# Expansion Vessel Reflex S 25 L for Solar Systems, Reflex 9704200

**URL:** https://aio.lv/en/product--reflex-9704200--12074004
**Data updated:** 2026-04-24 17:44 (EEST)
**Category:** Solar Panel Accessories
**Manufacturer:** Reflex
**Manufacturer code:** 9704200
**EAN:** 4036705109928
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 78.99 €
**Prices and availability valid until:** 2026-07-10 23:59
**Price without VAT (21%):** 65.28 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--reflex-9704200--12074004

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 02.07.2026 | free |
| Pickup points | 07.07.2026 | 1.99 EUR |
| Courier delivery to door | 07.07.2026 | 4.99 EUR |

## Summary description

Reflex Expansion Vessel S with 25 L capacity designed for solar thermal and hot-water systems. The vessel provides hydraulic compensation of pressure changes in closed circuits, helps protect components from overpressure and reduces system water losses. Suitable for installation in residential or commercial solar heating loops where a compact 25‑litre expansion vessel is required.

## Long description

The Reflex Expansion Vessel S 25 L for Solar Systems is a diaphragm-type expansion vessel designed to accommodate volume changes and pressure fluctuations in closed solar thermal and hot-water circuits. With a nominal capacity of 25 litres, it provides hydraulic compensation to protect pumps, heat exchangers and piping from excessive pressure and to reduce water loss due to frequent venting or leakage. The compact design and solar-specific compatibility make it suitable for domestic and small commercial solar heating installations where a moderate expansion volume is required.
Advantages
This expansion vessel uses a pre-charged elastomer diaphragm to separate the system fluid from the gas cushion, ensuring reliable pressure buffering and minimizing air ingress into the system. Its 25 L volume offers a balance between compact installation footprint and sufficient buffer capacity for many residential solar loops. The vessel's construction reduces maintenance frequency by lowering the risk of overpressure events and stabilizing system operation under temperature-driven volume changes.
Suitable for
Domestic solar thermal systems (solar collectors and storage tanks)
Small commercial or light industrial solar heating circuits
Closed-loop hot-water systems with moderate expansion requirements
Installations where a compact expansion vessel is needed due to space constraints
When it may not be suitable
This 25 L vessel may not be adequate for large-scale solar arrays, district heating connections, or systems with very high fluid volumes and wide temperature ranges where a larger expansion capacity is required. It is not intended for open systems or applications requiring special materials compatibility beyond standard solar heat-transfer fluids.
Key specifications
Nominal volume: 25 litres
Diaphragm (membrane) type, pre-charged gas cushion
Application: closed solar thermal and hot-water circuits
Typical mounting: wall or bracket-mounted compact vessel
Function: hydraulic pressure compensation and overpressure protection
How to use
Install the expansion vessel in the return line or a recommended location within the solar circuit where it can effectively absorb volume changes. Pre-charge the gas side to the system’s static fill pressure according to the installer or manufacturer instructions, and verify the system charge after filling and commissioning. Regularly check the vessel pressure and visual condition as part of routine system maintenance and before winter operation to ensure the diaphragm remains intact and the pre-charge is within specification.
What to consider before purchase
Confirm required expansion volume based on the system’s fluid volume and maximum temperature range
Check compatibility with the heat-transfer fluid used in the solar loop
Ensure available installation space and mounting options match the vessel’s compact dimensions
Verify recommended pre-charge pressure and any local regulations or installer requirements
Usage recommendations
For reliable performance, have a qualified installer size and set the pre-charge correctly during commissioning. Periodic monitoring of vessel pressure and occasional inspection of connections will help maintain system efficiency and protect components from pressure-related damage.

## FAQ

### How much does the Reflex Expansion Vessel S 25 L 9704200 cost, and is it available for purchase?

The price is 78.99 € (valid at the time of publication and already includes all taxes). The item is available for order — 16 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 02.07.2026 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 Reflex Expansion Vessel S 25 L 9704200 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 Reflex 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 Reflex 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

https://aio.lv/img/cache/product/12074004/67558522_large.webp