Connecting one light to two PIR detectors?

[Dr Mike Oxgreen]

I am pondering fitting a light to illuminate down one side of the house, and would like to use a dusk-to-dawn PIR detector. As far as possible I'd like the PIR detector to cover the whole side of the house, so that the light comes on when you approach from either end.

The problem is that half way along this side of the house is the boiler flue, which sends its exhaust out just above head height. Obviously this will cause a PIR detector to trigger erroneously.

Is it possible to power one light from two PIR detectors? I could mount a PIR detector on each side of the flue, pointing away from it, and this would cover most of the area I want. Would drifting gases still cause a problem?

Can I wire the light in parallel to the outputs of both PIRs, so that it would light up in response to either PIR?

The only problem I can think of is that when just one PIR triggers, the switched output on the other PIR would become live. Would this cause that PIR to malfunction in any way?

[Dr Mike Oxgreen]

Brilliant - thanks folks! I couldn't think of any reason why not, but it does no harm to ask.

[Dr Mike Oxgreen]

Superb diagram, thanks!

So I just need a length of four-core cable between the PIRs to link the lives, neutrals, earths and switched lives together, then wire my light into one of the PIRs in the normal way. It's obvious when you think about it!

I can see myself needing to glue a piece of opaque plastic to one side of each PIR to act as a "blinker" to stop it seeing any drifting flue gases, but apart from that I think it sounds simple enough.

Thanks for all the help!