Every autumn in Tallinn and Harjumaa, the same situation repeats – on the first colder night, the heating is switched on, and it turns out that a radiator in one room stays cold, the pump makes a strange noise, or the system pressure is too low. Most of these problems are preventable if the heating system is prepared before the heating season begins, rather than waiting until the first cold spell hits.
Preparing your heating system for winter is not a difficult or necessarily expensive undertaking – most steps can be done yourself, but for some tasks, it's wise to call in a specialist. In this guide, we'll walk through the entire process, starting with why preparation is necessary, and ending with a specific timeline to follow.
This guide is suitable for both apartment owners, who can primarily influence their apartment's radiators, and private house owners, who are responsible for the entire heating system, including the boiler or heat pump.
If, after going through this guide, it becomes clear that there is a more serious problem in your system – for example, recurring pressure drops, uneven heating, or unusual noises – we recommend contacting a heating system maintenance specialist who can diagnose the problem more accurately.
Why Should You Inspect Your Heating System Before Winter?
During the summer, the heating system is mostly unused or operating at minimal load – water in the system doesn't circulate, radiators don't heat up or cool down, and minor issues, such as a small leak or accumulated air, go unnoticed as they haven't had a chance to manifest.
When the heating is switched on again in autumn, the pressure and temperature in the system rise sharply, and it's then that the minor problems accumulated during the summer come to light – be it dropped pressure, air in the radiators, a seized valve, or a filter clogged with dirt.
The purpose of preparation is to detect and resolve these issues before the cold weather arrives, when a heating system failure is much more inconvenient and often more urgent to fix than during a calm autumn month.
Apartment Building vs. Private House – Who is Responsible for What?
Before moving on to specific tasks, it's worth clarifying which part of the heating system is actually under your control, as responsibility is divided differently in apartment buildings and private houses.
Apartment Building – Apartment Owner's Responsibility
In an apartment building, where heating comes from a central boiler house or the building's own boiler room, an individual apartment owner cannot influence the overall pressure, pump settings, or the timing of heating activation – these decisions are made by the building management or apartment association. However, every apartment owner can take care of their own radiators: bleed them, check thermostatic radiator valves, and inform the building management if a radiator remains cold in autumn, even though heating is already on in neighbouring apartments.
Private House – Full Responsibility on the Owner
In a private house, the owner is responsible for the entire system – from the boiler or heat pump to the last radiator. This means the preparation checklist is longer, but it also provides more opportunities to spot problems early and solve them yourself.
1. Check System Pressure
Heating system pressure is one of the first things to check in autumn, as low pressure is a very common reason why radiators don't heat evenly or remain cold.
Most domestic heating systems have a pressure gauge on the front panel, which should typically show a range of 1–2 bar (the exact value depends on the specific system and manufacturer's instructions). If the reading is significantly lower, water must be added to the system via a specific filling valve.
An apartment in an apartment building usually does not have a separate pressure gauge, as the pressure is maintained by the central system for the entire building. However, if you feel that the radiators are not heating properly, the cause may still lie in the overall pressure, and it is worth informing the building management.
- Check the pressure gauge on a cold system, not immediately after the heating has been running, as hot water shows higher pressure.
- If the pressure repeatedly drops to the same level within a short period, it likely indicates a leak, not just a natural pressure loss.
- Adding pressure is easy, but if you have to do it often, there is a reason to find and fix the underlying problem, rather than just continuously adding pressure.
2. Inspect the Expansion Tank
The expansion tank is a component of the heating or hot water system that balances changes in water volume as it expands when heated and contracts when cooled. If the expansion tank is not working correctly, the system pressure will fluctuate unstably, and the safety valve may start to release pressure too frequently.
Inside the expansion tank, there is a rubber diaphragm and a gas cushion, whose pressure should be checked periodically – this is usually done through the tank's valve with a special pressure gauge when the system is empty or depressurised. This is a task for which it is wise to call a specialist, as incorrect measurement or filling can worsen the situation.
If you notice that the system pressure fluctuates frequently without an apparent reason or the safety valve is dripping, the expansion tank is one of the first places to check.
