Flame detectors generating multiple nuisance alarms randomly

Dear Sirs,

We are currently experiencing an issue with our Flame detectors (THOR S241f+). These detectors are generating multiple nuisance alarms randomly.

I would be pleased if someone could help me to identify the root cause and suggest some solution that can help me.

Kind regards,
THOR S241f+ evidently usinf optical sensing.
They tyically have problems if not properly installed.
The OP will have to sketch out his installation.