Cleaning Heat Pump Outside Unit?

Forums › Home Workshop DIY › Cleaning Heat Pump Outside Unit?

evilengineer

466 posts

Ultimate Geek
+1 received by user: 367

#315390 11-Jul-2024 09:29

Has anyone tried cleaning the radiator fins on a heat pump outside unit?

Our living room heat pump, now quite old (wasn't new when we bought the house 9.5yrs ago), isn't kicking out much heat these days even when set at 28deg.

A check of the outside unit shows the fins behind the fan to be pretty gungy which is no doubt affecting performance.

Has anyone tried cleaning the fins on their unit?

A quick look on You Tube shows people squirting the fins with a hose pipe (not with a water blaster, though) through to using some sort of expanding foam cleaning product.

Would be interested in any tips and whether it made any difference to performance.

It may just be time to stump up and buy a new heat pump.

1 | 2

4718 posts

Uber Geek
+1 received by user: 681

Trusted

#3258360 11-Jul-2024 09:36

I used pressure washer to clean the outside compressor unit and just made sure the PSI was lowest I could set it to and I also used a 40 degree nozzle on the pressure washer lance. No damage to the fins, looks good as new after 3 years of use.

Do whatever you want to do man.

timmmay

20923 posts

Uber Geek
+1 received by user: 5395

Trusted

Lifetime subscriber

#3258362 11-Jul-2024 09:46

I just use a hose, that's what the professional did when I watched them. That metal is fairly soft, I would be careful with pressure washers.

Given the state of it perhaps you should invest the $100 or so in a professional clean, see if it improves, if not it's either get it fixed or at that age more likely replace it. If you get a professional in, tell them in advance that the fins are quite clogged so they know to bring anything extra they might need.

peejayw

1918 posts

Uber Geek
+1 received by user: 123

#3258365 11-Jul-2024 09:47

Also interested in this.

I'm supposed to respect my elders, but it's getting harder and harder for me to find one now.

alisam

916 posts

Ultimate Geek
+1 received by user: 89

#3258367 11-Jul-2024 09:53

My first (and only) Service for my single heat pump was $159.00 in June 2023. I am in Auckland.

PC: Dell Inspiron 16 5640 (Windows 11 Home), Dell Inspiron 7591 2n1 (Windows 11 Pro), HP ProBook 470G1 (Windows 10 Pro), Intel NUC7I5BNH (Zorin)
Net: Grandstream 1 x GWN7062 Router, 1 x GWN7665 Access Point
Storage: Synology DS216play NAS, 2 x 6TB
Media: 3 x Amazon FireTV. Echo, Dot, Spot
TV: 2 x Samsung H6400 55" LED TV, Panasonic TH-P50G10Z 50" Plasma TV
Mobile: Samsung Galaxy A52 5G
Wearable: Gear S3 Frontier

tweake

2716 posts

Uber Geek
+1 received by user: 1168

#3258378 11-Jul-2024 10:26

i don't recommend pressure washers and its not needed.

normal hose is often all thats needed. give the coil a soak first. a mild detergent, like dishwashing soap, will help a bit. then a decent hose out. if its really dirty you might have to get some proper foaming detergent. but i would recommend staying away from any commercial brightener type cleaners. they are typically acid and work by removing a layer of metal.

if the coil is greasy, usually because there is a range hood outlet nearby, then ask a pro as you need the right cleaners to get the oil off without causing damage.

evilengineer

466 posts

Ultimate Geek
+1 received by user: 367

#3258380 11-Jul-2024 10:41

timmmay: I just use a hose, that's what the professional did when I watched them. That metal is fairly soft, I would be careful with pressure washers.

Given the state of it perhaps you should invest the $100 or so in a professional clean, see if it improves, if not it's either get it fixed or at that age more likely replace it. If you get a professional in, tell them in advance that the fins are quite clogged so they know to bring anything extra they might need.

I'm quite tempted to just give it a go in a "last chance saloon" type way.

Given its age, not a biggie if it doesn't make much difference as it really is at end of life.

It would be a chance to get a more modern heat pump with better cold weather performance.

But would also be nice not to have to spend the money. 😀

Dyson

Shop now for Dyson appliances (affiliate link).

tweake

2716 posts

Uber Geek
+1 received by user: 1168

#3258382 11-Jul-2024 10:54

evilengineer:

I'm quite tempted to just give it a go in a "last chance saloon" type way.

Given its age, not a biggie if it doesn't make much difference as it really is at end of life.

It would be a chance to get a more modern heat pump with better cold weather performance.

But would also be nice not to have to spend the money. 😀

no ice on the outside coil ?

what part of the country are you in? and what was the outside temps when you where running it?

rscole86

5002 posts

Uber Geek
+1 received by user: 467

Moderator

Trusted

Lifetime subscriber

#3258384 11-Jul-2024 11:06

Just watching the neighbours get cleaned as we speak, only using the garden hose, mostly using the shower setting rather than jet/full.

Though I seem to recall them getting it cleaned yearly as it's a large outdoor/ducted set up.

evilengineer

466 posts

Ultimate Geek
+1 received by user: 367

#3258402 11-Jul-2024 12:00

tweake:

no ice on the outside coil ?

what part of the country are you in? and what was the outside temps when you where running it?

No ice.

We're only in the Waikato but it can easily get down to -2 or -3 on frosty mornings.

