Ask whether powerline adapters work and you will hear both answers, both from people telling the truth. In one house they carry the broadband upstairs as well as a cable would; in the next they are slow or drop out. The adapters are not the difference. The house is.
How powerline works
One adapter plugs into a wall socket beside your router and connects to it with a network cable. A second plugs into a socket in the room that needs the connection. The two send your data to each other along the electrical wiring already in the walls, so nothing is chased into plaster and no floors come up. Irish sockets take the same three-pin plug as the UK, so adapters sold for either fit.
The pair link with a button on each adapter, and newer models encrypt what passes between them, so a neighbour on the same supply cannot read it.
The speed on the box
Powerline adapters are sold by a headline figure, such as 600, 1000 or 2000. That is the fastest the link between the two adapters can run in ideal conditions, not the speed you will get. NETGEAR's own guidance is that real speeds differ significantly, because of the wiring, the overheads of the connection and electrical noise on the line. Treat the number as a ceiling, and the speed in your house as something to measure.
What decides it in your house
| What | Why it matters |
|---|---|
| Extension leads and surge protectors | They filter out the signal the adapters use. NETGEAR and TP-Link both say to plug straight into the wall. |
| Appliances | Every appliance on the wiring adds electrical noise. TP-Link names washing machines, dryers, fridges and air conditioners, and advises keeping adapters as far from them as you can. |
| The route between the sockets | Powerline works across the breakers in your fuse board, but the signal travels the whole route between the two sockets, through the board and along each cable, and loses strength on the way. |
| The wiring itself | Its age and layout. The same adapters can do well in one house and poorly in the next. |
If speeds drop at certain times, switch high-power appliances off one at a time, as TP-Link suggests, to find the one making the noise.
Setting it up properly
- Plug each adapter directly into a wall socket, never into an extension lead, adapter or surge protector.
- Choose sockets away from the washing machine, the fridge and the tumble dryer where you can.
- Pair the adapters, then test speed at the far end before you decide where they live for good.
Wi-Fi at the far end
Some adapters have Wi-Fi built in, which makes a second network in that room. The other way is to plug an access point, or a mesh unit, into the far adapter, so the powerline link feeds a proper Wi-Fi signal on the floor that needs it, under the same network name as the rest of the house. That is the fix we fit, and our guide to mesh Wi-Fi explains why a wired or powerline link between units beats one over the air.
Measure it in your own house
Because the wiring decides the result, the only way to know is to test powerline in your own house. Run the free Wi-Fi check beside the router and in the room that struggles first, so you know what you are starting from. Our guide to extenders, mesh and powerline covers which problem each one fixes.
The €395 home network assessment does the measuring for you: your broadband tested by cable at the router, every floor measured, and a working powerline and access point trial left on the floor that struggles for three days, with the figures in writing. It is credited in full against any work you go ahead with.