Monthly Archives: August 2026

In this guide, we'll explain what has changed, how the replacement process works, what hardware may also require upgrading and how iACS can supply the complete range of genuine CAREL replacement controllers and accessories needed to complete the project successfully.

Thermostat wiring usually belongs to one of the following types: two-wire for basic on-off switching; three-wire that includes the common or neutral wire; and four or five-wire for multi-function thermostats used together with a programmer. Correct connection according to the wiring diagram will save you from two of the most frequent errors, which are heating system that cannot call for heat and heating system that cannot shut down.

If a motorised zone valve will not open or close, the fault is almost always either the actuator or the valve body itself, and a simple manual override test will usually tell you which. Working through voltage checks and the fault table below resolves the majority of zone valve faults without an unnecessary system drain down.

If there is any failure in the Vent Axia extractor fan, then the possible problems may include a power cut-off, tripped overload, impeller jamming, or wrong settings on the humidistat or timer. With the help of these four checks, one can solve most of the problems of the Vent Axia fan.