Which SIM does the Wafer GSM-HOUSE take?
A standard size SIM (2FF), voice-capable, PIN lock removed. The GSM-HOUSE is the budget end of the market — a 2G intercom with a 200-number whitelist and battery backup — and it's fussier than premium kit about SIM basics, so get them right: active SIM, credit present, SMS centre number stored.
Which network?
2G hardware, so it needs live 2G at the door. With budget units on fading networks, the multi-network SIM argument is strongest of all: every remaining compatible network available to it, automatic re-registration, no revisit when one operator switches off.
Fitting the SIM
For the installing engineer, power off (and disconnect the backup battery so it's genuinely off):
- Fit the standard SIM in the board holder.
- Antenna connected before power.
- Reconnect battery, then mains.
First power-up
Let it register, program the whitelist and call numbers by SMS per the manual — international format for every number — and test call-in and dial-to-open both.
If it won't connect
- No registration: 2G at the door? Old-phone test.
- Commands ignored: SMS centre number on the SIM; exact syntax — budget firmware forgives nothing.
- Random reboots: power supply and battery health before blaming the board.
FAQ
How many users? 200 whitelist numbers.
What's the battery for? Riding out mains cuts — the intercom keeps working on backup.
Long-term outlook? 2G-limited. Serviceable where 2G holds; budget 4G units are the natural replacement.
Keep your Wafer GSM-HOUSE Intercom online.
LynixSIM multi-network SIMs connect to the strongest UK signal (EE, O2, Vodafone, Three) — no single-network dropouts, no contracts, built for intercoms and gate systems.
Get your SIMFull Wafer GSM-HOUSE Intercom manual
For wiring diagrams, programming syntax and full commissioning notes, download the manufacturer's manual we host.
Open the GSM-HOUSE Intercom manual page