EK distributors vs. distributors with flow meters - differences
Introduction: why the choice between EK distributor and flow meter distributor is a crucial decision
When designing a floor heating system, sooner or later every designer, installer or informed investor is faced with the question: should I use a simpler distributor with EK valves (sometimes also referred to as a shut-off valve distributor), or should I go for the more expensive distributor with flow meters (rotameters)? At first glance, this seems to be a minor detail, but in reality, this choice significantly affects the way the system is balanced, the comfort of future maintenance, the accuracy of heat distribution in individual rooms, and ultimately the user's satisfaction with the entire heating system for decades to come.
In practice, I often encounter the situation where customers simplify this topic to the question of price - a distributor with flow meters is more expensive, so many decide to save money and choose the cheaper EK version. Sometimes this is a reasonable decision, but at other times it comes back to haunt them at the first balancing of the system, when the installer realizes that without flow meters, he cannot reliably set an even flow to dozens of meters long circuits in different rooms. In this article, we will examine the differences in depth - technically, practically and economically - so that you can make an informed decision for a specific project.
What is an EK distributor and how does it work
The designation EK is commonly used in heating technology catalogs for distributors equipped with simple regulating (shut-off) valves without built-in flow measurement. Structurally, it is a distribution and return branch (supply and return), with manual or thermostatic heads on the supply branch, which are used to regulate the flow to individual floor heating circuits.
Regulation with an EK distributor works on the principle of throttling the flow using a valve - by turning the control element, the cross-section through which the heat transfer fluid flows is changed, and thus the hydraulic resistance of the circuit is changed. The problem is that without a flow meter, the installer can only estimate how many liters per minute actually flow through a given branch. The setting is done "blindly" - either according to the number of valve turns recommended by the manufacturer (so-called preliminary setting according to tables), or according to the temperature feeling in the room, which is an extremely inaccurate and very time-consuming method, because floor heating has a high thermal inertia and a change in setting will only be noticeable in the room after hours, sometimes days.
Construction of an EK distributor
EC distributors are mostly made of brass, sometimes with nickel plating for resistance to deposits and easier cleaning. The distributor body contains:
- Main distribution pipe with branches for individual circuits (usually 2 to 12 circuits)
- Ball shut-off valves at the beginning and end of the distributor for isolation from the rest of the system
- Throttling (regulating) valves on the supply branch for each circuit
- Drain and air vent valves usually at both ends
- Mounting brackets and consoles for mounting in the distributor cabinet
The advantage of this construction is its simplicity, lower price and lower failure rate - the fewer movable and precise mechanical parts, the less can go wrong. The disadvantage is precisely the lack of direct visual flow reading.
What is a distributor with flow meters and what is its benefit
A distributor with flow meters (rotameters) has transparent cylinders with a float built into the supply branch instead of simple throttling valves. The float rises or falls according to the current flow of the heat transfer fluid. On the scale around the cylinder (usually in the range of 0 - 5 l/min or 0 - 4 l/min depending on the manufacturer), it is possible to directly read how many liters per minute flow through a given circuit.
This solution fundamentally changes the way the system is balanced. The installer no longer has to wait hours or even days for the temperature response in the room - he can immediately see what the current flow is and can easily adjust it by turning the regulating ring directly on the body of the flow meter. The calculation of the required flow for each circuit is already done in the project according to the heat loss of the room, the length of the circuit and the temperature drop, and the installer then simply sets the actual values according to the project documentation.
How to read and set the flow meter
The flow meter is a transparent tube (most often made of transparent plastic or glass) with a float inside. The float rises to a height corresponding to the current flow due to the flowing water - the higher the flow, the higher the float rises. The reading is taken in the middle of the float (or according to the manufacturer's marking) against the scale printed on the outer wall of the tube.
Setting the desired flow is done by turning the regulating ring at the bottom of the flow meter, which changes the flow cross-section - in principle, it is still throttling, but with immediate visual feedback. This is a fundamental difference compared to the EK distributor, where the regulator also throttles the flow, but without feedback.
