ATAG Short Cycling

Furnace cycles on and off frequently without maintaining steady temperature

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Oversized furnace for system load, Incorrect control settings, Faulty room thermostat or ATAG controller, Bypass valve set too open

Safety first: Adjust only user-accessible controls unless you are trained.

Check room thermostat placement; avoid locations near heat sources or drafts.
Review ATAG controller settings for minimum run times and temperature differentials; adjust to reduce cycling.
Ensure enough radiators or zones are open to provide adequate load.
If an automatic bypass valve is fitted, have a technician adjust it to the correct setting.

Medium 3/5