sensors/switches testing

hi
Does anybody know how to test with a multimeter the following
-dhw sensor
-dhw flow switch
-store sensor
want to be able to eliminate them from faults,
thanks

No way of testing sensors.
That is from Gledhill.

thanks for your time mate

That's ok.
You an try flexing the sensor cables near the sensor or any where where they are curved, bent, under strain.
To see if you can induce a reaction.
Flow switch if removed can be tested if the internal poaddle type.
With sensors if old it is advisable to replace all at the same time. Job done then.

excellent, cheers for your help

sorry to be a pain, just wanna get my head round these as there is a few on my round, am a newly qualified gas safe reg engineer,

-say for example on the dhw pump board u ran the tap and there was no live to the pump indicating it cud be a flow switch/board/sensor fault woud u jus change them all?

-and with the acb say you had call for heat from prog/room stat, but no live to pump/3port would u same again change board and store sensor , providing obviously that the temp was above 75C measured using a pipestat?

appreciate any advise on how to go about the fault finding really
cheers