What you should clarify before buying
Checklist: Review these points before purchasing
- →Count the number of heating circuits — each separate room area with its own pipe circuit counts as one circuit
- →Check pipe diameter: Standard UFH pipes are 16×2 mm or 17×2 mm — manifold connections G ¾" or G 1" must fit
- →Clarify heat source: heat pump (max. 35–45 °C flow temperature) or gas heating (max. 55 °C) — both are compatible with stainless steel manifold
- →Determine installation location: flush-mounted distribution box or wall-mounted? Standard box fits 2 to 12-circuit distributors
- →Check water quality: soft water (< 300 mg/l carbonate hardness) extends service life — stainless steel is significantly more tolerant than brass here
Stainless Steel vs. Brass: Why the Material Matters
The heating circuit distributor is the heart of a radiant floor heating system – it distributes the heating water to all circuits and must operate reliably for 20–30 years. The choice of material between stainless steel and brass is the most important decision.
Stainless Steel vs. Brass: The Complete Comparison
| Criterion | Stainless Steel (V2A / 1.4301) | Brass (CW617N) |
|---|---|---|
| Corrosion Resistance | Very high — no dezincification | Low — zinc leaching in soft water |
| Water Quality | All water hardnesses 0–25 °dH | Only recommended for > 8.4 °dH (DVGW W 551) |
| Lifespan | 25–35 years | 10–20 years (depending on water hardness) |
| PZH Certification | Yes (DIN EN 1264-4) | Partial |
| Price 6-circuit distributor | 80–120 € | 55–80 € |
| Cleaning & Maintenance | Very easy — acid-resistant | Limescale deposits possible |
| Compatible with heat pump system | Yes — even at pH 6.5–8.5 | Risky below pH 7 |
| Recommendation | Recommended for all new installations | Only for existing buildings with good water |
Why brass distributors can become more expensive despite a lower purchase price
- Soft water (< 8.4 °dH): Zinc corrosion (dezincification) → cracks after 8–12 years
- Replacement costs for distributor + installation: 400–800 € → exceeds initial savings
- Heat pumps produce slightly acidic condensate → accelerates brass corrosion
- PZH certification (suitability test) only available for selected brass qualities
How many circuits do I need? Quick Guide
| Total heating area | Typical circuits | Recommended distributor | Note |
|---|---|---|---|
| up to 40 m² | 2–3 circuits | 2- or 3-circuit | Small apartment, bathroom + 1–2 rooms |
| 40–80 m² | 3–5 circuits | 4- or 5-circuit | Condo, small single-family home |
| 80–130 m² | 5–8 circuits | 6- or 8-circuit | Most common size in single-family homes in Germany |
| 130–200 m² | 8–10 circuits | 8- or 10-circuit | Large single-family home, multi-family home floor |
| over 200 m² | 10–12 circuits (or 2× distributors) | 12-circuit or cascade | Commercial, multi-family home |
Purchase Checklist: What a good distributor must offer
Integrated Flowmeters
Flowmeters per circuit for hydraulic balancing according to GModG § 60. Without flowmeters: external balancing costs 300–600 € in labor.
Ball Valves with Shut-off
Each circuit can be individually shut off — for maintenance, expansion, and repair without depressurizing the entire system.
Thermometers Flow + Return
Temperature display on flow and return allows for spread control and quick fault diagnosis without measuring instruments.
PZH Certification
Suitability test certificate confirms conformity with DIN EN 1264-4. Important for screed layer's warranty and insurance claims.
Standards & Certificates: What do they mean?
