Looking at replacing old hotwater tank with Rinnai Heatpump Hotwater Tank, any Rinnai opinions?

Forums › Home Workshop DIY › Looking at replacing old hotwater tank with Rinnai Heatpump Hotwater Tank, any Rinnai opinions?

Devilz

9 posts

Wannabe Geek

#315555 25-Jul-2024 13:51

Ive got a bargain price for a Rinnai HydraHeat Hot Water Heat Pump from a friend and thinking of buying one to replace the current hotwater cylinder which really needs replacing due to age... but cant seem to find any reviews or comments from any owners (might be to new a model to have sold many?)

Anyone out there have any exerpience with them? noise levels etc (they say 45db but you know how companies like to advertise their best numbers only)

I did read somewhere that the heatpump that sits on top is a Midea/China made unit? Which doesnt give me great confidence for reliability over 5 years when the warranty runs out, and being a unit that sits on top of the tank getting a replacement after 5 years thats a direct replacement and fits with the tank could be a problem compared to the external split heatpump type models out there.

Wheelbarrow01

1724 posts

Uber Geek

Trusted

Chorus

#3264473 25-Jul-2024 23:46

I had a look at the Rinnai website and it states that the heatpump unit is "modular" and bolts on top of the matching water cylinder. So it seems to me that as long as Rinnai keeps producing the model line, you should be able to buy a replacement heat pump module that just bolts onto your existing cylinder. I'd be questioning how much such a replacement might cost before committing to the spend. The entire unit has an RRP of $6499. But you don't want to find out later down the track that a replacement of the heatpump module by itself is almost the same as buying an entirely new system....

My two cents: At that $6499 price point, you'd certainly want your existing hot water system to be fully end of life before considering it.

Assuming it's a reliable system, I can see the energy saving advantages, particularly if you were to bundle it with a PV solar array (which due to the efficiency of the heatpump water heater, could probably be made smaller than average).

Note: I have no real world experience with this type of system whatsoever - we have a modern mains pressure electric hot water cylinder at home that serves us well. At the bach we have a Rinnai Infinity instant gas system (on 45kg bottles) which also suits our needs perfectly - instant hot water the moment we need it, but zero energy cost when we are not there.

ShinyShrimp

1 post

Wannabe Geek

#3279318 5-Sep-2024 16:13

Hi @Devilz I'm also looking at getting a Rinnai Hydraheat would you mind letting me know where you got a good price for it? Did you end up installing and what's your experience so far?

Devilz

9 posts

Wannabe Geek

#3279398 5-Sep-2024 21:55

ShinyShrimp:

Hi @Devilz I'm also looking at getting a Rinnai Hydraheat would you mind letting me know where you got a good price for it? Did you end up installing and what's your experience so far?

I actually just got it installed today, so perfect timing, apart from my experience so far is aout 8 hours runtime :) I got it from a friend who works for Rinnai so didnt get it through the usual retail channels (only reason I went for it really as otherwise it would have been to much for my wallet) probably best to phone around a few places to get the best price you can (Auckland home show sometimes have discounts if you up this way this weekend I think?)

It looks great mounted outside and the heatpump part is reasonably quiet as well, got it mounted just to the side of the single pane kitchen window and cant hear a thing when the fans going, after a month of running ill give the power bill a looking at to see if it was worth it in the end.

Its got options to enable heatpump only mode if you dont need the 275litres of water heated up to quickly, so we'll see if ill switch it to that mode after a while to save more power, currently set to standard mode which can use the normal element heater to bump up the temperature quicker if you use a lot of water at once.

I assume theyre worth it the more hot water your family usually uses, so the more showers/baths the more money youll end up saving per monthly power bill (and also depending how many years youll live at the residence to get your savings back)

Its only me, the missus and the toddler at the house at the moment so the total hot water usage isnt massive compared to larger families (we went from a 170L tank which was more than enough water to the 275L due to the heatpump not needing to work as hard to keep more water warm I guess) so the monthly savings wont be huge but I needed a new cylinder anyway so thought may as well get the best I could for the price at the time even it was a little overkill for what we needed as we'll be here for a few years and should hopefully get the extra cost back as power savings by that time if it works as its intended to.

Fingers crossed it works for years without issues but time will tell

boland

545 posts

Ultimate Geek

#3348783 28-Feb-2025 20:26

Devilz:

ShinyShrimp:

Hi @Devilz I'm also looking at getting a Rinnai Hydraheat would you mind letting me know where you got a good price for it? Did you end up installing and what's your experience so far?

