# Expansion vessel (diaphragm) INVENA CM 8L CW-11-008 — 8 liter capacity

**URL:** https://aio.lv/en/product--invena-cw-11-008--12072619
**Data updated:** 2026-03-12 21:51 (EET)
**Category:** Home Appliance Accessories
**Manufacturer:** INVENA
**Manufacturer code:** CW-11-008
**EAN:** 5907798738144
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 37.99 €
**Prices and availability valid until:** 2026-07-21 23:59
**Price without VAT (21%):** 31.40 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--invena-cw-11-008--12072619

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 16.07.2026 | free |
| Pickup points | 21.07.2026 | 1.89 EUR |
| Courier delivery to door | 21.07.2026 | 4.99 EUR |

## Summary description

Diaphragm expansion vessel INVENA CM 8L (model CW-11-008) is an 8-liter pressure vessel designed for heating and domestic water systems. It features a flexible internal diaphragm separating the air cushion and the system fluid to compensate thermal volume changes, reduce pressure spikes and protect pumps and valves. Suitable for small boilers, heating circuits and closed hydraulic systems.

## Long description

Diaphragm expansion vessel INVENA CM 8L (model CW-11-008) is an 8-liter pressure vessel designed for closed heating and domestic water systems. The internal flexible diaphragm separates the air cushion from the system fluid, allowing the vessel to absorb thermal expansion, reduce pressure fluctuations and protect pumps, valves and pipework. The compact design and corrosion-resistant materials make this expansion vessel suitable for small boilers, heating circuits and auxiliary closed hydraulic installations.
Advantages
The diaphragm design provides fast response to pressure changes while preventing bladder contact with the system fluid, which reduces the risk of contamination and prolongs service life. The 8‑liter capacity is optimized for small domestic systems and secondary circuits, offering effective pressure compensation without excessive space requirements. The vessel’s construction allows for straightforward installation and maintenance in residential and light commercial applications.
Suitable for
Small gas or electric boilers in single-family homes
Secondary heating circuits and radiators
Closed domestic hot water systems
Closed hydraulic circuits in small commercial installations
Key specifications
Nominal volume: 8 liters
Diaphragm-type internal separation between air and fluid
Application: closed heating and domestic water systems
Purpose: compensate thermal expansion and reduce pressure spikes
Compact design suitable for wall- or floor-mounted installation
How to use
Install the expansion vessel on the system return line or at the location recommended by the heating system manufacturer, ensuring correct orientation and secure mounting. Pre-charge the air side to the required pressure for the system (matching the static pressure of the installation) before commissioning. After connection, bleed air from the system and verify operating pressure and tightness. Periodically check the pre-charge pressure and the vessel for signs of external damage or leaks as part of regular system maintenance.
Usage recommendations
Before installation, consult the boiler or system manufacturer’s documentation to confirm appropriate pre-charge pressure and recommended mounting position. Use compatible fittings and isolation valves to allow removal or replacement without draining the entire system. If the diaphragm shows loss of function or leakage is detected, replace the vessel to maintain system protection.

## FAQ

### How much does the INVENA CM 8L expansion vessel CW-11-008 cost, and is it available for purchase?

The price is 37.99 € (valid at the time of publication and already includes all taxes). The item is available for order — 2 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 16.07.2026 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. All transactions are 100% secure and encrypted.

### 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 INVENA 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 INVENA 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/12072619/67557284_large.webp