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Heat pumps v gas hot water systems - any thoughts?

Created by Juddy Juddy  > 9 months ago, 4 May 2015
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Juddy
Juddy

WA

1103 posts

4 May 2015 11:03am
The gas (storage) hot water system is looking like it’s on its’ last legs – it’s about 13yrs old.

We’re looking to replace it but I’m interested to hear from anyone who’s had any experience with heat pump hot water systems, especially if you live in Perth?

cheers for your advice....
Macroscien
Macroscien

QLD

6808 posts

4 May 2015 1:21pm
Did you consider solar hot water?
Juddy
Juddy

WA

1103 posts

4 May 2015 11:24am
no, just looking @ options currently....

(edited previous post - misread it thinking you were talking about PV, not solar HWS)....
touch107fm
touch107fm

WA

78 posts

4 May 2015 12:42pm
We are in WA and the house we bought had solar hot water system already installed. Have to say it awesome, we had a gas system in the past and was starting to get expensive.
Only cost for solar is the replacement of the sacrificial anode.
seanhogan
seanhogan

QLD

3424 posts

4 May 2015 2:46pm
+1 for solar HW!! had one installed on my roof, never looked back, so comfy to use with good taps compared to gas.

on a side note you can keep your wine in the same room as the heat pump as it produces cold on the outside !
Sailhack
Sailhack

VIC

5000 posts

4 May 2015 3:28pm
Solar with heat pump. We put an instantaneous gas HWS in about a decade ago and I can't fault it. Solar wasn't as good then as it is now otherwise we would've gone that way.
Ben 555
Ben 555

NSW

456 posts

4 May 2015 3:56pm
Have gone from Solar with heat pump to heat pump only.....sadly.

The system on the old house was faultless. We installed the system and worked out the system broke even with the cheaper options at about year 3 - we had it for 5 before we sold

The externally located heat pump system on the new place is a few years old but prone to blowing the controller (twice).
pweedas
pweedas

WA

4642 posts

4 May 2015 1:57pm
The heat pumps are very efficient. Usually a coefficient of production of around 3 to 4. It goes down a bit as the water temperature increases, but up to 60deg C it is up around 4.
The problem is in the initial expense. They are (or were, I haven't checked them recently) very expensive.
I see a few places up north are using them. I don't know why when it's so sunny up there you would think solar would be the obvious choice.

I was thinking maybe use solar/electric with some solar panels to help supply the electricity when needed.
Solar panels can still supply significant power even when it's a bit shady.

I like the idea of the heat pump from the point of view of the technical cleverness of them but I think they might lack a bit in the practical aspects.
As with all air conditioners (heat pumps) they have a limited life and are expensive to replace.
It means when either the water tank springs a leak or the heat pump wears out, you have to replace the whole lot.
I know they say you can just replace parts of it if it packs up, but the reality is, when it does pack up they will say it's cheaper in the long run to replace the whole lot. A bit like replacing car parts really. These days you mostly just junk the lot and buy another one. (Well some people do,.. but I don't. . )
TurtleHunter
TurtleHunter

WA

1675 posts

4 May 2015 2:05pm
solar with electric backup works a treat. Heat pumps are just too complicated especially if it's just backing up your solar. Gas backup for the solar would of been handy this weekend with no power and cloudy cold weather but then how often do you get a cyclone in may
patsken
patsken

WA

713 posts

4 May 2015 4:09pm
Single storey house or two storey ???

Solar panels on a second storey roof should be more expensive to install....

I have a Bosch instantaneous gas heater (with pilot flame - the auto start one I had in the past was a pain in the a..e due to tiny spiders or bugs regularly nesting in the warm gas jet and blocking it up at unfortunate times). Simple to use, cheap to buy and cheap(ish) to run unless you have teenage daughters. The pilot jet sometimes blows out but generally only once or twice a year and mine is exposed to the seabreeze side of the house. It's also easy to adjust for the temperature changes over the seasons.
Pitbull
Pitbull

WA

1267 posts

4 May 2015 4:59pm
I've been using an instantaneous gas system for years (Rinnai). Small neat outdoor unit with a pilot light which kicks in when a certain volume of water passes through it. Brilliant. Cheap to run. You get charged for what you use.
teatrea
teatrea

QLD

4177 posts

4 May 2015 7:37pm
Ifyou live in perth go roof top solar ,simple last a long time.heat pumps unreliable costly to repair.
dantren
dantren

QLD

307 posts

4 May 2015 9:27pm
There is nothing hi tech about the heat pump, it's just a window rattler on reverse cycle.
The few I've seen are quite noisy, and motors are D.O.L, not dc inverters.
Don't get me started about pcb's

I like the Turtlehunter's post.

p train
p train

VIC

2629 posts

4 May 2015 11:22pm
I am going with solar hot water, I have been told that solar hw puts out mains pressure hot water.

Can someone confirm this?
Katut
Katut

50 posts

4 May 2015 9:28pm
I also had a storage hot water system about 5 years ago,
had some reno's done and coverted to a Rinnai instantaneous system
bloody brillant, never run out of hot water, As Pitbull said, pay for what you use.
landyacht
landyacht

WA

5921 posts

4 May 2015 9:33pm
Select to expand quote
p train said..
I am going with solar hot water, I have been told that solar hw puts out mains pressure hot water.

