Radiator Replacement and Installation

The clearest sign is a leak. If moisture appears at the radiator connection or between sections, it's a question of "when," not "if." Heating systems are under pressure, and a small drip often turns into a major leak at the start of the heating season when the system is pressurised. Another common reason is seized or corroded valves: if a radiator can no longer be shut off, subsequent work becomes more complex and risky.

A third reason is loss of heat output. Old radiators, especially in older apartment buildings, are often filled with sediment and dirt internally. The radiator may look fine externally, but its heat transfer capacity has decreased, and the lower part remains cold. In this case, it's worth assessing whether a system flush would help or if it's cheaper to replace the radiator – this decision shouldn't be made over the phone, but based on an on-site inspection.

A fourth reason is renovation and layout changes. If a room gets new finishes, window replacements, or a spatial redesign, it's logical to also replace the radiator and move it to the correct location. A correctly sized radiator installed under a new window eliminates a typical problem with old setups: cold air drafts from below the window, which an old, undersized radiator couldn't mitigate.

• Radiator or connection is leaking, threads are corroded
• Radiator valve or thermostat is seized
• Radiator heats unevenly, the lower part remains cold
• Room doesn't get warm even when the rest of the house is warm
• Renovation is underway, and the radiator's location or size is changing
• Risers are being replaced in an apartment building, and radiators are from the same era

Choosing a radiator isn't just about appearance. Each type behaves differently: how quickly it heats up, how much water it holds, how well it tolerates district heating pressure, and how easy it is to clean later. In practice, the choice comes down to four main types.

Incorrect output is the most common mistake we encounter and fix. An undersized radiator won't be able to heat the room sufficiently, even with the valve fully open. An oversized radiator will constantly operate at partial load, which means uneven temperatures in district heating and frequent boiler cycling in a private home.

When estimating output, we consider room area and ceiling height, number and type of windows, number of external walls, floor level in the building, and the actual system flow temperature. The latter is an important nuance: the output stated on the radiator's packaging applies under manufacturer's test conditions, and in a low-temperature system, the same radiator will emit less heat. This is why we always calculate the solution according to the specific building, not just a general area formula.

Location is as important as output. The classic correct spot is under a window, where the radiator counteracts cold air drafts before they spread into the room. The radiator must remain unobstructed: a long windowsill, thick curtains, or furniture built in front of the radiator will significantly reduce heat output. If obstruction is unavoidable, we account for this when selecting the output.

• Radiator length should cover at least 70% of the window width
• A gap of about 10–12 cm should be left from the floor, and 8–10 cm from the windowsill
• A gap of 3–5 cm should be left from the wall for air circulation behind the radiator
• Higher heat loss is factored in for corner rooms and top floors
• Radiators should not be covered by dense screens or furniture

The work fundamentally follows the same structure, whether we're replacing a single radiator in an apartment or all radiators in a house. The difference lies in the scope and preparation required.

In an apartment building, a radiator is part of a shared heating system, which sets rules for the work. During the heating season, the riser is under pressure, and the radiator cannot simply be removed – closing the riser is required, which is arranged by the apartment association or management company. This is why we recommend planned radiator work be done in summer when heating is off: it's faster, cheaper, and causes less disturbance to neighbours.

Another important nuance is hydraulic balancing. If one apartment owner installs a significantly larger radiator or unilaterally changes the connection scheme, it can affect the heat supply of other apartments on the same riser. We operate based on the logic of the existing system and offer solutions that don't take heat away from neighbours. For major changes, we recommend coordinating the solution with the apartment association.

For apartment associations, we also undertake large-scale radiator replacements: for entire stairwells or buildings, according to an agreed schedule and with resident notification. In such cases, it's sensible to combine the work with riser upgrades – walls and floors are opened only once, and the result is long-lasting. If the building plans a broader heating system upgrade, we also review the heat sub-station and the need for system flushing.

• Planned replacement in summer is faster and cheaper than during the heating season
• Riser closure is agreed with the apartment association or manager
• Connection scheme is not altered at the expense of neighbours' heating
• For associations, we perform work on a schedule, apartment by apartment
• Replacement can be combined with riser upgrades

In a private home, the system is autonomous, offering greater freedom: you can choose the radiator type, connection method, and pipework solution. In new builds, we mostly install radiators with a manifold system, where each radiator has its own pipe – this provides better control and easier maintenance later on. For renovations, we work with the existing pipework and assess whether it can be used or if an upgrade is more sensible.

If a heat pump is the heat source, it's important to consider the lower flow temperature. For the same room, a larger surface area radiator will be needed than with a traditional boiler. An incorrect choice can lead to a situation where the heat pump operates efficiently, but the room remains cool – the problem isn't with the device, but with undersized radiators.

Often, underfloor heating and radiators are combined in private homes: underfloor heating on the ground floor and in wet rooms, radiators in bedrooms and on the first floor. In such cases, we design the solution so that both circuits receive the correct temperature and the system is balanced. We perform underfloor heating work to the same scope – see the underfloor heating installation page.