3. Bleed the Radiators
At the start of the heating season, bleeding radiators is one of the simplest yet most effective actions you can take yourself. During the summer, air can accumulate in the system, preventing hot water from reaching the top of the radiator and leaving it partially cold.
Bleeding is typically done through the bleed valve located at the top of the radiator – by turning the screw counter-clockwise, air is released until a steady stream of water emerges, after which the valve is tightened again.
- Bleed radiators room by room, starting from the lowest floor if it's a multi-storey house.
- Keep a cloth or small container handy, as a little water always comes out with the air during bleeding.
- If, after bleeding, only air comes out of the radiator and no water at all, the problem may lie elsewhere – contact a specialist.
- Repeatedly rapid air accumulation in a radiator (not just in autumn, but also later in the heating season) may indicate a leak or an issue with the expansion tank.
4. Cycle Valves and Thermostats
During the summer, thermostatic radiator valves usually remain in the same position, which can cause them to seize up – the internal pin gets stuck due to prolonged inactivity, and the valve no longer responds correctly to temperature changes.
Before the start of the heating season, it's advisable to turn each radiator's thermostatic valve fully open and then fully closed a couple of times to free up the pin. This is a simple action that takes only a few seconds per radiator but can prevent the valve from becoming completely seized in autumn.
The same applies to the isolation valves located beneath or beside the radiator, if present, as these can also become stiffer after a long period of inactivity.
5. Clean the Filter and Dirt Separator
Most heating systems, especially in private houses, have a dirt separator or filter installed to prevent rust particles and sludge from reaching the pump and other sensitive system components. Over time, the filter becomes clogged, reducing water flow, which in turn can lead to uneven heating.
Cleaning the filter usually requires isolating the relevant section and opening the dirt separator's cap, through which accumulated dirt can be flushed out. As this operation requires some knowledge of the heating system and correct use of isolation valves, in many cases, it is advisable to have it done by a specialist, especially if the filter has not been cleaned before.
6. Check the Circulation Pump's Operation
The circulation pump is the heart of the heating system, moving hot water from the boiler or heat source to the radiators. If the pump has been idle during the summer, it's worth checking before the heating season whether it starts up and operates smoothly.
Many pumps also have a simple test function or a manually activatable mode that helps ensure the rotor isn't seized. If the pump doesn't start, makes unusual noises, or vibrates excessively, it's a clear sign that it needs specialist attention before the heating season's full load.
In apartment buildings, the circulation pump is typically maintained by a specialist contracted by the building management, so an apartment owner doesn't directly need to deal with the pump's technical condition. However, it's advisable to inform the building management if you notice unusual noises in the heating system that might be related to the pump.
7. Check Room Thermostat and Temperature Control
If you use a programmable room thermostat or smart thermostatic radiator valves at home, it's worth checking their operation before the heating season – batteries may have run out during the summer, and settings might have accidentally changed.
Check that the thermostat shows the correct room temperature (compare with a separate thermometer, for example) and that the schedule, if set, still matches your actual daily routine. A small inaccuracy in temperature measurement can lead to both unnecessary overheating and uncomfortable coolness.
8. Inspect the Boiler or Other Heat Source
For a private house owner, inspecting the heat source – a gas boiler, solid fuel boiler, oil boiler, or heat pump – is the most crucial part of preparing for the heating season, as this is where serious faults often occur, which can leave the home without heat during the coldest times.
For gas boilers, regular servicing by a qualified specialist, covering the burner, heat exchanger, and safety devices, is often legally required. For solid fuel boilers and stoves, it is essential to clean the chimney and flues of soot before the heating season, as this affects both efficiency and fire safety.
For heat pumps, it is advisable to check the outdoor unit for blockages from leaves or other debris, and also clean the air filters if recommended by the manufacturer. The general rule for all heat sources is: if you notice unusual smells, sounds, or a sudden increase in consumption, it's wise to have the appliance inspected by a specialist before the problem worsens.
What are the key inspection points for a heat source?
During an inspection, the quality of combustion, the condition of the heat exchanger, the operation of safety and protection devices, system pressure, and the tightness of connections are typically checked. Such an inspection helps to discover minor problems before they escalate into major breakdowns during the busiest time of the heating season.
When Not to DIY and When to Call a Specialist?
