Security light not turning off

[Alison556]

We've got a separate security light/pir sensor and all of a sudden, it's not turning off.

Nothing has happened (ie bulb blowing, power cut or anything like that) that might have caused a problem - it's just decided to come on and stay on.

Is it likely that the pir has malfunctioned and needs replaced?

 

[JohnW2]

We've got a separate security light/pir sensor and all of a sudden, it's not turning off. ... Nothing has happened (ie bulb blowing, power cut or anything like that) that might have caused a problem - it's just decided to come on and stay on. ... Is it likely that the pir has malfunctioned and needs replaced?

Are you sure that it hasn't got into a 'manually on' mode, perhaps due to a very brief (fraction of a second) power cut?

If you have a switch or isolator which controls the light/PIR, try turning it off, leave it off for a short period (anything more than 10-15 seconds) and then back on. If you do that, the light may immediately come back on and stay on for it's timed period (whatever that is set to) before going off - so don't immediately assume that it hasn't worked!

If that doesn't work, you probably need a replacement PIR.

Kind Regards, John

 

[Alison556]

I'm not sure about a manually on mode I tried switching it off at the isolator, left it, switched it back on and waited - it didn't go off. I've had to just switch it off altogether just now cos it was shining right into the bedroom.

 

[JohnW2]

I'm not sure about a manually on mode I tried switching it off at the isolator, left it, switched it back on and waited - it didn't go off. I've had to just switch it off altogether just now cos it was shining right into the bedroom.

It sounds as if you probably need a new PIR then.

Many PIRs have a built in 'manually on' ('over-ride') mode. To implement that, you switch it off (with isolator or whatever) and then immediately back on (within a second or so) - and that makes the light come on permanently until you switch it off. As I said, things like very brief power cuts can emulate that rapid off-on switching and therefore put it into that mode. However, it sounds as if you have excluded that as a possible cause of the problem.

Kind Regards, John

 

[Alison556]

Thanks John. I'll check it again. I switched it off at the isolator and I've not had a chance to get a new one yet but maybe I switched it on too quick when I tried testing it, so I'll do it again and see.

Originally, it was off and I went out and it didn't switch itself off again.

 

[Alison556]

Ahh I left the security light switched off and hadn't got round to getting a new PIR but I thought I'd check it again - and lo and behold, it worked.

Now it's just malfunctioned again so I guess I'd better go and get that new PIR.

 

[JohnW2]

Ahh I left the security light switched off and hadn't got round to getting a new PIR but I thought I'd check it again - and lo and behold, it worked. ... Now it's just malfunctioned again so I guess I'd better go and get that new PIR.

Hmmm - it does sound a bit iffy, I agree

Kind Regards, John