Current Panasonic was never that good when it gets this cold and seemed to spend a lot of time blowing cold air while running its cold weather cycle outside.

If I go with a replacement it will be a Mitsubishi or something rated for low temperature performance. Particularly as I'm too tight to let the family use it for cooling in the summer. 😀

tweake

2716 posts

Uber Geek
+1 received by user: 1168

#3258421 11-Jul-2024 12:30

evilengineer:

tweake:

no ice on the outside coil ?

what part of the country are you in? and what was the outside temps when you where running it?

No ice.

We're only in the Waikato but it can easily get down to -2 or -3 on frosty mornings.

Current Panasonic was never that good when it gets this cold and seemed to spend a lot of time blowing cold air while running its cold weather cycle outside.

If I go with a replacement it will be a Mitsubishi or something rated for low temperature performance. Particularly as I'm too tight to let the family use it for cooling in the summer. 😀

give it a clean it first.

if you can find the model numbers. also what size room and what sort of insulation that the room has. that way i can get a rough idea on sizing.

a new heat pump won't change the defrost cycle in those conditions. thats just the downside of those outdoor temps and humidity, its icing up. if it wasn't completely white with ice, then it has issues probably due to being dirty. but even a new one will still go into defrost at those temps. trouble is you not in a cold enough area to reduce the outdoor humidity, but still cold enough for icing to occur.

a low temp performance heat pump is waste of money imho in those temps. they are basically a bigger coil. really meant for places that snow a fair bit. waikato is warm enough that they are not needed.

openmedia

3498 posts

Uber Geek
+1 received by user: 903

Trusted

#3258443 11-Jul-2024 13:37

Have you checked and cleaned the filters on the indoor unit?

Generally known online as OpenMedia, now working for Red Hat APAC as a Technology Evangelist and Portfolio Architect. Still playing with MythTV and digital media on the side.

Lego

Shop now for Lego sets and other gifts (affiliate link).

evilengineer

466 posts

Ultimate Geek
+1 received by user: 367

#3258446 11-Jul-2024 13:43

That's already on the to do list for the weekend as well.

Obraik

2167 posts

Uber Geek
+1 received by user: 1347

#3258451 11-Jul-2024 14:02

If cleaning it doesn't help then it's also possible that it could have a refrigerant leak

Looking to buy a Tesla? Use my referral link and we both get credits

evilengineer

466 posts

Ultimate Geek
+1 received by user: 367

#3258454 11-Jul-2024 14:08

tweake:

give it a clean it first.

if you can find the model numbers. also what size room and what sort of insulation that the room has. that way i can get a rough idea on sizing.

a new heat pump won't change the defrost cycle in those conditions. thats just the downside of those outdoor temps and humidity, its icing up. if it wasn't completely white with ice, then it has issues probably due to being dirty. but even a new one will still go into defrost at those temps. trouble is you not in a cold enough area to reduce the outdoor humidity, but still cold enough for icing to occur.

a low temp performance heat pump is waste of money imho in those temps. they are basically a bigger coil. really meant for places that snow a fair bit. waikato is warm enough that they are not needed.

We've got two heat pumps that came with the house, a Panasonic in the living room and a smaller Fujitsu in the kitchen. Model numbers unknown but both likely over 15yrs old.

And to be honest, the Fujitsu has always seemed to be the better performer out of the two on a cold morning. Maybe that's just me.

The living room is quite large, though. Approx 8m long by 4m wide with the high level unit roughly half way along one of the long walls.

The roof space and underfloor are well insulated (done by myself) but the walls are uncertain given the 1970s construction. Windows double glazed also, but one of the 4m walls is pretty much all window/ranch slider.

Given the somewhat novel configuration of the house, the master bedroom (roughly 12-15m2) is directly adjacent to the main living area and if we end up getting a new heat pump I'll be tempted to consider a small multi-room set up with two wall units running off the same outdoor box.

tweake

2716 posts

Uber Geek
+1 received by user: 1168

#3258475 11-Jul-2024 15:09

evilengineer:

We've got two heat pumps that came with the house, a Panasonic in the living room and a smaller Fujitsu in the kitchen. Model numbers unknown but both likely over 15yrs old.

And to be honest, the Fujitsu has always seemed to be the better performer out of the two on a cold morning. Maybe that's just me.

The living room is quite large, though. Approx 8m long by 4m wide with the high level unit roughly half way along one of the long walls.

The roof space and underfloor are well insulated (done by myself) but the walls are uncertain given the 1970s construction. Windows double glazed also, but one of the 4m walls is pretty much all window/ranch slider.

Given the somewhat novel configuration of the house, the master bedroom (roughly 12-15m2) is directly adjacent to the main living area and if we end up getting a new heat pump I'll be tempted to consider a small multi-room set up with two wall units running off the same outdoor box.

i find the small bedroom ones do heat up quicker, but as its hard to get small enough heat pumps, they are well oversized for the rooms. good for quick heat up but they also overshoot.

one thing to consider is those cool nights (probably the next few nights as well) will be down around or below design temp. ie the heat pump may be to small to maintain the temp you want. that gets worse if your trying to heat a cold room up. now that is by design and is actually good. its good because it means it will operate more efficiently in the warmer temps you get more often. we don't size heat pumps for the coldest day, as that's expensive and increases running costs just to save you wearing some extra clothes a few times a year.

once you get it all cleaned up, i would start it after lunch (or run it all day) and then see what happens as the outdoor temps cool down.

1 | 2