When colder weather arrives, one of the most frustrating things is turning on the heating and realizing it doesn’t warm up the home properly: it takes too long, only heats certain rooms, never reaches the desired temperature, or the air feels barely warm.
In Torrevieja, where many homes use heat pumps, electric radiators, split air conditioning systems or aerothermal solutions, this issue can have several different causes.
In this article, we explain the most common problems, how to identify them, and when it’s best to call a professional to avoid bigger breakdowns.
1) The Thermostat Is Incorrectly Set (or Not Working Properly)
It sounds simple, but it’s one of the most common reasons.
Typical signs
- The heating turns on and off randomly
- The temperature shown doesn’t match the real room temperature
- It never reaches the set temperature
How to check it
- Make sure it’s set to HEAT mode (not cooling or fan mode)
- Check that the temperature setting is higher than the current room temperature
- If it runs on batteries, replace them
- If the thermostat is placed near sunlight or drafts, it may measure incorrectly
📌 Tip: if you use a smart thermostat, check schedules, eco mode or lock settings.
2) Lack of Maintenance: Dirty Filters or Blocked Airflow
In systems like split air conditioners with heat pump mode, dirty filters reduce airflow and make the unit work harder with poorer results.
In radiator systems, circulation issues may appear too.
Typical signs
- It warms very little even though the system is “running”
- Less airflow coming out of the indoor unit
- Higher energy bills with no comfort improvement
How to check it
- If you have a split unit: open the cover and inspect the filters (if dusty or dark, they need cleaning)
- If you have radiators: check whether some radiators are hot at the bottom but cold at the top
📌 In areas like Torrevieja, with humidity and seasonal use, maintenance is essential to keep performance high.
3) Air Trapped in the System (Water Radiators)
If your home uses water-based radiators, trapped air can prevent heat from circulating properly.
Typical signs
- Radiators only warm up partially
- Bubbling noises
- Temperature differences between rooms
How to check it
- Touch the radiator: if it’s warm at the bottom and cold at the top, there’s likely air inside
✅ Common solution: bleeding the radiators (carefully and following instructions).
4) Low Boiler Pressure (If You Have a Boiler)
If your heating system runs on a boiler, incorrect pressure can stop water from circulating properly.
Typical signs
- Heating works poorly or shuts down
- Error codes on the boiler
- Radiators feel lukewarm
How to check it
- Look at the pressure gauge: usually 1–1.5 bar is normal (it may vary depending on the system)
📌 If pressure drops repeatedly, there may be a leak or expansion vessel issue.
5) The Heat Pump Is Running, But Performance Is Low Due to Conditions or Settings
Torrevieja winters are mild, but on cold and humid days heat pumps may:
- Take longer to warm up
- Trigger defrost cycles
- Heat inconsistently
Typical signs
- Warm (not hot) air in heating mode
- The system can’t reach the target temperature
- It stops and restarts frequently
How to check it
- Make sure it’s in HEAT mode
- Set the temperature around 21–23ºC (no need to set it to 30ºC)
- Aim the louvers downward (warm air rises, so this helps distribute heat better)
📌 Setting the temperature too high doesn’t heat faster—it only increases energy use and strain.
6) The System Is Undersized for the Space
If your heating “works” but never warms the room properly, the system may not have enough power.
Typical signs
- Large rooms never feel warm
- The system runs constantly at maximum
- Small rooms heat up fine
How to check it
- A split unit in a large open-plan living room may be too small
- High ceilings and poor orientation can reduce performance
📌 In coastal homes, insulation and window quality also play a big role.
7) Heat Loss: The Problem Might Be the Home, Not the Heating
Sometimes the system works correctly, but the home loses heat too quickly.
Typical signs
- The house cools down quickly after switching off
- Drafts near windows
- Big temperature differences between rooms
How to check it
- Inspect window seals
- Look for uninsulated shutter boxes
- Cold walls or humidity can make the space feel colder
✅ Simple solutions:
- Add weatherstripping
- Use thermal curtains
- Keep doors closed to concentrate heat in used areas
8) The Outdoor Unit Is Dirty or Poorly Ventilated (Heat Pumps)
In split systems and aerothermal heating, the outdoor unit is essential for generating heat.
Typical signs
- Reduced heating power
- Higher energy consumption
- Unusual noises
- Frequent shutdowns
How to check it
- Make sure it isn’t blocked by leaves, dust or objects
- Ensure it has enough open space for ventilation
📌 Near the sea, dirt and salt can accelerate wear if the unit isn’t checked regularly.
9) Low Refrigerant (Heat Pump Systems)
If your heating comes from an air conditioner in heat mode, low refrigerant can greatly reduce heating capacity.
Typical signs
- Lukewarm or cool air in heating mode
- Takes a long time to warm up
- Ice on pipes or the outdoor unit
- High energy use
How to check it
It’s difficult to confirm without tools, but if symptoms persist, a professional inspection is recommended.
📌 Important: refrigerant doesn’t “run out”. If it’s low, there’s usually a leak or system fault.
10) Internal Component Failure: Fan, Control Board, Sensors…
If the issue isn’t settings or maintenance, there may be a technical fault.
Typical signs
- The system turns off by itself
- Error codes appear
- Strange noises
- It doesn’t respond properly to the remote or thermostat
How to check it
- Write down any error code
- Confirm the remote is working
- If the system keeps restarting, don’t force it—this can worsen the problem
When Should You Call a Technician?
It’s best to call a professional if:
- Heating is weak even with correct settings
- Some radiators stay cold even after bleeding
- Boiler pressure keeps dropping
- You hear unusual noises
- Error codes appear
- You smell burning or the circuit breaker trips
- Your energy bill increases suddenly without reason
Catching the problem early can prevent bigger repairs.
Tips to Improve Heating Performance and Reduce Energy Use
Here are simple recommendations that work:
✅ Keep a stable temperature (21–23ºC)
✅ Clean filters regularly (heat pump systems)
✅ Avoid constant window opening
✅ Use HEAT mode and direct airflow downward
✅ Don’t block radiators or air vents
✅ Schedule annual maintenance before winter
Conclusion
If your heating isn’t warming properly, the most common causes are incorrect settings, lack of maintenance, trapped air in the system, or heat loss in the home. Identifying the cause early is key to restoring comfort and avoiding unnecessary costs.
If you’re in the area and need a check-up, AC Torrevieja can help you diagnose the issue and improve your heating system’s performance.