Room thermostat
Connect a room thermostat to terminal I2 on the TIS Tronic 260U — dry contact required, 24 VAC thermostats need an SPDT relay, and the contact logic must be inverted.
Connect the room thermostat to terminal I2 as a dry contact — closed when the room is cold, open when it is up to temperature. The controller uses it to start and stop the central heating circulation pump, not the fire.
| Thermostat type | What to connect to I2 |
|---|---|
| Dry-contact / volt-free | Connect the two contacts directly to I2 |
| 24 VAC | Drive a 24 VAC SPDT relay, and take the relay's dry contacts to I2 |
| Line-voltage (120 V) | Do not connect directly — interpose a relay so I2 only ever sees a dry contact |
Wiring
Use a dry contact
Connect to terminal I2 with a dry contact — a volt-free switch, not a powered output.
Interpose a relay for 24 VAC thermostats
If you are using a 24 VAC thermostat, use a 24 VAC SPDT relay so the controller sees a clean dry contact.
Check the contact logic
The thermostat must disconnect the contacts when the room temperature is reached, and connect them when the temperature is lower than the user's setpoint.
Inverted logic breaks the control
For correct controller operation you need a thermostat that opens on satisfied and closes on demand. Many conventional heating thermostats do the opposite. Verify with a meter before commissioning.
How the controller uses it
When the room thermostat function is enabled, the circulation pump starts every time the room temperature falls below the thermostat setpoint (closed contact).
When the room reaches the thermostat setpoint (open contact), the controller does not simply stop the pump — it cycles it, to keep the room temperature even:
| Parameter | Range | Factory default | Effect |
|---|---|---|---|
| CH pump operating time | 30–250 s | 30 s | How long the pump runs during each cycle once the room is satisfied |
| CH pump pause time | 0–240 min | 1 min | Gap between cycles. Set to 0 to disable the pump entirely when satisfied |
Overheat override
If the boiler temperature exceeds the maximum boiler temperature setting, room thermostat control is switched off to protect the boiler from overheating. The pump will run regardless of what the thermostat says.
Wireless and remote options
MBtek offers the UNI Remote Control, which connects compatible TIS controllers to Brager Connect for remote monitoring, alarms and adjustments. The recommended installation scheme also shows Wi-Fi radiant thermostats, one per zone, driving zone actuators on the PEX manifold rather than the boiler directly.
NextMounting the controllerFitting the TIS Tronic 260U, including replacing an older TIS Tronic 83.
Frequently asked questions
Wiring a 120 V pump
Connect a 120 V circulator to the TIS Tronic 260U using the supplied 220 VAC relay block — controller contacts 7 and 8, pump to 3 and 5 or 4 and 6.
Mounting the controller
Fit the TIS Tronic 260U to the UNI boiler lid, including the five-step adapter plate procedure for replacing an older TIS Tronic 83 regulator.