# Differential pressure regulator Herz 4002 DN25 (model 1400243), DN25 pressure balancing valve

**URL:** https://aio.lv/en/product--herz-1400243--11785103
**Data updated:** 2026-03-08 22:56 (EET)
**Category:** Heating Radiators
**Manufacturer:** Herz
**Manufacturer code:** 1400243
**EAN:** 9004174454202
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 173.99 €
**Prices and availability valid until:** 2026-07-17 23:59
**Price without VAT (21%):** 143.79 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--herz-1400243--11785103

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 10.07.2026 | free |
| Pickup points | 15.07.2026 | 1.99 EUR |
| Courier delivery to door | 15.07.2026 | 4.99 EUR |

## Summary description

Herz 4002 differential pressure regulator is a DN25 pressure balancing valve designed to maintain a stable differential pressure in heating and cooling systems. Model 1400243 provides automatic pressure stabilization to protect pumps and control valves, reduce hydraulic noise and ensure reliable flow distribution in radiators, manifolds and HVAC circuits.

## Long description

Herz 4002 differential pressure regulator DN25 is a pressure balancing valve designed to maintain a stable differential pressure in heating and cooling systems. Model 1400243 ensures automatic pressure stabilization to protect circulator pumps and control valves, reduce hydraulic noise and secure even flow distribution across radiators, manifolds and HVAC circuits. The valve’s DN25 connection size and compact design make it suitable for residential and commercial installations where reliable hydraulic balancing is required.
Advantages
The differential pressure regulator continuously limits the maximum differential pressure, protecting system components from excessive pressure fluctuations and preventing control valves from hunting. It reduces noise caused by turbulent flow, contributes to longer service life of pumps and valves, and supports stable temperature control by keeping flow rates consistent. Constructed for straightforward integration, the valve offers robust operation under normal heating and cooling system conditions.
Suitable for
Hydronic heating systems with radiators or underfloor heating
Cooling circuits in small commercial buildings
Manifold and distribution header balancing
Protection of circulator pumps and modulating control valves
Key specifications
Connection size: DN25
Function: differential pressure regulation / pressure balancing
Application: heating and cooling hydraulic circuits
Operation: automatic stabilization of differential pressure
Typical benefits: noise reduction, consistent flow distribution, pump and valve protection
How to use
Install the differential pressure regulator in the return or supply line according to system design, ensuring correct orientation and sealing of threaded or flanged connections compatible with DN25 piping. Commission the system by filling and deaerating the circuit, then verify differential pressure across control devices and adjust system flow rates as required. Regular inspection during routine maintenance is recommended to confirm free movement of the regulating element and absence of blockages or excessive wear.
Usage recommendations
Fit the valve in an accessible location to allow inspection and maintenance. Ensure compatibility with system medium and operating temperatures. When integrating with modulating control valves or variable-speed pumps, check that the regulator’s set differential pressure matches the system design parameters to avoid unintended flow restriction.

## FAQ

### How much does the Herz differential pressure regulator 4002 DN25 cost, and is it available for purchase?

The price is 173.99 € (valid at the time of publication and already includes all taxes). The item is available for order — 3 pcs. are in stock, and you can place your purchase right now with delivery across Latvia and Europe or choose pickup at the Riga collection point. We offer favorable purchase terms, including the option to split the payment into convenient monthly installments. Availability and price are updated in real time, so we recommend placing your order in advance.

### If I order this product today, when will I receive my order?

If you place your order today, delivery will be as fast and convenient as possible. You will be able to pick up your order on 10.07.2026 at the Riga pickup point or choose delivery across Latvia and Europe. We carefully inspect every purchase and pack it securely for safe transportation.

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer, Bank cards on-line, Apple Pay, Google Pay, Installment. All transactions are 100% secure and encrypted.

### Can Herz differential pressure regulator 4002 DN25 be purchased with a lease?

Yes, the purchase is available both on credit and with an interest-free installment plan. Learn more about installments and credit options: https://aio.lv/en/payment#b3

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All Herz products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized Herz service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

## Image

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