I actually just got it installed today, so perfect timing, apart from my experience so far is aout 8 hours runtime :) I got it from a friend who works for Rinnai so didnt get it through the usual retail channels (only reason I went for it really as otherwise it would have been to much for my wallet) probably best to phone around a few places to get the best price you can (Auckland home show sometimes have discounts if you up this way this weekend I think?)

It looks great mounted outside and the heatpump part is reasonably quiet as well, got it mounted just to the side of the single pane kitchen window and cant hear a thing when the fans going, after a month of running ill give the power bill a looking at to see if it was worth it in the end.

Its got options to enable heatpump only mode if you dont need the 275litres of water heated up to quickly, so we'll see if ill switch it to that mode after a while to save more power, currently set to standard mode which can use the normal element heater to bump up the temperature quicker if you use a lot of water at once.

I assume theyre worth it the more hot water your family usually uses, so the more showers/baths the more money youll end up saving per monthly power bill (and also depending how many years youll live at the residence to get your savings back)

Its only me, the missus and the toddler at the house at the moment so the total hot water usage isnt massive compared to larger families (we went from a 170L tank which was more than enough water to the 275L due to the heatpump not needing to work as hard to keep more water warm I guess) so the monthly savings wont be huge but I needed a new cylinder anyway so thought may as well get the best I could for the price at the time even it was a little overkill for what we needed as we'll be here for a few years and should hopefully get the extra cost back as power savings by that time if it works as its intended to.

Fingers crossed it works for years without issues but time will tell

Hi @Devilz I came across this topic, we've been quoted a good price for the Rinnai as well. What are your thoughts now after half a year?

Devilz

9 posts

Wannabe Geek

#3348795 28-Feb-2025 21:59

So far its still working without an issue which is one thing :)

Its quiet enough when the heatpump is actually running to warm up the water to not be noticed

My power bills have definetly been less on average per month compared to the previous year but only usually about $30-$40 on average if that but with a toddler needing more frequent baths and hand washing/splashing/playing with warm water, hotwater usage probably has risen in the last year as well so bit hard to calculate exactly how much it would be saving if things has stayed the same water use wise

Just got an email from the power company yesterday saying power prices are going up and they extimate my power bill be an extra $30 a month when that happens :P

So as soon as you start using less power and saving money the power companies find a way to just get that money back again... which kinda sucks!

I might try enabling the function of the heater to lower the normal temp down to 50 degress instead of 60 and see if that helps save another $ a month (it has a function to stay at 50 degrees and every so often heat the water to 60 to kill any bacteria that might grow below 60 degrees)

Or if power bills keep climbing for the power companies profits I may just have to get that new roof and some solar panels next...

WWHB

35 posts

Geek

#3348913 1-Mar-2025 09:27

Here is my 2 cents on this.
I install lots of hot water heat pumps, close to 1 a week. You shouldn’t have to use the element as this defeats the purpose of getting one installed. There is no power savings from having the element running. The best models on the market don’t even have back up elements. If I install a model with a back up element, when installing I set them up in heat pump only mode. If they have extra people staying they can boost them to speed up recovery. With using the boost function it is a one off use of the element.

I personally have installed a model that requires no back up element at all and got savings of approx $100 a month on my power bill ( Family of 4)

boland

545 posts

Ultimate Geek

#3348962 1-Mar-2025 13:59

WWHB:

Here is my 2 cents on this.
I install lots of hot water heat pumps, close to 1 a week. You shouldn’t have to use the element as this defeats the purpose of getting one installed. There is no power savings from having the element running. The best models on the market don’t even have back up elements. If I install a model with a back up element, when installing I set them up in heat pump only mode. If they have extra people staying they can boost them to speed up recovery. With using the boost function it is a one off use of the element.

I personally have installed a model that requires no back up element at all and got savings of approx $100 a month on my power bill ( Family of 4)

Which model would you recommend? Do you install split systems or integrated, or both? I've read integrated are less efficient due to lack of space / air inlet.

