Beware Heatpump external unit rusting

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linw

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#318488 23-Jan-2025 13:55

We 'inherited' a Fujitsu heat pump 5.5 years ago and it wasn't by any means new then. Yesterday it was really hot in Porirua (yes we were surprised as well!) so I switched it to cool mode. But the outside unit was loudly tick ticking so I turned it off. I got the top off and the fan was certainly hitting the ring around it when I moved the fan by hand.

Long and short, a vertical support bar that held the fan motor was rusted through at the bottom end, so the motor was moving. The motor's shaft was rusted as well.

Perhaps a warning to check that outside unit, but, of course, all geekzoners would already have been doing this.

Raises an interesting question as to how one could stop this rusting and still keep air intake slots open. Rub grease over all steel bits every so often?

So, a new pump for us. Harvey Norman have Panasonic ones. I was looking at the 6KW RZ50AKR. Anyone had Panasonics or reports on them?

TIA.

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#3334759 23-Jan-2025 14:04

We live by the ocean and had a new Fujitsu heat pump installed 12 months ago.

Before install, I checked with Fujitsu who confirmed five year warranty does not cover external rust.

Installer advised to wash the exterior unit regularly (every couple of weeks) with fresh water and mild detergent.

timmmay

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#3334769 23-Jan-2025 14:43

I had a Panasonic ducted heat pump 3 or 4 year ago. The external unit and unit in the roof were so loud we had them take it away and replaced it with a Daikin. The Daikin outdoor unit you can only hear when you're within 1-2 meters of it, the Panasonic we could hear from 10 - 12 meters away.

I suggest Daikin and Mitsubishi as best quality, we had Fujitsu for a decade that worked well but we replaced with a ducted system. They may be much better now, and the high wall units may be great, I have no idea, but I wouldn't chance it personally. Make sure you look at the volume specs, and ask people who have recent Panasonic heat pumps how they are, and ideally have a listen to them yourself before purchasing.

I basically won't buy anything made by Panasonic any more unless it's widely reviewed as being excellent. Heat pumps, microwaves, headphones, anything. They do a lot of things and not all of them well.

dafman

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#3334784 23-Jan-2025 15:31

timmmay:

... we had Fujitsu for a decade that worked well but we replaced with a ducted system. They may be much better now, and the high wall units may be great, I have no idea, but I wouldn't chance it personally.

We are only 12 months in with our Fujitsu, but couldn't be happier. We do not hear the external unit at all from inside the house, internal noise is minimal in quiet mode and the unit does a great job of regulating temperature.

The wifi app is a breeze to use for adjusting temp, fan speed and direction, scheduling auto on/off - plus the ability to turn the unit on remotely when out and about. I don't think I have ever picked up the physical controller from its wall bracket!

linw

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#3334796 23-Jan-2025 16:35

Thanks for your posts. Appreciated.

Will check with a company here in Porirua who deal with Fujitsu.

Being in a seaside place must be worrying with the outdoor unit. In my meandering I saw something about some co. advertising to treat the unit.

Another one was touting the benefits of ACF50. Sounded good stuff. Saw Bunnings had it but maybe it was Australia as my Bunnings didn't have it. Saw this as well.

Downunder Pilot Shop

https://pilotshop.co.nz › products

ACF-50 Anti Corrosion Spray - 13oz - Pilot Shop

This 13oz spray is recommended by numerous aircraft makers around the globe and is supposed to be the best anti-corrosion spray available. Used by US Navy on all aircraft based on aircraft …

Brand: ACF-50

Availability: In stock

dafman

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#3334927 23-Jan-2025 20:41

linw:

Thanks for your posts. Appreciated.

Just sent you a PM re my heat pump install.

Eva888

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#3334987 24-Jan-2025 08:48

Also near the sea. Would it be ok to use the ACF spray through the grills and just let it go everywhere or would it need to be targeting specific parts to avoid electrics. Wondering if unit would need a wash first before spraying. Am always nervous hosing into the unit.

One expensive lesson learned is to make sure the outside unit is off the ground sitting on a stand. One of our installers didn’t add the stand, thus was sitting close to the ground. The gas container rusted through,leaked gas and not repairable. Installer was a cowboy.

