Balboa Clim8zone II Mini Heat Pump Review: Specs, Compatibility and Alternatives

Last updated: September 2026

Is the Balboa Clim8zone II Mini the air source heat pump for you? I’ll admit I was fairly scathing about the first Clim8zone, and I’m still not a fan of it. The Clim8zone II is Balboa’s second go at a heat pump that plugs straight into their spa packs. Is it any good? Let’s dive in.

To be clear, I haven’t had one on test. This review is based on Balboa’s documentation and specifications, checked against the current user manual and spec sheets. But I’ve supplied enough air source heat pumps to customers that I know what to look for in the specs.

What is the Balboa Clim8zone II Mini?

As the name suggests, it’s a mini heat pump. Mini heat pumps are nothing new. They’ve been around for a long time (I’ve reviewed the Onda Mini, for example). But Balboa is one of the top two makers of hot tub equipment, so they’ll lean on their name and push compatibility with the spa packs and topsides that people already have in their tubs.

The Clim8zone II is a 4kW heat pump that integrates with certain BP systems. It plugs into the pack’s 230V accessory output, and you run it from the topside. It works down to -5°C, which is pretty good for a small heat pump, and it’s quiet. It’s about half the size of the first Clim8zone, according to Balboa’s launch release. One of the first manufacturers to use it was Master Spas, in its cold tubs, which tells you where Balboa sees it: small tubs and cold plunges.

What are the stand-out points?

• Heats and cools
• 4kW heating (at 27°C air)
• Smart variable-speed compressor
• Integrated with selected BP systems
• Works down to -5°C (23°F)
• Quiet: 45dB(A) or less at 1m
• Compact: about 500 x 500 x 490mm (19.6in x 19.5in x 19.1in)

Specifications

These figures come from the Clim8zone II 230V user and service manual and Balboa’s Clim8zone II page:

Spec	Clim8zone II (230V)
Part numbers	73013 (230V, previously 73005); 73011 is the US 115–120V version
Heating at 27°C air / 27°C water	1.0–4.0kW, COP 9.5–5.0
Heating at 15°C air / 26°C water	0.65–2.5kW, COP 6.1–4.0
Cooling	1.6kW
Air temperature range	Heating -5°C to 43°C; cooling 10°C to 40°C
Noise	45dB(A) or less at 1m
Power	220–240V, 5.5A max, 30mA RCD protection
Water connections	1.5in (48.3mm) on the 230V model; 2in on the US model
Advised water flow	1.72m³/h (about 29 litres a minute)
Refrigerant	R32
Size	496 x 498 x 486mm
Weight	About 28kg net (manual)

What is it compatible with?

This is always my bugbear with Balboa’s marketing. In my opinion it’s misleading about compatibility. You wouldn’t believe how many emails I’ve had about the original model.

The sales sheet at launch said it was compatible with all BP systems. It isn’t, and Balboa’s own page now says “most BP series control systems”. I have a BP601, and because it’s the older version, it isn’t compatible. The pack has to be one of the “C8Z” versions:

Compatible spa packs	Compatible topsides
BP6013G1 – C8Z	spaTouch3 (v3.2 or later)
BP6013G2 – C8Z	spaTouch2 (v2.36 or later)
BP6013G3 – C8Z	spaTouch Mini
BP2100G0 – C8Z	TP700
BP2100G1 – C8Z	TP740
BP214PBC – C8Z

Pack list from the Clim8zone II sales sheet. Panel versions are from Balboa’s BP6013G1 tech sheet, which also says Clim8zone isn’t compatible with 2x16A wiring.

The hugely popular TP600, which is fitted to a gazillion hot tubs, isn’t on the list. So if your topside or pack isn’t listed, you could be looking at an expensive upgrade before the heat pump will even talk to your tub. Please check the model and serial numbers on your equipment before you buy. My guides to identifying a Balboa circuit board and choosing a Balboa topside will help. If you’re upgrading anyway, see my TP700 review and spaTouch Mini review.

What are my final thoughts?

I’m always a fan of bigger heat pumps than this. If you’ve read my blog or watched my YouTube channel, you’ll know I put a 21kW on my own tub. It’s a big tub at around 2,700 litres, but still, that’s a long way from a 4kW unit. And I still love it.

