Onda Mini Air Source Heat Pump Review

Onda Mini

I talk a lot about air source heat pumps on this blog and my YouTube Channel; in this post, we are going to review the Onda Mini Air Source Heat Pump. The Onda Mini Air Source Heat Pump is a way to save money on your hot tub running costs without the expensive initial outlay of cash.

Let’s see in a sub £800 investment can actually save you money on your Hot Tubs.

What is the Onda Mini Air Source Heat Pump?

The Onda Mini Air Source Heat Pump  is a range of plug and play 3.5KW, 5KW and 7KW Air Source Heat Pumps.

The Onda comes with a regular plug so you can simply connect it to the mains making the electrical installation none existent.

Unsuspectingly, this unit is actually made in Europe so comes with European quality of craftsmanship with “made in China” prices – this is a win win so far.

With a maximum output of 7KW on the largest model, we are not going to be heating our swimming pools with this range of heat pumps, but they are perfect for hot tubs.

What is the difference between a Mini Heat Pump and a Regular one?

The main differences between a Mini Heat Pump and a regular one, are the heating capacity, the COP which stands for coefficient of performance and the electrical hook up.

The heating capacity of these mini heat pumps is a lot less than the regular ones. For example, the Onda Mini Air Source Heat Pump range only goes up to 7KW which is the entry point for many of the larger “regular” heat pumps on the market.

The average COP of the Onda Mini Air Source Heat Pump is around 4-4.5 which is lower than the Comfortline for example which is around 6 on average.

In terms of installation, the Onda Mini Air Source Heat Pump is just a regular plug that you plug into a socket or outlet. Normally for an ASHP you would have to hard wire these into your electricity supply just as you would with your Hot Tubs.

Can I use an Onda Air Source Heat Pump all year round?

For the climate that we have in the UK and Europe, this is not an all year Heat Pump. When the mercury drops below around 8C / 47F the unit is going to struggle to heat at any meaningful COP and you are going to need to give your tub a boost with the electrical heater.

That said, if you are not planning to use your heat pump during the winter months, or don’t mind switching back to electric during a cold snap, then this range can still save you considerable amount of money.

If you are paying for 1KW of electricity but are able in the best conditions to get 4.5KW of heat out of it – that is quite the saving.

What are the positives for the Onda Mini Air Source Heat Pump?

Firstly, the price. This is a really competitively priced unit to enter you into Air Source heating for your hot tub.

I love the fact that this just plugs into a regular socket. There is not need for an electrician or a worry about wiring it yourself. It comes with a regular plug.

The small footprint means that it is less intrusive in a smaller back year.

I also like the fact that you can easily store it away for the winter.

What about the negatives?

The main negative for the Onda Mini Air Source Heat Pump has to be the fact that it is not an all season air source. The colder months will be a challenge with this range for sure.

The COP is not as high as on a regular Air Source Heat Pump. That said, it is a lot cheaper than a regular air source heat pump so there has to be a trade off somewhere.

How do I connect an Onda Mini Air Source Heat Pump  to my existing hot tub?

The first thing that you are going to need to do with your Onda Mini Air Source Heat Pump  is find a suitable location to cut into the pipework on your hot tub. Ideally, you are looking to add the Air Source just before, or just after the circulation pump.

Onda Mini Air Source Heat Pump
Onda Mini Air Source Heat Pump

Below shows the ideal location to cut the pipes on this particular hot tub.

Next, you are going to want to use one of the connection kits that I have prepared for this particular model. They come with everything you need in order to connect them to your existing tub. It is also done in a way that you can take off the heat pump for storage during the winter months for example which is pretty cool.

Just be mindful of the direction of flow. The front of the pump is always suction so in the diagram below, you can see that the direction of the water in on the blue arrow and out on the red arrow – which corresponds with the water being drawn into the front of the pump.

I would also only fit this model if you have a separate circulation pump. The Onda Mini Air Source Heat Pump and the 38mm tubing is not going to take full force from a jet pump. You might get away with opening the bypass slightly but I would not advise it – so this is on your own head if you decide to do it.

In conclusion

The Onda Mini Hot Tub and Pool Pump is ideal for the smaller swimming pool any any Hot Tub.

  • Easy to Install
  • Lower your Hot Tub running costs
  • Cheap to run
  • Small and Compact
  • Simple to use
  • European Made
  • 2 Year Warranty
  • Titanium Heat Exchanger
  • Heating water up to 40°C
  • Easy for installation Plug & Play available
  • Super energy saving: pay 1kW get 4.5kW energy in return
  • Eco-friendly Gas R32

If you are on a budget, not worries about all year round usage or using the electric heater during the cold months, then this is a great way to save money on your hot tub running costs.

If you are looking for something a little more all year round – then check out the Comfortline range of Air Source heat Pumps.

Can I help you with an Onda Mini Air Source Heat Pump?

If I can help you with any questions about an Onda Air Source Heat Pump then please do get in touch below. All models are available in my online store.

Can I Help You?

If I can help you in any way I would love to hear from you. You can get in touch using the form below.

Thanks - Andi


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.

Today, I've helped over 1000 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

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