick it on you'll have hot water in 30 mins or so.

You can have them on a thermostat, even off-peak but be careful. If you use most of your hot water in the evening, the overnight booster will heat it back up before the sun gets a chance to do so the next day!

Hi Myf,
We have a 300l solar hws with electric backup. Works well imo, never without scorching hot water, though we are only a family of 3. No idea of running costs of the booster though.
Pm/call me if you have specific questions.

We have solar with electric booster at the moment and hate it We have it on timer at 5am so that we can have hot morning showers but by the time the next person wants to use it (which might be evening showers or middle of the day after gym), the tank has refilled with cold water and it drives us nuts.

For an effective instantaneous electric hot water you do need 3 phase as 240volts won't really cut it.

We have a Steibel Eltron unit that works well

We will have 3 phase at the property. I have been looking into the Steibel ones. This one in particular

https://www.theenergyhub.com.au/ind...hase-instantaneous-electric-water-heater.html

Have you looked into heat pumps instead of solar? I don't know a lot about how they work but I think they draw heat from the air, apparently they are very efficient and don't need to use a back up very often.

I have but I don't really know much about them. I have seen this one

https://www.theenergyhub.com.au/ind...h-hot-water-heat-pump-with-smart-element.html

 

[sammmeee]

Funnily enough we had one just break down. Had to replace it. They said it was at least 30 years old????

Replaced with Super x instantaneous cost 825 fully installed. Basically the same one that lasted 30 years but new..

Not sure if that helps or not.

 

[bryn]

if you use instant electric during peak tariff, you'll think LPG is cheap!

What is your existing solar? If its not working correctly, go bigger. 400L+ tank and 4 panels. The biggest Apricus for example: http://www.apricus.com.au/domestic-hot-water/

Apricus are pretty much the best SHW on the market.

 

[INVSTOR]

^ My hubby said the same, "what size is your existing solar? You may need a bugger tank".

 

[Scott No Mates]

^ My hubby said the same, "what size is your existing solar? You may need a bugger tank".

R u from UnZud Invstor?

For an effective instantaneous electric hot water you do need 3 phase as 240volts won't really cut it.

The only time that I would recommend a 3 phase instantaneous unit is in a cafe. It is overkill otherwise.

 

[westminster]

if you use instant electric during peak tariff, you'll think LPG is cheap!

What is your existing solar? If its not working correctly, go bigger. 400L+ tank and 4 panels. The biggest Apricus for example: http://www.apricus.com.au/domestic-hot-water/

Apricus are pretty much the best SHW on the market.

^ My hubby said the same, "what size is your existing solar? You may need a bugger tank".

It is possible our current system is buggered or needs to be bugger

It is one of the solar HWS with the tank next to the panels (2 panels and std tank about 11yrs old) and I understand that newer ones are better.

As this is for the new house I'm happy to get a nice new solar HWS (probably with more panels) but I want something for back up that doesn't involve heating a whole storage tank of water like a booster does.

 

[INVSTOR]

R u from UnZud Invstor?



.

It is possible our current system is buggered or needs to be bugger

.

Oops, no. and I only had one drink with my late lunch.

 

[bryn]

but I want something for back up that doesn't involve heating a whole storage tank of water like a booster does.

What I would do is go standard apricus as I linked above, with electric booster- but setup the plumbing such that installing an instant gas unit would be easy. Then, if you find the solar doesn't cut it (unlikely IMO) then install the instant LPG booster.

instant lpg boost (4.7c/MJ) $8.36/hr for 26L @ 25 degree rise (Bosch 26ecoplus)

instant electric (27c/kwh) $2.60/hr for 7L @ 20 degree rise

So for a 1 minute shower at 10L/min with 10 degrees of boost, LPG would cost 2.2c.

So for a 1 minute shower at 10L/min with 10 degrees of boost, electric would cost 3.1c.

Electric is 40% more expensive.

 

[chank]

Does anyone have any ideas for a Hot Water System for my backyard Bungalow, which has a small bathroom and kitchenette. The problem is that it only has a total of 32Amps going into it from the main switchboard, and that is already running the power and lights and 15Amp mini stovetop.

Would any of the small electric instantaneous or storage units be suitable? They would need to be installed externally due to space restrictions.

Solar systems are too expensive for me, and I have ruled out gas as it would cost me thousands to run a gas pipe as there is no existing gas pipes.

 

[neK]

I know in Sydney if you have no gas, it would cost you $125 for AGL to run a line into your property.

Then its up to what the plumber charges to run the line from there to your desired location.

 

[tj22]

i'd just install a electric storage hwu you'd have to ask a sparky if it's possible.

if it's going to be rented out, i'd install a LPG continuous flow hwu. as there'd be less running of pipe work. downside more expensive to run but tenants would pay the bill..

 

[chrispy]

I installed an LPG instant Rheem HWS in my beach house. It is fantastic

I have two large tanks, so that when one runs out I switch over and get changeover of tank.

Chris