# Temperature sensor for connecting hot water cylinder to boiler Vaillant 306257

**URL:** https://aio.lv/en/product--vaillant-306257--11825870
**Data updated:** 2026-03-09 11:15 (EET)
**Category:** Home Appliance Accessories
**Manufacturer:** Vaillant
**Manufacturer code:** 306257
**EAN:** 4024074431450
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 90.99 €
**Prices and availability valid until:** 2026-07-16 23:59
**Price without VAT (21%):** 75.20 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--vaillant-306257--11825870

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 07.07.2026 | free |
| Pickup points | 10.07.2026 | 1.99 EUR |
| Courier delivery to door | 10.07.2026 | 4.99 EUR |

## Summary description

Wired temperature sensor Vaillant 306257 designed for connection between a hot water storage cylinder (buffer/accumulator) and a Vaillant boiler. Provides temperature measurement for domestic hot water control and boiler regulation. Intended for integration into heating systems to enable accurate temperature monitoring, safe operation and efficient control of hot water production.

## Long description

Wired temperature sensor Vaillant 306257 is designed to connect a hot water storage cylinder (buffer/accumulator) to a Vaillant boiler to provide continuous and accurate temperature measurement. The sensor supplies temperature data used by the boiler control system to regulate domestic hot water production, optimize heating cycles and ensure safe operation of the system. It is intended for integration into central heating installations where reliable cylinder temperature monitoring is required.
Advantages
The sensor delivers stable and precise temperature readings suitable for boiler regulation and hot water control without wireless interference. Its wired connection ensures consistent communication with the boiler control unit, supporting efficient operation and reduced energy consumption. The device is compatible with Vaillant systems intended for use with external cylinder sensors and is built to meet common installation standards used in residential heating setups.
Suitable for
 Monitoring temperature of domestic hot water cylinders (buffers/accumulators)
 Integration with Vaillant boilers for regulated hot water production
 Use in residential central heating systems requiring external cylinder sensing
 Replacement of a malfunctioning wired cylinder temperature sensor
Key specifications
 Type: Wired temperature sensor for hot water cylinder connection
 Application: Domestic hot water temperature measurement and boiler regulation
 Compatibility: Designed for use with compatible Vaillant boiler control systems
 Mounting: Cylinder probe/immersion or surface-mounted arrangement depending on installation requirements
 Signal type: Analog temperature signal suitable for boiler control inputs
How to use
Install the sensor according to the boiler and cylinder manufacturer instructions, locating the probe in the designated sensor pocket or mounting position on the hot water cylinder to obtain representative temperature readings. Connect the sensor wiring to the boiler control terminal specified for cylinder/secondary circuit temperature input, ensuring correct polarity and secure connections. After installation, verify communication by checking the boiler control display or diagnostics for the cylinder temperature value and perform any required configuration or calibration per the boiler manual.
Usage recommendations
Ensure the hot water cylinder has an appropriate sensor pocket or mounting point; use proper cable routing and strain relief to protect the wired connection. During maintenance or replacement, isolate power to the boiler and follow safety procedures. Consult the Vaillant boiler manual or a qualified heating engineer for compatibility checks, installation details and any configuration steps required to integrate the sensor into the existing control system.

## FAQ

### How much does the Temperature sensor Vaillant 306257 cost, and is it available for purchase?

The price is 90.99 € (valid at the time of publication and already includes all taxes). The item is available for order — 20 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 07.07.2026 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 Temperature sensor Vaillant 306257 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 Vaillant 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 Vaillant 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/11825870/67227480_large.webp