Short answer
First establish whether the problem is in one home or in all homes. In one home it is the indoor station or the branch to it. In all homes it is the power supply, the control unit or the door entry panel. If the door does not open while the bell does work, it is the door release or its transformer.
Who this article is for For residents and building managers. You can do steps 1 and 2 yourself, the rest is work for an electrician.
Step 1: in how many homes is it not working
This is the most important question, and it saves half the searching.
In one home. Then it is in the indoor station or in the branch to that home. After all, the rest of the installation works.
In all homes. Then it is central: the power supply, the control unit or the door entry panel.
In some of them. Often one floor or one branch of the cabling. Then there is a branch or a distributor somewhere that is failing.
Step 2: what exactly is not working
- no bell in the home, but the panel does light up
- bell works, no speech
- speech works, no picture
- everything works, but the door does not open
That last one almost always points to the door release or its transformer, not the intercom. See electric door release.
Step 3: the known causes
Moisture in the door entry panel. The most common cause with an outdoor installation. Hardened seals let rain in and then the contacts corrode.
The power supply. A transformer or power supply at the end of its life. Typical: it works but weakly, or it drops out when several things happen at once.
An indoor station that has been pulled loose. During a move or while painting.
A damaged core. Especially in older buildings where the cable runs through a damp shaft.
Step 4: what I do
I measure at the control unit whether there is voltage and whether the signal goes into the branch. Then I measure in the home whether it arrives there. That way I halve the route each time and I am usually at the location of the fault within an hour.
With an old installation whose parts are no longer available, a repair is sometimes possible with a second-hand part, but then I also discuss straight away what replacement would cost. See replacing an old intercom.
Prevention
An outdoor door entry panel should be checked once a year: seals, cable entry, buttons and whether the panel is still fixed firmly. That is a quarter of an hour's work and prevents most faults. For owners' associations (VvE) I include that in a maintenance agreement.
This prevents most of the faults that otherwise trickle in one resident at a time.
From my own work
In a block in Geleen residents complained that they could hardly understand the intercom. At the door entry panel there turned out to be rainwater behind the loudspeaker, because the rubber seal had hardened. New seal, panel cleaned and that was the end of it. There was nothing wrong with the installation itself.
When to call an electrician
- The intercom no longer works for anyone in the block
- The door entry panel is wet, damaged or vandalised
- The door no longer opens even though the bell works
For a block without a working bell or door release I come with priority. Call +31 43 204 18 26 or outside office hours use the fault service.
Frequently asked questions
It does not work for me but it does for the neighbours, where is the problem?
Then it is in your indoor station or in the branch to it, because the rest of the installation works.
The bell rings but the door does not open, how can that be?
Then it is usually the door release or its transformer, not the intercom.
How often does a door entry panel need maintenance?
A quarter of an hour once a year: seals, cable entry, buttons and fixing. That prevents most faults.
Further reading
Doorbell transformer: what it is for and why your doorbell is not working
If your doorbell is not working, it is usually the push button and not the transformer. Search in this order and you will usually have it within a quarter of an hour.
Intercom in a block of flats: how it is put together
In a block of flats the work is in the riser cable and the door entry panel, not in the handsets. That decides whether replacement turns out easier or harder than expected.
Replacing a doorbell or chime: what to look out for
Check the voltage of your transformer before you buy a chime, and where you will hear it. Those are the two things that go wrong.
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