Combi Boiler Room Thermostat Wiring

Combination boilers and connecting thermostats to them including hive and nest.

Combi boiler room thermostat wiring.

For those boilers which have a programmer or timer built in the only other device required is a room thermostat. 3 wire thermostat and programmer. Also covers volt free contacts and why mains voltage must not be connected t. Here the neutral is shown from the boiler however it could be provided via the programmer if this is more convenient.

The circulator pump for the central heating is normally an intergral part of the boiler so no additional wiring is required. The choice will depend on the boiler. The thermostat to the boiler or pass through a junction box if there s a combi boiler with no junction box the heat link will be connected directly to the boiler s control circuit you may need to test each cable to understand its function make sure you connect the correct cables to the heat link to avoid blowing a fuse 10. The boiler will have a terminal which activates the boiler when mains voltage is applied to it typically labelled sl or switched line.

This is the same switching arrangement however here a 3 wire thermostat is used which requires a neutral connection. A wireless thermostat is a digital device that can tell you the temperature of its surroundings. The boiler only operates if both the programmer and thermostat are on. A 2 wire thermostat is connected between line and the switched line terminal on the boiler.

The thermostats can keep the room within less than one degree of the preset temperature. There are two main types 2 wire and 3 wire. These boilers require a mains voltage thermostat which can have 2 or 3 wires. This guide shows you how to wire up a thermostat watch this and other related films here.