S1255

NIBE S1255 is an inverter-driven ground-source heat pump with an integrated domestic hot-water cylinder. NIBE includes S1255 in its published UK Pro warranty terms, but it is absent from the current UK ground-source category, which lists S1256, S1156, S1155, F1345 and F1355.

Availability

NIBE introduced S1256 as the integrated-cylinder sister model to S1156. That provides a newer current product context, but it does not prove the supply status of every S1255 variant or distributor unit. S1255 is therefore marked as having unconfirmed current UK new supply rather than being described categorically as discontinued.

Current UK supply status depends on the complete S1255 code, manufacturer-backed supply confirmation and the applicable warranty documents. For an installed unit, the serial number and matching manual are more useful than the present catalogue.

Product arrangement

S1255 combines an indoor inverter-driven brine-to-water heat pump, controls and domestic hot-water storage in one tall cabinet. It still needs a correctly designed ground or water-source circuit, heating distribution, electrical supply and all installation-specific hydraulic and safety components.

Output range, electrical arrangement, cylinder details and performance differ across S1255 variants and document editions. They should be taken from the exact data plate and matching technical manual, not assumed from another model carrying the same family name.

The S-Series controls can connect to myUplink for monitoring and adjustment. Recorded temperatures and compressor operation may help diagnose an existing system, but they do not by themselves verify the ground-array sizing or heat-loss calculation.

Existing-system condition

Retain the model and serial number, commissioning report, ground-loop design, antifreeze and pressure records, electrical details and control settings. Cylinder condition, hot-water temperatures, immersion or supplementary-heater operation and water quality should be included in servicing.

For replacement work, cabinet size is only one compatibility point. Source-loop capacity, flow and pressure loss, design output, emitters, electrical supply and control changes all affect compatibility. A current S1256 is not automatically a direct replacement for every S1255 installation.

Any warranty follows the terms registered for that unit. Current warranty summaries should not be applied retrospectively.

Related entries

• NIBE
• NIBE S1256
• NIBE S1155
• Ground source heat pumps