Some of the aforementioned tasks – bleeding a radiator, cycling a valve, checking a pressure gauge – are easily done at home and require no special skills. Other tasks, however, require knowledge of the heating system and the right tools, making it wiser to entrust them to a specialist.
- Measuring and refilling expansion tank pressure – incorrect action can upset system balance.
- Cleaning the filter and dirt separator, especially if it hasn't been done by yourself before.
- Regular servicing and safety checks of the heat source (boiler, heat pump).
- Repair or replacement of the circulation pump if it doesn't start or makes unusual noises.
- Reinstalling a thermostatic valve if it's incorrectly fitted or permanently seized.
- Recurring pressure drops where the cause cannot be found – this likely indicates a leak that needs finding and repairing.
- Problems occurring across multiple apartments in an apartment building – these must be resolved at the building level with the management.
How Can ToruFix OÜ Help?
During heating system maintenance, we check the pressure, expansion tank, filters, pump operation, and valve condition, providing a clear overview of what is in order and what needs attention before the heating season begins. If a radiator or any other part needs replacement, we also assist with radiator replacement and installation.
Timeline: What to Do When, August to October
Heating system preparation doesn't have to be done all at once at the last minute – if you spread the tasks over a few months, you'll have more time to arrange specialist help if needed, before the first cold weather arrives.
August – Planning and Simple Checks
In August, when the heating isn't yet on, it's a good time to perform initial simple checks – inspect the pressure gauge, cycle the thermostatic valves, and note down any issues from the previous heating season that need particular attention this year. If you plan to order regular servicing for your heat source, it's advisable to book an appointment already in August, as specialists typically experience higher demand during autumn.
September – Thorough Inspection
In September, as evenings get cooler, it's worth conducting a more thorough inspection – bleed all radiators, check and top up system pressure if necessary, clean filters, and carry out heat source maintenance if already booked. If you notice anything unusual during this process, there's still plenty of time to resolve the problem before the heating truly kicks in.
October – Test Run Before the Cold
In October, typically before the first truly cold night temperatures, it's worth test-running the heating system briefly – switch the heating on for a short period and go through all rooms, checking that each radiator heats evenly. This way, you'll discover any remaining deficiencies when it's still convenient to fix them, rather than waiting until outside temperatures are below freezing and warmth is truly needed at home.
Summary Checklist Before the Heating Season
If you want to quickly review the entire process, the following checklist will help you remember all the important steps.
- Check system pressure and add water if necessary.
- Have a specialist inspect the expansion tank pressure if it hasn't been done in the last couple of years.
- Bleed all radiators, starting from the lowest floor.
- Cycle all thermostatic and isolation valves to prevent them from seizing.
- Clean the filter and dirt separator, with specialist help if needed.
- Test the circulation pump's startup and listen for unusual noises.
- Check the room thermostat's batteries and settings.
- Order regular servicing for your heat source, especially for gas and solid fuel boilers.
- Perform a test run of the entire system before the first cold weather and monitor for even heating in every room.
10. Check Fuel Supply and Accessories
If your home uses a stove, fireplace, or solid fuel boiler in addition to central heating, it's worth checking your fuel supply before the heating season – ensure that the firewood is sufficiently dry and that you have enough to cover the first colder weeks, when deliveries might be delayed or prices might rise.
Damp firewood does not burn as efficiently as seasoned wood, produces more soot, and increases the need for chimney cleaning during the heating season. If the wood was acquired recently, it may not have had enough time to dry sufficiently before it's needed – therefore, it's advisable to plan your wood supply several months in advance, not just in autumn when the first cold weather has already arrived.
In addition to fuel, it's also worth checking other heating season accessories – such as the radiator bleed key, the hose needed to fill the system, tools for cleaning the filter, and spare parts that have been needed before. If any of these are missing or broken, it's better to replace them before the heating season begins, rather than looking for the right tool just when a radiator suddenly turns cold.
- Check your fuel supply by the end of summer to allow enough time for delivery or drying.
- Ensure that firewood is covered and protected from moisture, as wet wood reduces burning efficiency.
- Locate the radiator bleed key and other necessary tools so they are at hand when first needed.
- If using a stove or fireplace, ensure the chimney is clean and fire-retardant panels or other safety devices are in good order.