Look at what you’ll actually get out of it. At 27°C air (how often do you get that in the UK?) you get 4kW of heat. At 15°C you get 2.5kW, which is less than the 3kW electric heater most of you already have in your tub. In winter, yes, it’ll work down to -5°C as Balboa says, but the manual only gives output figures at 27°C and 15°C, so expect less again. It’s going to cost you a lot less to run in spring and summer, but the heat output is low, and heat-up will be slower than the element it replaces.

Then there’s compatibility. A huge part of the retrofit market can’t use it. For new tubs, and for plastic shell manufacturers building it in at the factory, I can see this working well for Balboa, especially on cold plunges, where the cooling is a real bonus. But most of my heat pump customers are retrofitting, and it isn’t going to suit most of them.

How much does it cost?

Ignoring any upgrades you might need to your topside or spa pack (ouch!), the Clim8zone II Mini is listed at around £870–£925 inc VAT in the UK. Hydrospares lists it at £866.66 against an RRP of £924.18. In the USA, the 115V version (73011) has an RRP of $1,999.99. For a 4kW unit, that’s expensive in my humble opinion.

What’s the alternative?

For me, it’s a no-brainer: a bigger standalone heat pump, controlled by flow. That’s how I guide all my retrofit customers to install their heat pumps. It won’t connect directly to a select few BP packs and topsides, but it doesn’t need to. See How to control a heat pump with any hot tub spa pack.

	Balboa Clim8zone II Mini	Comfortline 7kW with WiFi
Output at 15°C air	2.5kW	5.0kW
COP at 15°C, full output	4.0	6.0
Type	Variable speed	Full inverter
Works with	Listed C8Z BP packs and topsides	Any spa pack, by flow
UK price	About £870–£925	£897

My go-to small alternative was the Vian Power C5, a 5kW on/off heat pump. It’s out of stock as I write this, so the in-stock option is the Comfortline 7kW with WiFi. It gives double the heat at 15°C, runs more efficiently and has a similar footprint, for about the same money. For me, that’s a no-brainer. More on the Vian range in my Vian Power heat pump review, and on the Comfortline in my Comfortline review.

You can see the full range, and the connection kits, in my store. Before you buy, read 5 things to consider before fitting a heat pump, my ultimate guide to air source heat pumps for hot tubs and How to choose the right air source heat pump.

Building a tub or cold plunge from scratch? My DIY hot tub plans give you the full plumbing layout and parts list, so the heating is planned in from day one.

FAQs

Is the Balboa Clim8zone II the same as the Clim8zone II Mini?

Yes. Balboa calls it the Clim8zone II, and most retailers call it the Mini. It’s the 4kW unit. The larger 6kW original is now called the Clim8zone I.

How powerful is the Clim8zone II Mini?

4kW at 27°C air and 2.5kW at 15°C air, according to the manual. In cooler weather it gives less heat than a standard 3kW spa heater, but uses far less electricity.

Is the Clim8zone II compatible with a TP600?

No. The TP600 isn’t on the list. You need a spaTouch2, spaTouch3, spaTouch Mini, TP700 or TP740, plus one of the C8Z versions of the BP6013, BP2100 or BP214 packs.

Can the Clim8zone II cool a cold plunge?

Yes, it heats and cools (1.6kW cooling), and Balboa aimed it at cold tubs. For serious ice bath temperatures, check the cooling limit on the version you’re buying.

Is there a better alternative for an existing hot tub?

For most retrofits, a standalone inverter heat pump of 7kW or more, controlled by flow, gives around twice the heat for similar money and works with any spa pack.

Hope you’ve found this useful. If you’ve got a question, drop it in the comments below. I read them all.

Cheers,
Andi

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Hi, Andi here. I own Buildahottub.com and also write all of the articles and info pages on the site. Some years back now, I built my own hot tub but struggled to find the information I needed. So, once my tub was complete, I started this website to help others in their own pursuit of hot tub and plunge pools DIY building information.

Fast forward to 2025, I've helped over 1400+ DIY customers just like you all over the world build hot tubs and pools. Have a good look around the site, there are lots of resources here. Please do get in touch if I can help you. - Cheers, Andi