Graphical comparison of the regulation principle
Practical impact on the balancing of the floor heating system
In practice, hydraulic balancing of floor heating is one of the most important and at the same time most underestimated tasks when putting the system into operation. Each floor heating circuit has a different length, a different pipe diameter, passes through a different room with a different heat loss - and therefore requires a different flow of heat transfer fluid to deliver exactly the amount of heat that the room needs.
For example, if the bathroom has a 45 m circuit and the living room has two circuits of 80 m each, you cannot expect both rooms to be heated evenly with the same valve setting. The shorter circuit offers less hydraulic resistance, so with the same setting, more water flows through it than is desirable - the room overheats, while the longer circuit is underdimensioned and the room is colder than it should be.
Practical scenario: a family house with 6 circuits
Let us take a concrete example that we often encounter in the realization of family houses. We have a distributor with 6 circuits: kitchen (60 m), living room - 2 circuits (75 m and 82 m), bedroom (55 m), bathroom (40 m) and hallway (35 m). The project determines that at a given temperature difference (e.g. 40/30 °C), the flow in the individual circuits should be:
| Room | Loop length | Recommended flow |
|---|---|---|
| Kitchen | 60 m | 1.8 l/min |
| Living room - loop 1 | 75 m | 2.4 l/min |
| Living room - loop 2 | 82 m | 2.6 l/min |
| Bedroom | 55 m | 1.6 l/min |
| Bathroom | 40 m | 1.2 l/min |
| Corridor | 35 m | 1.0 l/min |
With a distributor equipped with flow meters, the installer simply sets the adjustment ring for each loop so that the float indicates the exact desired value - the entire balancing process takes about 15-30 minutes and is completed on the same day the system is started. With an EK distributor without flow meters, we would have to perform repeated temperature measurements in the rooms over several days, adjust the valve settings, wait for the temperatures to stabilize, and repeat the process - which is extremely time-consuming in practice, and many construction companies simply do not do it properly due to time and economic constraints. The result is then customer complaints about uneven heating, which is very difficult to resolve afterwards.
Accuracy and limitations of individual solutions
It is important to note that flow meters are not 100% accurate either - the typical accuracy of rotameters is within a tolerance of approximately ±10% of the scale range, which is, however, completely sufficient for the needs of floor heating. Much more important is the fact that they provide immediate and repeatable feedback, which the EK solution cannot do in principle.
With EK distributors, it is sometimes possible to achieve an approximate balancing using a table of valve turn counts from the manufacturer (e.g., "2.5 turns = approximately 2 l/min at a given pressure drop"), but this method is sensitive to the actual pressure drop in the system, which can differ from catalog conditions. In practice, this method is more suitable as an approximate starting point rather than a final solution.
When is an EK solution sufficient
I do not want to create the impression that EK distributors are unsuitable or bad solutions - they have their place and work without problems in many implementations. They are suitable especially in the following situations:
- Small apartments or houses with a small number of loops (2-4), where the loop lengths are similar and the differences in room heat losses are not significant
- Combination with room thermostats and actuators on each loop, which solve temperature regulation directly at the point of use, making the accuracy of the flow at the distributor less critical
- Budget-constrained projects, where the investment is better focused on other system components (e.g., a better heat source, better building insulation)
- Temporary or provisional solutions, renovations with a limited budget
When it is worth investing in flow meters
On the other hand, I definitely recommend flow meters in the following cases:
- Larger houses with many loops of different lengths (5 or more loops with significant differences in length)
- Projects where emphasis is placed on precise comfort and even heating (e.g., passive or low-energy houses with a precisely designed thermal balance)
- Heat pump systems, where correct hydraulic balancing is crucial for the efficiency of operation and achieving the declared COP
- Implementations where future layout changes or room use changes are planned (e.g., basement areas, renovations)
- Situations where the investor expects a simple possibility to check and adjust the system by their own means without the need to call a service technician
Economic comparison - how much it really costs
The price difference between an EK distributor and a distributor with flow meters in practice ranges in the tens of euros per distributor, specifically depending on the number of loops and the manufacturer. For a distributor with 5-6 loops, the price difference is in the range of 40-100 €, and for larger distributors with 8-12 loops, the difference naturally increases proportionally with the number of flow meters.