A thermostatic valve is a small detail with a disproportionately large impact on heating costs and comfort. The thermostat maintains the room temperature at a set level and closes the flow when the room is warm – for example, on a sunny day or during cooking in the kitchen. Without a thermostat, the room continues to be heated, and excess warmth is lost through open windows.

Old thermostats tend to seize, especially if not moved for extended periods. A seized head can leave the radiator either continuously closed or continuously open. In most cases, the thermostatic head can be replaced without draining the system if the valve body itself is in good condition. If the body is also worn, we replace the entire valve.

Balancing is a step that, when skipped, causes the typical complaint: one room is too warm, while another remains cold. Water always takes the path of least resistance, and without adjustment, most of the flow will go to the shortest circuit. By adjusting the return valves, we redistribute flow rates between radiators so that the furthest radiator receives its allocated amount. This is an inexpensive job that often yields immediate results.

• Thermostatic valve for every radiator where technically possible
• Return valve for flow adjustment and radiator isolation
• Air vent plug at the top of the radiator
• Shut-off valves so the radiator can be isolated later
• Circuit balancing after installation

Most later problems arise not from the radiator itself, but from the installation. Below are the mistakes we see most often – most of which are preventable.

• New radiator connected to an old, corroded pipe section that soon fails
• Shut-off valves omitted, requiring system drainage for every subsequent job
• Radiator installed too low or too close to the wall, obstructing air circulation
• Thermostat installed where it's covered by curtains or furniture, leading to incorrect temperature readings
• Fixings installed without considering wall material, causing heavy radiator to sag
• System left unbled, leading to the top part of the radiator remaining cold
• Circuits not balanced, resulting in distant rooms staying cool
• Output chosen solely by area, without considering windows, corner rooms, and system temperature

A cold radiator doesn't always mean it's broken. Diagnosis proceeds by elimination, and the sequence is almost always the same: first air, then the valve, then flow rate, then system blockage.

If the top part of the radiator is cold and the bottom is warm, it indicates air – this is removed via the air vent plug. If the radiator is completely cold but the riser is warm, a closed or seized valve is usually to blame. If the radiator only warms near the connection pipe and otherwise remains cold, it suggests sediment in the radiator or insufficient flow rate.

If all radiators in one part of the house are cold, the problem isn't with an individual radiator, but with the system: pressure, pump, balancing, or the heat source. In such cases, we inspect the entire circuit and, if necessary, recommend system flushing or maintenance. The cause of a cold radiator must be found before replacement – otherwise, the new radiator will also remain cold.

The price is determined by the scope of work and site conditions, not just the number of radiators. The biggest difference comes from whether existing connections are usable or if the pipe section needs upgrading, and whether the system can be partially or completely isolated.

The cheapest option is a planned replacement outside the heating season, where the radiator has functioning shut-off valves and the new radiator fits existing connections. It's more expensive when work must be done during the heating season, valves are missing, pipework is corroded, and connection heights need to be altered. Emergency call-outs for a leaking radiator are a separate service, available 24/7.

We provide the price before work begins and list materials separately on the invoice. For larger projects – an entire apartment or house – we conduct an inspection and provide a written quote. Hourly rates apply, and an overview of work costs can be found in the price list; the exact sum is always determined after an on-site inspection.

• Number and type of radiators and their location on site
• Whether existing connections and valves are usable
• Whether a pipe section needs replacing or connection heights altered
• Whether work is done during or outside the heating season
• Whether riser closure and coordination with the apartment association are required
• Whether it's planned work or an emergency call-out

New radiators don't require much attention, but a few simple habits will significantly extend the system's lifespan. The most important is bleeding at the start of the heating season: after the summer shutdown, air accumulates in the system, and removing it takes a couple of minutes per radiator.

Another tip is to move thermostats even in summer. If the head stays in one position all season, the spindle can seize. A few turns during the off-season keeps the valve moving. Thirdly, it's worth monitoring system pressure – a continuous drop means there's a leak somewhere, and finding it early is cheaper than later.

In an older system where radiators are new but pipework is old, consider a heating system flush. A new radiator will quickly collect sediment from old pipework and lose some of its output. We perform flushing and maintenance as part of our heating system maintenance service.

• Bleed radiators at the start of the heating season
• Move thermostat heads even outside the heating season
• Monitor system pressure and react to continuous drops
• Do not cover radiators with dense screens or furniture
• Consider flushing an old system before installing new radiators

We perform radiator work daily in apartments, private homes, and for apartment associations in Tallinn and Harjumaa. This means we are familiar with both old apartment building riser solutions and new private home manifold systems, and can anticipate specific nuances on any given site.

We provide the price and scope of work before starting, and list materials separately on the invoice. We guarantee both the work performed and the materials we install, and issue a proper invoice suitable for submission to apartment associations or insurance companies. If we see that radiator replacement won't solve the problem – for example, if the real cause is system balancing or the heat sub-station – we'll honestly say so and offer the correct solution.

If your radiator is leaking now, don't wait until morning: close the valves if possible and call. Our emergency service operates 24/7. For planned replacements, we agree on a suitable time and conduct an inspection, based on which you'll receive a clear quote.