Heater valve

[jam]

Hi I'm new owner of a 2001 406 110 HDI estate (had a 205 a while back) I've noticed a loud annoying humming sound from under the dash and located it to the heater valve(s) on the bulkhead bosch part no 0928400309, can anyone shed some light on what it does and whether I need to replace? thanks for any help in advance

[lozz]

the only valves ican see on the bulkhead there is 3 of them in a row
do you mean them?

[lozz]

Ah ithink iknow what you mean now,
does the humming stop after say around 50 secounds ?

if so its normal mines done the same thing and others confirmed the same too its not something to worry about,
its a pre-heat related thing

[jam]

Thanks for your help

[jam]

mine only has 2?

[lozz]

mine only has 2?

same as mine then
imentioned 3 as some have 3,
the 1st one is for the turbo 2nd one controls the Egr,
there mounted on a plate theres rubbers behind the bolts holding it all to the bulk head,
the bolts go thru rubbers you will see where imean tighten them and the noise will go

the purge valves can hum sometimes thats normal but any vibration will be the plate holding them vibrating)

[jam]

Cheers for your help!