When we compare this to the total costs of implementing a floor heating system in a family house (often in the range of thousands to tens of thousands of euros for the entire system including pipes, insulation, screeds, and the heat source), the price difference of the distributor represents a relatively small percentage of the overall budget. Despite this, it has a decisive impact on how well the system will function throughout its entire lifecycle, which is counted in decades for floor heating.
Hidden costs of a poorly balanced system
It is important to realize that a poorly balanced system is not just a matter of comfort, but also of energy efficiency. If some loops receive more heat than needed, and others less, the result is:
- Higher energy consumption - the heat source has to supply a higher temperature to "heat up" the underdimensioned loops, which unnecessarily overheats the others
- Lower efficiency of the heat pump - a higher required output temperature means a lower COP and higher operating costs
- Uneven comfort - some rooms are too warm, others are cold, leading to complaints and dissatisfaction
- Faster wear of some components due to uneven system loading
These hidden costs can accumulate over the years of operation and may exceed the original savings from choosing a cheaper EK distributor.
Graphical representation of uneven heating in case of poor balancing
As can be seen from the diagram, without accurate balancing, the differences between rooms can be as much as 5-7 °C, which is a significant problem in terms of living comfort. With a properly set system using flow meters, these differences should be minimized to values corresponding to the designed temperatures of the individual rooms (e.g., the bathroom is intentionally warmer, the bedroom is intentionally cooler according to individual preferences, but not due to a regulation error).
Combination with other regulation components
The distributor - whether EK or with flow meters - is only one part of the entire regulation chain of the floor heating system. In practice, it is often combined with:
- Actuators - electrothermal heads that open and close the flow to the loop based on a signal from the room thermostat. These handle the switching on and off of heating in a given room, but do not replace the hydraulic balancing of the basic flow.
- Room thermostats - measure the temperature in the room and control the actuators. The more accurately the system is hydraulically balanced, the less the thermostats have to "fight" with uneven heat distribution.
- Mixing groups/pump groups - handle the temperature of the water supplied to the distributor, which is a different level of regulation than the flow in individual loops.
It is important to understand that actuators and thermostats handle time-based regulation (when the circuit should heat), while the setting on the distributor (EK valve or flow meter) handles quantity regulation (how much should flow through the given circuits when open). Both levels of regulation are necessary and complement each other - one does not replace the other.
Installation and space requirements - is there a difference?
From an installation perspective, both types of distributors are very similar - they differ mainly in the heads/valves on the supply branch, while the return (return) branch is structurally almost identical. Flow meter distributors are slightly bulkier in size due to the transparent rollers of the flow meters, which must be considered when selecting the distributor cabinet.
When designing the cabinet, I recommend always allowing for a slightly larger reserve in depth and height, especially if a transition from EK to a flow meter solution is planned in the future or additional circuits are to be added. In our range you will find, for example, Wall-mounted distributor cabinet N-MAX 1 - 450 mm for smaller installations with a limited number of circuits, or a larger Wall-mounted distributor cabinet N-MAX 5 - 1200 mm for more extensive systems with a larger number of circuits and flow meters, where sufficient space is needed for convenient operation and reading of values. An alternative of medium size is Wall-mounted distributor cabinet N-KLASIK 2 - 535 mm, which is suitable for medium-sized installations. This decision is discussed in more detail in the article How to choose a distributor cabinet - dimensions and placement.