Can someone confirm this?


we are on our second solar edwards system. first lasted 18 years. replaced as the older generation panels were getting dodgy. on a subzero morning there would be pressure surges through the mains that the panels couldnt handle. new gen with glycol jackets are way more efficient. almost too hot , so i would recommend regular checks of the overheat valve.
here in kal dont use ceramic lined steel storage tanks as they have to shipped by road and develop microcracks and give very poor life.
solar edwards have stainless. so great.
the new type of Vacumn tube solar uses electricity to pump the water, so i cant see the point.
in the adverts they claim the lowest electricity use of any storage system, but the fine print that flashes up says tested in summer in Broome. surely in broome you wouldnt even bother with a booster on a regular solar?
gs12
gs12

WA

421 posts

4 May 2015 10:04pm
Select to expand quote
Juddy said..

We’re looking to replace it but I’m interested to hear from anyone who’s had any experience with heat pump hot water systems, especially if you live in Perth?

cheers for your advice....




we've had Stiebel Eltron heat pump for about two years (in Perth), 300l capacity, (we also have PV which fully covers the heat pump needs, so hardly ever pay for hot water).
You may want to search through whirlpool greentech forums, there is ton of posts on exactly this topic (http://forums.whirlpool.net.au/forum/143).
We've had no problems with Stiebel, it is little noisy, so be careful about the location, you can get noise reduction hood for it (mine is DIY). Ours runs between 3 (summer) and 8 hours per day (winter), depending on how much hot water we use. We have high hot water consumption and are yet to run out of hot water.

Stiebel recommends to have the sacrificial anode checked/replaced every 12 months, I had it checked after the first year and it was fine, the technician said to leave it for another two years before checking again (in Perth hills, if that makes any difference with regards to water quality).
Other heat pump brands with good reputation on whirlpool are Sanden and Siddons. There are few others with mixed reviews, whirlpool is your friend.
dmitri
dmitri

VIC

1040 posts

5 May 2015 12:05am
We just got quotes for replacing our old hot water system.
$2000 for Rennai and $2000 after government rebate for a solar with the same rennai back up.
I think we'll just go for Rennai. We had it in the past in our old place and it was great.
All those panels will be just extra hussel I reckon. For what savings ? What if the roof needs to be repaired ?
cauncy
cauncy

WA

8407 posts

4 May 2015 10:07pm
Been doing a fair bit of research with sparky and plumber for my new house,
Quantum heat pump, $3,700, approx$400 per year running cost
Similar for solar inc booster usage for winter
The sparky has a standard hwsu on a timer
Unit cost $800, $95 last quater power use
The more exspensive options need to run trouble free for a long time to break even, then if you have a failure out of warranty you'll be behind, also will someone give you an extra $3700 if you sell because you've got a heat pump or solar? The main reason I was thinking heat pump was to use the cold air which they produce and vent into the house, cheaper to hose the missus off in the back yard juddy
cisco
cisco

QLD

12364 posts

5 May 2015 1:31am

If you install a heat pump HWS in your garage, it will become an air conditioned garage. How is that for getting the best out of your energy buck???
pweedas
pweedas

WA

4642 posts

5 May 2015 2:58pm
That's only a good idea in summer when you might like a nice cool garage.
Wot happens in winter when you go to get in the car and find the windscreen is all iced up? huh? Well????
Hardcarve1
Hardcarve1

QLD

550 posts

5 May 2015 9:52pm
I'm still to decide between the heat pump and solar but one thing comes to mind is recovery. Heat pumps are very quick to recover from over use but solar are slow. But I can only think of a few times I have ever emptied a HW of hot wat
cisco
cisco

QLD

12364 posts

5 May 2015 11:22pm
Select to expand quote
pweedas said..
That's only a good idea in summer when you might like a nice cool garage.
Wot happens in winter when you go to get in the car and find the windscreen is all iced up? huh? Well????


Uuummmm. Life is great in the sunshine state or something like that.
cauncy
cauncy

WA

8407 posts

5 May 2015 10:50pm
Select to expand quote
cisco said...

If you install a heat pump HWS in your garage, it will become an air conditioned garage. How is that for getting the best out of your energy buck???


Wouldn't work so efficient, they prefer a moderate temperature, so having them in a cold climate wouldn't be that great
I've also noted that as they basically suck air in having them in coastal regions or on in protected areas of the house can lead to failures due to salt air
They are temperamental to surrounding temperatures as we fitted 3 inline at dirk Hartog island for the accomadation , we found the middle unit was being starved from the 2 outer units so wasn't operating at the same level as outer units
Buster fin
Buster fin

WA

2597 posts

6 May 2015 6:15am
I paid a bit more for a 600 litre tank for my solar HWS with gas back up. It's great but the gas comes on whether it's needed or not. I now turn off the gas unless sits been cloudy for a couple of days in a row.
gas bill looks very svelte.
no lack of hot water issues.
seanhogan
seanhogan

QLD

3424 posts

6 May 2015 8:33am
probably/surely a default but a close mate had half his unit destroyed (by steam and flooding) by the explosion of his heat pump.
Buster fin
Buster fin

WA

2597 posts

6 May 2015 9:47pm
Oops. 400 ltr.
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