How does Alva Link actually connect to my heat pump?

It depends on your brand and model. The Alva app walks you through it during setup — you select your heat pump brand and model, and the app tells you exactly which connection method to use and how to set it up. Here's a simplified overview:

Modbus TCP/IP (Ethernet cable): For brands like NIBE S-Series, Daikin (via HomeHub), Alpha Innotec, and Stiebel Eltron (via ISG Web). You connect an Ethernet cable from Alva Link to the heat pump or its gateway. This is the deepest integration — Alva can read every sensor and control every setpoint.

Modbus RTU (RS-485 serial cable): For brands like NIBE F-Series, Daikin, Mitsubishi, and Panasonic (via gateway adapter). A two-wire serial connection. Same depth of control as Ethernet, just a different cable type.

OpenTherm (two-wire thermostat bus): For brands like Vaillant, Weheat, ATAG, Baxi, and some Daikin and Bosch models. Alva Link replaces or intercepts the thermostat connection, giving proportional water temperature control. This is built into the Alva Link hardware at a component cost of about €1–2 — no external adapter needed.

SG-Ready (relay contacts): The universal standard. Two dry contacts from Alva Link connect to the SG-Ready terminals on your heat pump, giving four operating modes: blocked, normal, encouraged, and forced. Over 500 models from all major brands are BWP-certified for SG-Ready. If your heat pump was manufactured in the last decade, it almost certainly supports this.

Outdoor sensor spoofing (analog wire): The ultimate fallback. Alva Link sends an analog signal that mimics an outdoor temperature sensor. By making the heat pump "think" it's colder or warmer outside than it actually is, Alva can indirectly steer heating behaviour. It's less precise than digital control, but it works on virtually any heat pump.

No electrician is required for most connections. The Alva app guides you step by step.

It is still not decided which support will be shipped first, as we base this on number of purchases. But we will work as hard as we can to get the most control possible for your specific heat pump.