Installation process in short
Regardless of the type of distributor, a similar sequence of steps applies during installation:
The last step - hydraulic adjustment - is precisely the part where the difference between EK and flow meter solutions becomes most apparent. A detailed installation procedure can be found in the separate article Installation of a distributor and distributor cabinet step by step.
Connection with floor insulation and overall system quality
Hydraulic adjustment only makes sense if the rest of the underfloor heating system is also implemented properly. One of the often underestimated elements is floor insulation, which is laid under the screed and serves two functions - thermal insulation (prevents heat loss downwards and into the side walls) and acoustic (dampens the transmission of footstep noise between floors).
If the floor insulation is of poor quality or improperly laid, heat is lost in an undesirable direction and even a perfectly adjusted system with flow meters cannot effectively compensate for these losses - the temperature of the heating water must be increased, which increases operating costs. In our range you will find, for example, Floor insulation - 1.5 m; 6 mm, 75 m pack or a smaller pack Floor insulation - 1.0 m; 6 mm, 12.5 m pack for smaller repairs or additions. The correct laying of this material is discussed in detail in the article Floor insulation - what it is for and how to lay it correctly.
Service and maintenance - differences in practice
In terms of long-term maintenance, both types of distributors have similar requirements - regular checking of the tightness of connections, checking the functionality of air vents, occasional bleeding of the system after filling with water, checking actuators and replacing them in case of failure (the lifespan of an actuator is usually stated as 80,000 - 100,000 switching cycles, which in normal operation corresponds to approximately 8-15 years of use).
The difference arises when checking and possibly correcting the adjustment - with a flow meter distributor, it is sufficient to take one look at the scales to determine whether everything is in order and the flows correspond to the original setting. With an EK distributor, this check cannot be done visually - you would either have to trust that the setting has not changed (the valves can gradually "go out of tune" due to vibrations, thermal expansion of the material or careless intervention, for example when cleaning the cabinet), or you would have to resort to the time-consuming measurement of room temperatures again.
From practice, I can confirm that the possibility of quick visual inspection is one of the main reasons why many experienced installers recommend flow meter distributors even despite the higher purchase price - they save time in service interventions in the long run and allow for quick diagnostics if a problem appears in the system (for example, a clogged circuit, an air bubble, or a leak). More information about typical problems can be found in the article Common distributor faults and their solutions and about the inspection process in the article Maintenance and service of the heating system distributor.
How to decide - summary of criteria
When making the final decision, I recommend considering the following factors:
| Criterion | EK distributor | Distributor with flow meters |
|---|---|---|
| Purchase price | Lower | Higher (by approx. 40-100 € depending on the number of circuits) |
| Accuracy of adjustment | Low, estimated | High, measurable and repeatable |
| Time needed for adjustment | Long (days) | Short (tens of minutes) |
| Suitability for small systems (2-4 circuits of similar length) | Yes | Yes, but not necessarily needed |
| Suitability for larger systems (5+ circuits of different lengths) | Limited | Recommended |
| Simplicity of visual inspection during service | No | Yes |
| Suitability for systems with heat pumps | Limited | Recommended |
| Space requirements in the cabinet | Lower | Slightly higher |
The specific choice of a manifold should also be based on the overall heating system project - how many circuits you will need and what their parameters should be, you will find out in the article How many circuits and outlets do I need on the manifold, while the general selection criteria are discussed in the article How to choose a manifold for floor heating.
The influence of differential pressure on the accuracy of a shut-off valve without a flow meter
One technical detail that is often overlooked when comparing EK and flow meter manifolds is the influence of variable differential pressure in the system on the accuracy of the setting. Tables from manufacturers such as "2.5 turns = 2 l/min" are always valid only for one specific pressure drop, which is stated in the measurement conditions (most often 10 or 20 kPa). In real operation, however, the differential pressure at the manifold changes - it fluctuates depending on how many circuits are currently open, how the circulation pump is working (especially if it does not have constant pressure regulation), and how the hydraulic resistance in other parts of the system changes.