Sharesies

Trade NZ and US shares and funds with Sharesies (affiliate link).

tweake

2391 posts

Uber Geek

#3348967 1-Mar-2025 14:43

boland:

Which model would you recommend? Do you install split systems or integrated, or both? I've read integrated are less efficient due to lack of space / air inlet.

its not so much about lack of space but where its installed and the climate your in. a lot of info on the net is overseas with different climates. if you put integrated one inside a house in a cold climate, your taking heat from the house and then heating the house up with the home heating system, and that two step can be less efficient or effectively an expensive gas hot water system if the house is gas heated. if your in a warm climate and normally running aircon most of the time then it works in your favor.

if your in a mild climate and put it outside, what you loose in heat is made up for by being cheap to heat. there is also no issues with space/airflow.

mattwnz

20163 posts

Uber Geek

#3348974 1-Mar-2025 15:07

Devilz:

So as soon as you start using less power and saving money the power companies find a way to just get that money back again... which kinda sucks!

With them putting up the daily rate for low power users, as well as the unit rates, I will soon be paying more just for the connection, than for the power I use.

PolicyGuy

1727 posts

Uber Geek

ID Verified

Lifetime subscriber

#3349024 1-Mar-2025 15:37

mattwnz:

With them putting up the daily rate for low power users, as well as the unit rates, I will soon be paying more just for the connection, than for the power I use.

Which is entirely economically rational from your providers' point of view.

It costs your local Lines Company pretty much the same to provide a connection to your house, whether you're consuming virtually nothing, or running a relatively large load 24/7. Therefore you should pay the same daily lines charge.
It costs your electricity retailer exactly the same amount to read your meter, then calculate and send you a bill, whether or not you used a single kWh of 'their' electricity or 25,000 kWh, so their portion of the daily charge should be the same too.

BTW, I've paid more for my connection charge than my nett energy charge for most of the summer months the last three years, but I'd rather pay that money than put up with the expense, effort and risk of taking my house off grid.

boland

545 posts

Ultimate Geek

#3349025 1-Mar-2025 15:38

tweake:

its not so much about lack of space but where its installed and the climate your in. a lot of info on the net is overseas with different climates. if you put integrated one inside a house in a cold climate, your taking heat from the house and then heating the house up with the home heating system, and that two step can be less efficient or effectively an expensive gas hot water system if the house is gas heated. if your in a warm climate and normally running aircon most of the time then it works in your favor.

if your in a mild climate and put it outside, what you loose in heat is made up for by being cheap to heat. there is also no issues with space/airflow.

Thanks. We're in the Wellington region so mild climate. Thinking to get an integrated system, outside. But also still considering a split system, not sure yet.

Which brand / type do you usually install?

tweake

2391 posts

Uber Geek

#3349029 1-Mar-2025 15:48

boland:

Thanks. We're in the Wellington region so mild climate. Thinking to get an integrated system, outside. But also still considering a split system, not sure yet.

Which brand / type do you usually install?

i looked at this recently after my cyl leaked. for me the extra cost wasn't worth it due to the small amount i use so i went with standard electric.

WWHB

35 posts

Geek

#3349094 1-Mar-2025 22:49

boland:

WWHB:

Which model would you recommend? Do you install split systems or integrated, or both? I've read integrated are less efficient due to lack of space / air inlet.

I install both all in one and split. The big thing that makes the difference to the performance is the gas used.

R744 - this is what is used in the best systems out there, these are whisper quiet and have fast recovery. Sanden Ecoplus (approved installers only) and Reclaim are the best systems out there. These are both split systems and do not need an element

R290 - This would be the next best choice with a lot of choices from different manufacturers. Systems using this gas are available in both split and all in one. A good all in one choice here would be the Apricus AiO. Rheem and Rinnai both do systems using this gas as well. Envirosun is a newer brand using R290, and is very well priced.

R134a - This is the least environmentally friendly option but would still be a lot more efficient than a standard hot water cylinder.

I have a Sanden system myself at home and in my opinion it’s probably the best system out there at this moment.
You don’t always get what you pay for, some systems you would think are high end use R134a.
I would advise against anything made by Midea (including Ecospring). I used to install these for a previous employer and they just don’t last, well the heat pump doesn’t.

I used to have the older Rinnai Split system and it failed at 7 years old, I got no back up service from Rinnai which was extremely disappointing as a installer and has put me off trying one of their new Hydraheats.

WWHB

35 posts

Geek

#3349095 1-Mar-2025 22:53

An Intergrated or All in One system shouldn’t be installed inside, the air that comes out them is very cold. It may seem like a bonus in a hot summer but in winter your house would be like a fridge.

Sanden and Reclaim systems work well even at sub zero temperatures

tweake

2391 posts

Uber Geek

#3349177 2-Mar-2025 11:04

btw R744 is co2 and R290 is propane.