| Standard / Certificate | What it means | Important for |
|---|---|---|
| DIN EN 1264-4 | European standard for underfloor heating system components — pressure resistance, materials, connections | All new installations DE/AT/CH |
| PZH (Quality Seal) | Building Services Test Mark — voluntary suitability test beyond the standard | Quality assurance, insurance |
| VDI 6000 | VDI guideline: Equipment for drinking water installations — also applies to heat pump systems | Heat pump integration |
| DVGW W 551 | Drinking water hygiene guideline — limits materials for water < 8.4 °dH | Brass distributor suitability |
| GModG § 60 | Mandatory hydraulic balancing (from July 2026, previously GEG § 60) | All centrally heated buildings DE |
Price Overview Stainless Steel Manifolds & Accessories 2026
| Product / Configuration | Price |
|---|---|
| Stainless steel manifold 2 circuits | from €50 |
| Stainless Steel Manifold 4 Circuits | from €65 |
| Stainless steel manifold 6 circuits | from €80 |
| Stainless steel manifold 8 circuits | from €100 |
| Stainless Steel Manifold 12 Circuits | from €130 |
| Ball valve set (2 pieces, with insulation) | €24 |
| Flush-mount distribution box (fits 2–12 circuits) | 42 EUR |
| Bleed valve (per piece) | €8 |
| Actuator E30NC-230 (per heating circuit) | €9.50 |
| Complete set 4 circuits (manifold + ball valve + box) | approx. €131 |
| Complete set of 6 circles with actuators (6×) | approx. €203 |
| Comparison: Brass Manifold 6 Circuits (Brand X) | from €45 |
| Additional Costs Stainless Steel vs. Brass (6-circuit) | approx. +€35 — recouped in 5 years due to longer lifespan |
Frequent Questions for Heating Circuit Manifold Buying Advice
Brass distributors are cheaper (from €45), but they react to acidic or soft water in modern heating systems, leading to zinc leaching (dezincification). This results in deposits, clogged flow meters, and in the worst case, leaks after 8–12 years. Stainless steel (V4A/1.4401) is completely corrosion-resistant, water-pH-neutral, and lasts 25+ years if installed correctly. The additional cost of €30–40 for a 6-circuit distributor is amortized within the first 5 years.
As a rule of thumb, there is one heating circuit per room (or per room area exceeding 20 m²). An open living/dining area of 40 m² requires 2 circuits, a bathroom 1 circuit. Observe maximum circuit length: for 16×2 mm pipes, max. 80–100 m per circuit. The exact number of circuits can be found in the underfloor heating circuit plan from the screed layer. When in doubt, choose one extra circuit — unused connections are simply sealed with plugs.
For all new builds and refurbishments, we strongly recommend using flow meters. Without a flow meter, hydraulic balancing is not possible—GEG (German Buildings Energy Act) § 60 mandates it for new installations and heating system replacements. The additional cost for integrated flow meters is approximately €5–8 per circuit and saves 10–20% in heating costs through uniform heat distribution. Retrofittable flow meters are available but are more expensive than integrated ones.
PZH (Polish Centre for Testing and Certification / Polish Testing Institute) is an independent European certification body that tests heating components according to EN ISO 11855 and EN 14336. A PZH certificate confirms: correct material composition (genuine V4A stainless steel), pressure resistance of 6 bar at 70 °C, and tightness of all connections. The certificate is particularly important for warranty claims against the developer and for insurance purposes.
Yes. All manifolds with standard connections (M30×1.5 thread) are compatible with commercially available actuators. Recommended: Engo E30NC-230 (€9.50 per piece, 230V). With actuators and one room thermostat per circuit, you achieve individual room control in accordance with GEG § 61. Installation is tool-free (screw on), no soldering or pressing required.
Yes. Stainless steel heating circuit manifolds are ideal for heat pump systems with low-temperature flow (30–45 °C). Important: Flow rates must be adjusted for the heat pump's small temperature spread (ΔT 5–8 K instead of 10 K for gas). Hydraulic balancing with flow meters is particularly critical for heat pump systems—the manifold with integrated flow meters allows for precise adjustment.
Stainless steel heating circuit distributor
Bestseller
5.0(7)
Zum Produkt →
Configurable Heating Circuit Manifold Set | Underfloor Heating Set Discount
Heating circuit manifold
€108,67
5.0(6)
Zum Produkt →
Thermoelectric actuator Engo E30NC-230 for underfloor heating
Actuator
€9,50
5.0(6)
Zum Produkt →
Heating circuit manifold with top meter
Heating circuit distributor
ab€49,69
5.0(2)
Zum Produkt →
Compression ring screw connection 3/4" Eurocone
Connection screw
ab€1,33