A shut-off valve without a flow meter does not indicate this change in any way - its position (number of turns) remains the same, but the actual flow through it changes according to the current pressure drop. A flow meter, on the other hand, shows the real current state regardless of what pressure is currently in the system, because it measures the direct physical manifestation of flow (buoyancy on the float), not a derived value from the valve position.
That is why, in systems sensitive to accuracy (for example, in heat pumps, where excessive flow in one circuit reduces the pressure reserve for the others and causes underheating of more distant rooms), it is recommended to combine a flow meter manifold with a circulation pump in constant differential pressure mode or at least with a balanced hydraulic design of the piping already in the project. A flow meter alone will not prevent pressure fluctuations - it will only allow them to be compensated manually over time, while with an EK valve, this compensation would require repeated temperature measurements and recalculation of the setting from scratch.
Frequently asked questions about EK and flow meter manifolds
Can an EK manifold be replaced with a flow meter one without interfering with the screed?
Yes, provided that the distances of the connections and the type of circuit connections are compatible (most often euroconus or another standardized connection), it is possible to replace only the manifold itself without interfering with the underfloor piping. However, it is necessary to check whether the new unit physically fits into the existing manifold cabinet, as flow meter versions are usually slightly larger.
Is it possible to combine EK valves and flow meters on one manifold?
In principle, yes, some manufacturers offer modular solutions where a flow meter can be installed on selected circuits (for example, the longest or most critical ones) and the rest can remain with simple valves. This is not used very often in practice, however, as the price difference when equipping the entire manifold with flow meters is not significant enough to justify complicating the selection and installation.
Does the type of manifold affect the lifespan of the entire floor heating system?
Directly no - the material quality and lifespan of the manifold itself (brass, seals, valves) does not depend on whether it has or does not have flow meters. Indirectly yes, however, because a properly regulated system (which flow meters significantly facilitate) means more even loading of individual circuits and less thermal stress on materials, which can ultimately extend the lifespan of the entire system.
Do I need thermostatic heads with flow meters, or is just setting the flow enough?
Flow meters solve the basic (static) hydraulic balancing - they ensure that the correct amount of water flows through when the circuit is fully open. For dynamic temperature regulation during the day (for example, night setback, different demands in different rooms), it is advisable to supplement the system with thermostatic heads or electrothermal actuators controlled by room thermostats. Both systems complement each other and it is recommended to combine them.
Is a flow meter manifold worth it in a renovation, where the piping is already in place?
Yes, especially if the original installation was not properly balanced and you experience uneven heating in individual rooms. Replacing the manifold is a relatively non-intrusive intervention (provided the connections are compatible), which can significantly improve comfort without the need to interfere with the floor.
How long does balancing a system with flow meters take in practice?
In a typical family house with 6-10 circuits, the actual flow setting on the manifold (assuming you have the design values available) takes approximately 20-40 minutes. It is advisable to check the room temperatures after a few days of operation and make fine adjustments if necessary, as the actual behavior of the building may slightly differ from the design assumptions in the project.
Conclusion
Choosing between an EK manifold and a flow meter manifold is not just a matter of a few dozen extra euros in the budget, but a decision that will influence the comfort, energy efficiency, and ease of maintenance of the heating system for decades to come. For small and simple installations with a few similarly long circuits, an EK solution may be fully sufficient and economically justified. For larger projects, systems with heat pumps, or where precise comfort and easy future diagnostics are emphasized, I strongly recommend investing in a manifold with flow meters.
When selecting a specific model and related accessories - including a suitable manifold cabinet, mounting materials, or step insulation - do not hesitate to look at other articles in our Knowledge Center or go directly to the category manifolds and accessories, where you will find the current product range along with the technical parameters needed for the correct selection.
Do you have a question about this topic?
Not sure how to decide or dealing with a specific situation in your home? Write to us - we are happy to help.