Rickles

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#3335001 24-Jan-2025 09:56

My daughter had two new units installed 7 months ago (Hutt Valley) and after significant research (2 spreadsheets 😃) selected Mitsubishi units.

Definitely very quiet, even when standing alongside the outside motors. The wifi app is excellent too.

If you want to talk to an installer, check out Moore Energy Limited 13 John Street Trentham, Upper Hutt, +64274448165 www.mooreenergy.co.nz

Mike Moore was very thorough, knowledgeable and happy to discuss options at length.

Mighty Ape

Shop now on Mighty Ape (affiliate link).

neb

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#3335151 24-Jan-2025 13:22

timmmay: I had a Panasonic ducted heat pump 3 or 4 year ago. The external unit and unit in the roof were so loud we had them take it away and replaced it with a Daikin. The Daikin outdoor unit you can only hear when you're within 1-2 meters of it, the Panasonic we could hear from 10 - 12 meters away.

+1 for the Daikin, same results as you, Panasonic was quite loud, Daikin you need to get quite close before you can hear it's running. This is, admittedly, in comfort mode which minimises noise.

neb

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#3335153 24-Jan-2025 13:29

linw: Downunder Pilot Shop https://pilotshop.co.nz › products ACF-50 Anti Corrosion Spray - 13oz - Pilot Shop

Ouch, that's expensive! Sounds a lot like Boeshield, which is equally expensive.

You need to check what you're applying and what it's being applied to, Boeshield works by forming a wax-like coating over a period of several days, a bit like Cosmoline, that provides good protection but looks ugly and prevents any movement of what it's coating. If you're going to do this you may as well just paint it with Penetrol (also takes several days to cure) which forms a similar protective coating.

If you're protecting something that you don't want covered in a hard waxy coating, there are various silicone-based sprays that also work well and don't prevent movement, as well as being vastly cheaper. There's a ton of YT videos where people coat bare steel with various things and spray salt solution on them and show the results, you can check those if you want to get a better idea of the options.

linw

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#3335156 24-Jan-2025 13:32

Re spraying for rust protection, I would not suggest bulk spraying in case it affected bits that shouldn't be sprayed.

From what I saw in mine, it would have been useful to have painted the air inlet slots and the base area inside, especially where the vertical arm that held the motor was bolted at the bottom. This latter was rusted out allowing the motor to move.

But, hey, if in doubt, get a pump maintenance person to help out!

timmmay

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#3335219 24-Jan-2025 15:04

neb:

timmmay: I had a Panasonic ducted heat pump 3 or 4 year ago. The external unit and unit in the roof were so loud we had them take it away and replaced it with a Daikin. The Daikin outdoor unit you can only hear when you're within 1-2 meters of it, the Panasonic we could hear from 10 - 12 meters away.

+1 for the Daikin, same results as you, Panasonic was quite loud, Daikin you need to get quite close before you can hear it's running. This is, admittedly, in comfort mode which minimises noise.

I've just seen a message from someone who installs Air Conditioners in Australia for a living. He chose Panasonic for his ducted system, along with AirTouch, because of filtration and they work well. His second was Mitsubishi and third Daikin, but he didn't say why.

I personally would only buy Daikin or Mitsubishi unless there was a very, very good reason to get another brand, and I'd researched it very well particularly noise.

neb

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#3335234 24-Jan-2025 15:50

The one downside with Daikin is that the WiFi controllers are outrageously expensive extras and badly implemented, each one sets up an AP so if you've got five head units you've got five APs broadcasting constantly.

timmmay

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#3335238 24-Jan-2025 15:58

True about WiFi. I never noticed the AP but I can see it on my newest Daikin with WiFi card. The card cost me $150.

dafman

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#3335253 24-Jan-2025 16:15

The WiFi on our Fujitsu is a breeze to use, I'd recommend the brand on this feature alone! From memory, was around $200.

timmmay

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#3335255 24-Jan-2025 16:33

I use home assistant to control all my heat pumps, including the 15 year old one with an IR blaster, ducted which comes with WiFi, and new Daikin with the wifi card. They all work fine, IR obviously being slightly less reliable than wifi.

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