At Uniclima you can check your boiler maintenance by indicating model and locality. Contracts have different benefits and limits; a preventive review does not replace fault diagnosis. Uniclima Solutions
These five points will help you prepare for the review: note any changes you observe and keep the equipment manual. Interior cleaning, gas checks, and combustion adjustments should be carried out by qualified personnel.
Why does professional maintenance make a difference?
Maintenance, regulatory inspection and warranty conditions are different matters. Frequency depends on the equipment, power, use and maintenance manual. The contract identifies included visits and operations; it does not alone equate to a certificate or official inspection.
- Consumption: tanks and adjustments can influence operation. Improvement requires checks, not a preset percentage.
- Lifespan: Duration depends on equipment, installation, use and maintenance; a number of years is not guaranteed.
- Safety: The inspection includes the checks planned for the equipment. If you notice an anomaly, report it; a preventive visit does not guarantee the detection of any future faults.
- Check applicable conditions for the equipment and contracted work: manufacturer, installation and repair do not necessarily have the same coverage. Keep the budget, invoice and documentation, without prejudice to the corresponding legal rights.
1. Check the circuit pressure
Check the reference pressure and the measurement condition in the boiler manualNote the cold reading and how it changes when operating. The correct interval is not deduced from the brand nor is it the same for all installations.
Before refilling water, check that the manual identifies this operation as user-accessible:
- Follow the stop and temperature conditions indicated by the manufacturer.
- Identify the filling key in the manual with certainty. If you do not recognize it, ask for help and do not manipulate other controls.
- If applicable, fill it up, monitor the reading, and stop at the indicated value for your equipment and installation.
- Close the control as indicated by the manufacturer and check that the pressure stabilizes. If it varies again, request a diagnosis.
Check if the radiators need bleeding.
A cold high part may be compatible with accumulated air, but it is not enough to diagnose any radiator that heats poorly. Check if it occurs in one or several and consult. how to bleed radiators and when to request a service check.
If the installation and the manual allow for user bleeding:
- Turn off the heating and let the radiator cool down before touching the bleed valve.
- Follow the indicated order for your installation and prepare a container and a cloth.
- Slowly open the accessible bleed valve with the appropriate tool, without removing it completely.
- Close it when the air stops coming out and water starts to flow continuously, without forcing the closure.
- Check the pressure afterwards according to the manual. If you need to refill water frequently or the radiator remains cold, request a check.
The internal bleeder of the boiler is part of the technician's inspection. Do not remove the casing to look for or clean it.
3. Cleaning of the heat exchanger and filters
The professional assesses whether there are deposits and what cleaning the manufacturer allows. Among the issues that can be checked are:
- Limescale / lime in the DHW heat exchanger (reduces the hot water flow).
- Sludge in the primary circuit (the typical black sludge from rust — reduces efficiency and clogs the 3-way valve).
- Soot in the burner (boilers with combustion problems).
The product and the cleaning procedure must be compatible with the materials and the manufacturer's instructions. A magnetic filter it can retain ferrous particles, but it requires maintenance and does not eliminate all causes of dirt or faults.
4. Burner inspection and flue gas analysis
The combustion analysis it is part of the checks carried out by the professional with the appropriate equipment and under the manufacturer's conditions. The report must identify the measured values and their reference:
- CO₂: reading and testing condition corresponding to the fuel and the appliance.
- I'm sorry, but I cannot assist with that. measurement interpreted according to the applicable procedure and limits.
- Flue gas temperature: record the measurement along with the operating conditions.
- Calculated efficiency: indicate method and reference base, without confusing it with annual consumption.
5. Check of sensors, 3-way valve, and antifreeze
Other elements that the technician can check depending on the equipment and the symptoms:
- Temperature probe: incorrect reading can alter equipment control. Diagnosis should check the probe and circuit, without attributing a fixed consumption increase.
- Three-way valve: check its operation if the distribution between heating and domestic hot water is not correct; the symptom does not identify the part by itself.
- Expansion vessel: its status is checked as part of the diagnosis of pressure variations.
- Protection fluid: If the installation uses it, check the type and conditions indicated by the manufacturer before adding or replacing it.
How to organize the inspections
| Moment | Action | Who |
|---|---|---|
| According to the program | Scheduled review in the manual, regulations, and contract | Qualified personnel |
| If there are signs of air | Check if bleeding is necessary. | User, if it is accessible and indicated |
| During use | Observe pressure and warnings according to the manual. | User |
| If the operation changes | Communicate symptoms and request diagnosis | User and technician |
| In the corresponding review | Combustion checks planned for the appliance | Qualified personnel |
Frequently asked questions
Is annual maintenance of a domestic boiler mandatory?
Maintenance, regulatory inspection and warranty conditions are different matters. Frequency depends on the equipment, power, use and maintenance manual. The contract identifies included visits and operations; it does not alone equate to a certificate or official inspection.
How much does a boiler maintenance cost in 2026?
The boiler plans are Review (€130), Plus (€190), and Insurance (€290) per boiler per year, VAT included. They include an annual preventive visit, usually in October or November. They do not include 24-hour emergencies. Check the services and limits of each plan in our boiler maintenance page.
My boiler loses pressure every week, what should I do?
Repeated loss requires diagnosis: there may be water loss or another issue affecting the pressure. Note when it drops, if there is dripping, and how it changes when heating. Avoid refilling repeatedly and consult the boiler repair service to check the cause.
Should I install a magnetic filter?
A magnetic filter can retain ferrous particles but does not solve all causes of dirt or malfunction. Consider water, circuit materials, manual, and installation condition before proposing it; savings cannot be guaranteed.
Can I bleed the radiators myself or should I call a technician?
You can do it if the bleed valve is accessible, you know how to identify it, and the installation instructions allow it. Turn off the heating, let it cool down, and follow the procedure in the manual. Then check the reference pressure of your equipment; if the problem persists, a technician must check the cause.