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Upgrades · Article 2026

Is your Fermax intercom very old with no spare parts? Here's what you can do

📅 June 2026 ✍️ Fermax Technical Service Valencia ⏱ 8 min read

The door phone has been on the wall for decades, it's started playing up, and when you go looking for the spare part you discover the model has been discontinued. Don't worry: the original part no longer existing doesn't mean going without an intercom. Here are all the realistic options, from the cheapest to a full system upgrade.

Why door entry systems get discontinued

A well-installed door entry system lasts a remarkably long time: in Valencia we still come across Fermax equipment from the 80s and 90s working every day. The trouble starts when something breaks, because no manufacturer can keep every model in production forever. The reasons are the usual ones:

  • Technology moving on: multi-wire analogue systems (4+N) have given way to digital systems like VDS and DUOX Plus, which run on just two wires and offer far more features.
  • Components no longer manufactured: circuit boards, buzzers and plastics from 30 years ago depend on suppliers and moulds that no longer exist.
  • New regulations and standards: today's equipment meets accessibility, efficiency and compatibility requirements the old units never had to consider.
  • Catalogue cycles: each product generation replaces the previous one; after a reasonable period, the manufacturer stops producing spares for the old model.
💡 Key fact: your model being discontinued doesn't mean there's no solution. Fermax keeps compatible replacements for many of its older models, and for the rest there are universal handsets or a full upgrade reusing the existing wiring.

How to find out if your model has a spare or compatible replacement

Before giving anything up for lost, you need to identify exactly which unit you have. It's easier than it sounds:

  • Look for the handset reference number: it's usually on a sticker on the base, on the side or inside the casing (for example, the classic 2040, 8039 or TELEF series).
  • Check the number of wires reaching the handset: four or more suggests an analogue 4+N system; two wires point to a digital VDS or DUOX system.
  • Take a look at the street panel: the design, model and year say a lot about which generation the system belongs to.
  • Take a photo of the unit inside and out: with that, a technician can identify the model in minutes.

The good news is that Fermax is one of the manufacturers that best looks after continuity: for many old handsets and monitors there's a current official replacement that connects to the same installation with minimal changes. Knowing which generation you have is half the job; if you want to place your equipment, this guide explains how to identify whether your Fermax system is 4+N, VDS or DUOX.

Technician's tip: don't buy a "compatible" handset online before identifying the system. Every week we get call-outs for newly bought units that don't work because the installation is VDS or DUOX and the handset purchased is analogue. A photo by WhatsApp before buying saves you money and headaches.

Your options when there's no spare part, from smallest to biggest fix

When the original spare no longer exists, there are four possible routes. Which one makes sense depends on your system, on whether the fault affects just your flat or the whole building, and on how much you want to invest:

OptionWhen it makes sense
Compatible universal handset4+N systems with a fault in your flat only
Official Fermax replacementWhen a current equivalent of the model exists
Replace your terminal onlyShared installation in good condition
Full upgrade to DUOX PlusVery old system or recurring breakdowns

The first two options fix the immediate fault with minimal outlay. A full upgrade to DUOX Plus has one huge advantage in older buildings: it runs on two non-polarised wires and normally reuses the existing wiring, so the panel and terminals are replaced without chasing walls or building work. It also opens the door to monitors with video and even answering from your phone: we explain it all in our guide on replacing an old intercom with a video intercom.

Signs it's time to upgrade instead of patching things up

Repairing is always valid as long as it pays off. But there comes a point where every fix is money sunk into a worn-out system. These are the signs we see every day in Valencia's residential communities:

🔁 Recurring breakdowns
If every few months a different handset, the call or the door release fails, the wear is now general: wiring, panel and terminals are all ageing at once.
🔍 Spares harder and harder to find
When spare parts can only be found second-hand or at outrageous prices, every repair gets more expensive and takes longer.
📉 Repairs that no longer pay off
If the cost of the next repair approaches the price of a new terminal — or the past year's total approaches the cost of upgrading — the maths is clear.
⬆️ The building is asking for more
Accessibility, video entry, door release from the phone: if the neighbours are already talking about these features, it's better to channel the spend into an upgrade.

In these cases, our honest recommendation is usually to quote both routes — one-off repair and full upgrade — at a fixed price, so you or your community can decide with the numbers on the table.

Frequently asked questions

How do I know if my old Fermax door phone has a spare part or replacement?

Look for the reference number on the casing or on the sticker inside the handset and ask us: Fermax keeps compatible replacements for many of its old models, even though the original is no longer made. If you send us a photo of the unit by WhatsApp, we can usually tell you the same day whether a direct replacement exists and what the swap would cost.

Can I fit a universal handset on my old Fermax intercom?

On analogue 4+N installations it's usually possible to fit a compatible universal handset as long as the wiring scheme is respected, and it's the cheapest option when no official replacement exists. On digital systems (VDS, DUOX) not just any terminal will do: you need equipment compatible with that protocol, which is why it's worth having a technician assess it before buying anything.

Does the wiring need replacing to upgrade the system with DUOX Plus?

In most cases, no. DUOX Plus runs on two non-polarised wires and usually reuses the building's existing wiring, even in old 4+N installations. That means the whole system (panel and terminals) can be renewed without chasing walls or building work, which is exactly what makes this kind of job expensive.

Is it worth keeping on repairing a very old intercom, or better to upgrade it?

If breakdowns keep recurring, spares are scarce and the installation is several decades old, every repair is money invested in a system that will keep failing. In those cases upgrading usually pays off: the cost is shared between the neighbours and the building gains reliability, kerb appeal and new features such as video entry or door release from your phone. You'll find guide ranges in our article on door entry system prices in Valencia.

Has your Fermax intercom run out of spare parts?

We identify your model, tell you whether a replacement exists and quote every option at a fixed price. Valencia city and province.

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