Cleaning heatpump outdoor unit

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gzt

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#319605 13-May-2025 10:16

I've been putting this off for a while. I see there are cans of spray on hose off cleaner available from bunnings. Mine is a Hitachi if it makes any difference.

Have you cleaned your own external unit? any tips?

Mine has 5+ years of service. I clean the internal unit yearly.There are no current issues.

ANglEAUT

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#3372696 13-May-2025 10:40

Good question. following with interest

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tweake

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#3372732 13-May-2025 11:37

if your referring to the supercell spray on cleaner, its really meant for indoor coils. its basically just a light detergent with fragrance so it makes the house smell nice.

dishwashing detergent will do fine for the outside coils.

really what you want is the foaming detergents. i would look at crc coil cleaner. otherwise you can go get the real pro stuff at commercial refrigeration companies, but you have to be careful with what you buy as some of them eat the coils.

rscole86

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#3372740 13-May-2025 11:42

Have you seen the recent thread?

johno1234

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#3372746 13-May-2025 12:08

Some heat pumps have a self cleaning function for both indoor and outdoor unit. They freeze and thaw the moisture on the fins to push the dirt out using the freezing water's expansion.

gzt

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#3372750 13-May-2025 12:30

rscole86:
Have you seen the recent thread?

July 2024, nearly a year ago. I missed that one.

Gordy7

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#3372761 13-May-2025 12:57

I recently washed the fins on my outdoor split heat pump unit. Over the last 10 years I had only used compressed air annually on the fins.

Prior to the last 10 years it seems that no maintenance was ever done on the heat pump judging by the wads of dust blocking the indoor unit filters.

My Fujutsu 8.5kW heat pump would shut down on cold mornings giving an LED error: Discharge Temperature Abnormal.

A search on Google suggested either the outdoor unit fins needed cleaning or gas needed topping up.

I made a solution of 2 caps of car wash cleaner (I read dish detergent is too strong or corrosive) in a 1/3 of a bucket of water.

Sprayed the fins with the solution using a garden pressure sprayer and later sprayed with cold water using a garden hose with a spray nossle.

Heaps of gung came out. The heat pump has not faulted since. Remember to turn off the power to the heat pump system during cleaning.

Gordy

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tweake

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#3372771 13-May-2025 13:30

Gordy7:

I made a solution of 2 caps of car wash cleaner (I read dish detergent is too strong or corrosive) in a 1/3 of a bucket of water.

Sprayed the fins with the solution using a garden pressure sprayer and later sprayed with cold water using a garden hose with a spray nossle.

the trouble with car wash is if its has wax etc in it. thats best avoided.

dish detergent is fine, its safe on your hands. some of the dishwasher or laundry soap is quite alkaline and that could corrode if left on. they might have meant, dishwasher not dish. some of the commercial hvac cleaner is an aluminum brightener which eats the top layer off. thats best left to commercial guys.

also if you rinse it off, its all fine.

Gordy7

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#3372778 13-May-2025 14:07

tweake:

Gordy7:

I made a solution of 2 caps of car wash cleaner (I read dish detergent is too strong or corrosive) in a 1/3 of a bucket of water.

Sprayed the fins with the solution using a garden pressure sprayer and later sprayed with cold water using a garden hose with a spray nossle.

the trouble with car wash is if its has wax etc in it. thats best avoided.

dish detergent is fine, its safe on your hands. some of the dishwasher or laundry soap is quite alkaline and that could corrode if left on. they might have meant, dishwasher not dish. some of the commercial hvac cleaner is an aluminum brightener which eats the top layer off. thats best left to commercial guys.

also if you rinse it off, its all fine.

Thanks for that advice.

It is now obvious to me now that the compressed air did not do a good enough job cleaning the fins.

Any wax residue in the cleaning method I used is not as bad as all the gunge that came out that was blocking the fins.

Gordy

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gzt

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#3372793 13-May-2025 15:05

My Hitachi the outdoor component model RAC-S50YHA is large and standing on a concrete pad.

The fan is on the outer face. It looks like there are multiple screws holding the covers on. I'm thinking I'll take off the front and top cover initially and see what kind of access that gives me.

Looking at the rear there is 100mm between the unit and the wall. Not a lot of working area. I hope no serious rear access is required. I see a bit of rust on the mild steel grid cover at the back.

.

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#3372823 13-May-2025 16:06

gzt: My Hitachi the outdoor component model RAC-S50YHA is large and standing on a concrete pad.

The fan is on the outer face. It looks like there are multiple screws holding the covers on. I'm thinking I'll take off the front and top cover initially and see what kind of access that gives me.

Looking at the rear there is 100mm between the unit and the wall. Not a lot of working area. I hope no serious rear access is required. I see a bit of rust on the mild steel grid cover at the back.

.

i hate it when they install them at the minimums. heat pumps need airflow, lots and lots of airflow.

for a big clean, i just pop the top off and then you get good access to the coil and check if anything has built up at the bottom etc.

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#3373770 16-May-2025 16:52

Gordy7:

I recently washed the fins on my outdoor split heat pump unit. Over the last 10 years I had only used compressed air annually on the fins.

Prior to the last 10 years it seems that no maintenance was ever done on the heat pump judging by the wads of dust blocking the indoor unit filters.

My Fujutsu 8.5kW heat pump would shut down on cold mornings giving an LED error: Discharge Temperature Abnormal.

A search on Google suggested either the outdoor unit fins needed cleaning or gas needed topping up.

I made a solution of 2 caps of car wash cleaner (I read dish detergent is too strong or corrosive) in a 1/3 of a bucket of water.

Sprayed the fins with the solution using a garden pressure sprayer and later sprayed with cold water using a garden hose with a spray nossle.

Heaps of gung came out. The heat pump has not faulted since. Remember to turn off the power to the heat pump system during cleaning.

This is pretty much what a "professional" did to clean ours.

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linw

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#3374055 17-May-2025 15:11

Two comments.

It is not old - they will last at least 15+ years.

Make sure that the floor isn't getting rusty. That killed my 15-16 year old one as the motor/fan lost its anchor point!

TwoSeven

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#3374176 17-May-2025 16:58

I've always had mine serviced. I did once watch a video on how to do it, but it turns out while it seemed relatively straight forward, there were a bunch of things one has to be aware of. Can't remember what they were though, it was a while ago.

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#3374182 17-May-2025 17:41

I use car wash cleaner, I'm told (have no idea how true...can't be bothered to look it up) that Dishwash has salt in it so that's why you don't use it on cars ... feel free to flame me...

Matthew

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#3374230 18-May-2025 03:28

mdooher:

I use car wash cleaner, I'm told (have no idea how true...can't be bothered to look it up) that Dishwash has salt in it so that's why you don't use it on cars ... feel free to flame me...

car wash can have wax in it.