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How to install a video door intercom

Updated: 16 October 2026

The kit is open, the old handset is off the wall, and the cable in the hole may not match the station you bought. How to install a video door intercom, for the kits in this set, means a picture on the indoor screen, then a stop before the consumer unit. You can reuse a sound pair or four cores when the new station is built for that count. You should not invent a colour code the listing never printed. What each listing is for sits in the [video door intercom comparison](/hub/burglar-protection/video-door-intercom). The Products Compared editorial team used the UK listings and public guidance on 15 October 2026. A qualifying purchase can earn a commission at no extra cost to you.

The kit is open, the old handset is off the wall, and the cable in the hole may not match the station you bought.

Our top picks

EZVIZ EZVIZ CP5 7 inch Wi-Fi video door phone

Best overall

EZVIZ EZVIZ CP5 7 inch Wi-Fi video door phone
8.9/10about £161.49
View offer
TMEZON TMEZON 7 inch wired video intercom

Preis-Tipp

TMEZON TMEZON 7 inch wired video intercom
7.6/10about £79.99
View offer
TKMARS TKMARS 4.3 inch no-Wi-Fi video doorbell

Alternative

TKMARS TKMARS 4.3 inch no-Wi-Fi video doorbell
7.3/10about £58.99
View offer
On this page
  1. 1.Match the kit to the cable you can see
  2. 2.Pair or terminate, then test before you drill
  3. 3.Fix the outdoor unit where the radio can hear it
  4. 4.Where you stop

Match the kit to the cable you can see

Count intact cores before you strip anything. Two continuous conductors are the EZVIZ CP5 case. Four intact cores are the TMEZON bus and the QingTianTongYun V168M4. Both expect you to supply the long cable. The TMEZON box has a short test lead and a 4-pin connector, not the hall run. No copper means a radio kit. If the count does not match the box, change the kit. A 4-wire station on a confirmed pair will not produce a picture. The purchase choice between 2-wire and 4-wire stays on wired or wireless video door phone.

Pair or terminate, then test before you drill

A Winnes K18S is described as factory-paired. Prove the call while both pieces are still in your hands. The TKMARS listing tells you to test the link before you fix the outdoor unit. On the EZVIZ, connect the two conductors as the paper in your box shows, and only then mount. If that paper is missing, do not borrow another brand’s colour chart. The CP5 parts field reads 36 EU, which is not a UK wiring key. For a TMEZON, use the 1 metre test cable first. A blank screen on that short lead is the kit or the connector, not the wall. Optional 12–24 V on an ACEBELL or XPJ is a low-voltage feed, not a new circuit. An ACEBELL review describes a missing hard-wire connector, so do not start that feed until the plug is there.
EZVIZ EZVIZ CP5 7 inch Wi-Fi video door phone

Testsieger

EZVIZ EZVIZ CP5 7 inch Wi-Fi video door phone
8.9/10about £161.49
View offer

Fix the outdoor unit where the radio can hear it

Fix the outdoor unit where the test succeeded. ACEBELL and XPJ both say not to mount on a metal door. Metal detunes the radio, so a call that worked on the kitchen table can die on a steel leaf. Move the unit to the frame or the masonry and test again. Screw a wired station into a sound frame, with a drip loop so water does not run into the connector. The TKMARS indoor range is 5 to 10 metres, against 50 metres in the open. Aim at the caller and the mat. A 160° or 170° view of the pavement is a data-protection problem, and the ICO expects you to capture less once the picture leaves your boundary.

Where you stop

You may finish a plug-in monitor, a pre-paired radio test, and a low-voltage pair the kit is built to reuse. Stop for new 230 V work. In England, Approved Document P and BS 7671 treat a new circuit in a dwelling as notifiable. A plug-in adapter or an extra-low-voltage pair is not that job. Scotland, Wales and Northern Ireland are not covered by that English document. Call an electrician for new mains work, a transformer you cannot identify, or a fire-door strike. Call an installer for a communal entrance or a shop door. A screen that must work with no account can stay with video door phone no Wi-Fi.

Common questions

Can I reuse the old door-phone cable?
Yes, when the intact core count matches the kit. Two continuous conductors are the EZVIZ CP5 case, ideally a twisted pair. Four intact cores are the TMEZON and V168M4 case, and you still supply the long cable. The TMEZON box includes only a short test lead. A cut core is not a reuse.
What if there is no wiring diagram in the listing?
Use only the paper in the box. A UK review of the EZVIZ CP5 says the listing had no diagram, and a parts field that reads 36 EU is not a substitute. If the box paper is missing too, return the kit rather than guessing the terminals.
Why does the picture die on a metal door?
The outdoor radio is against a steel sheet, which detunes it. ACEBELL and XPJ both warn against a metal door. A unit that called the monitor on a wooden table can show nothing on that leaf. Move it to the frame beside the door and test again. A wired 4-core run does not use that radio path.
The 4-wire kit has only a short test lead. What do I buy?
Buy 4-core cable long enough for your run, and use the connector supplied with the TMEZON. Prove the picture on the 1 metre lead first. The V168M4 states a maximum of 100 metres, which is a listing limit, not a measurement through your walls. The strike is still a separate part. Look in the V168M4 box before you trust the power-supply line.
How do I know the camera is filming the street?
Stand on the pavement, or have someone stand there, and watch the indoor screen. If their shoulders, the neighbour’s path or the road fill the frame, the lens is too wide. The ICO treats a doorbell that films beyond your boundary as home CCTV. Move the station until the mat and the caller dominate.
When do I stop and call someone?
Stop for a new mains circuit, a transformer you cannot identify, a fire door that must keep its closer, a communal entrance, or a shop door. An electrician takes the 230 V doubt and the fire-door strike. An installer takes the shared entrance. You can continue with a tested low-voltage pair, a plug-in screen, or a pre-paired radio unit.

Related pages

Buying guide

Video door intercoms

Best video door intercom for the cable already there

Video door phone no Wi-Fi: the monitor is the handset

Wired or wireless video door phone: follow the cable

Sources

Public UK sources and the amazon.co.uk listings in this comparison. Listings read on 15 October 2026.

  1. ICO: home CCTV systems (retrieved 15 October 2026)
  2. GOV.UK: domestic CCTV, including video doorbells (retrieved 15 October 2026)
  3. GOV.UK: Approved Document P, electrical safety in dwellings (retrieved 15 October 2026)
  4. IET: Part P frequently asked questions (retrieved 15 October 2026)
  5. Ofcom: short-range devices (retrieved 15 October 2026)
  6. Business Companion: mixed contracts and the Consumer Rights Act 2015 (retrieved 15 October 2026)
  7. Which?: how to buy a smart video doorbell (retrieved 15 October 2026)
  8. EZVIZ: CP5 product page (retrieved 15 October 2026)