If your boiler isn’t working, makes noises, doesn’t maintain water temperature, or increases consumption, it’s usually not “bad luck”—it’s a clear sign that your system has stopped being efficient and reliable. At AlquiConfort, we use PRO-G Holanda MIXPLUS condensing boilers because they meet what a home requires today: stability in comfort, performance, and expense control without surprises.
Below, you have a direct guide (without unnecessary technical jargon) to determine which boiler you need and which PRO-G MIXPLUS model is best for you.
1) First things first: Why a condensing boiler?
In already built homes, a condensing boiler is generally the most efficient and comfortable alternative, given that it reduces consumption compared to older technologies and recovers heat from the combustion gases. Furthermore, in the PRO-G MIXPLUS range, we are referring to a premix condensing technology designed to ensure a high seasonal performance (Class A) and ErP compliance.
Result for you: greater comfort with lower energy consumption, along with a technological foundation that is ready for the future and allows for modulating controls and outdoor probes depending on the installation.
2) The 5 questions that define which boiler you (truly) need
- How many m² is the home and what is the insulation level?
The insulation rules: a well-insulated home may require less heating power. - How many people live in the house?
The more DHW (Domestic Hot Water) usage (showers, kitchen), the higher the demand for comfort. - How many bathrooms and how many water points are used at the same time?
If there are simultaneous showers, stepping up a model is usually key. - Priority: heating, hot water, or balance?
In Spain, the “pain point” is usually DHW: when someone opens a tap and the shower goes cold. - Natural gas or LPG, and what is the flue outlet like?
It affects configuration and feasibility. The MIXPLUS allows gas type selection via parameters, but it must always be validated by an installer.
3) Which PRO-G MIXPLUS model do you need (quick map)
AlquiConfort offers 4 PRO-G Holanda MIXPLUS versions, all condensing and designed for different home profiles.
Think of it like this: the more bathrooms and the more people using hot water at the same time, the “stronger” the boiler needs to be so the shower doesn’t lose temperature.
✅ MIXPLUS 24
Who it’s for: apartments and small houses, 1 bathroom, normal use.
Typical example: 1–2 people, one shower at a time.
✅ MIXPLUS 28
Who it’s for: medium-sized homes, 1 bathroom (or 2 if not used at the same time), families.
Typical example: 3–4 people, you notice an extra boost of comfort in hot water.
✅ MIXPLUS 35
Who it’s for: medium/large homes with 2 bathrooms and higher demand.
Typical example: shower + kitchen tap at the same time, or several showers in a row.
✅ MIXPLUS 40
Who it’s for: large houses, several bathrooms or high simultaneous use.
Typical example: two people showering at the same time without the temperature dropping.
4) Rental vs Purchase: The smart decision for your case
This is where AlquiConfort changes the game compared to conventional purchasing.
If you want zero friction and zero unexpected issues: “all-in” rental
The rental model is designed for you to pay a fixed fee and not have to worry about anything else:
- Full maintenance every 24 months
- Urgent repairs included
- Replacement if it cannot be repaired
- Full warranty during the contract
If you don’t want a high initial outlay, if you care about peace of mind, or if you’re looking for a “service” model (which aligns well with European trends), it fits perfectly.
If you prefer to buy, but with coverage: All-in-Service subscription
For MIXPLUS products, options are available with an All-in-Service subscription (+€14.95/month) to maintain coverage and cost control post-installation.
Frequently Asked Questions
Is a more powerful boiler always better?
No. Oversizing can penalize performance and comfort. The key is the balance between real heating needs and DHW demand.
Which model do I choose if I have 2 bathrooms?
In many cases, MIXPLUS 35; if there is high simultaneous use or a large home, MIXPLUS 40.
How often is maintenance performed?
AlquiConfort rental includes full maintenance every 24 months, plus emergencies and replacement if applicable.