There's bound to be a room in your house where Wi-Fi coverage is patchy. You can set up a spare router as a repeater to boost your Wi-Fi signal beyond the reach of your current router.

This won't work for everyone, but if you do have an old router sitting in a cupboard or drawer, you might be able to save money compared to buying the latest mesh network systems such as Google Wifi and BT Whole Home Wi-Fi.

There are a couple of different ways you can do this and if you're fortunate, you'll be able to do it without a wire between the two routers (see the slide called No wires.) If not, you will need a long network cable, or  inexpensive powerline network adaptors. Those without Wi-Fi can cost as little as £10, so it's cheaper than buying a powerline kit with built-in Wi-Fi.

Fortunately, most routers will let you set them up as a repeater and they don’t have to be the same model or even from the same manufacturer as your main router. BT's Home Hub routers can be used for this purpose - the involved process is explained here.

If the methods here don't work for you, you a kit such as the £33 BT Mini Wi-Fi 500 is an affordable way to get Wi-Fi where you currently can't.

A middle-of-the-road alternative is to buy a so-called range extender such as Netgear’s EX3700, which costs less than £30.

1. Find your router's IP address

First you need to find out some details about the router you're currently using, including which channel it is broadcasting on and what security type it is using.

On any Windows PC connected to your network, go to the Control Panel and double-click on Network or Network and Internet.  In Windows XP, right-click the network  connection that's being used to connect to your router (either Wi-Fi or Ethernet)  and choose Status, then Support, you will see a window showing how your network is set up.

For Vista, Windows 7, 8 and 10, go to the Network and Sharing Centre, choose Change adaptor settings, then right-click the appropriate connection and choose Status, then Details.

This window will show your gateway and the computer’s IP address.  Note down your gateway as this is the address of your primary router usually in the format; 192.168.1.1 or similar.

2. Connect to the router

Next open a web browser and, in the address bar, type the gateway IP address you’ve noted and hit Enter.  You should see a set up screen for your primary router.  It may ask for a user name and password.  If you know these details, enter them.  If not, the information may be on a label underneath the router, or the information may be available by searching the internet for the default user names and passwords for your router model.

Once you’ve accessed the router’s configuration screen you will see something similar to this.

3. Check your Wi-Fi settings

As you'll see there are lots of settings you can access and change, but we don’t want to reconfigure the primary router, just check its settings. Have a look at the wireless settings and find the detail which includes the router name, the channel and the security type.

This router's SSID is Belkin, is working on channel 6 and uses WEP for security (ideally you should set this to WPA or WPA2 if available, as it is here). The SSID is the name you find when searching for wireless networks from your laptop, tablet or smartphone.

Make a note of the security type because you'll try and set the slave router to the same setting. When you have finished there is usually a ‘log out’ option. You have only looked at the settings and made no changes, so there is nothing to save, if asked.

4. Reset the router to factory settings

Having unearthed that old router which you kept when you changed ISPs a few years ago, the first thing you need to do is reset this router to its factory settings. Find a small hole at the back of the router, usually marked ‘reset’.

With the router powered on, insert a paper clip or similar, and hold in for a few seconds. When you release the paper clip you should see all the lights on the router go out and come back on again.  You have reset the router to its factory settings.

5. Configure your second router

Connect this second router now, with a network cable, to a PC which is not on your network. The best way to do this is to turn off your main router for a few minutes while you set up this slave router.

If you only have one PC you will have to disconnect it from your working network temporarily. Once attached, go through Step 1 again with this router until you get to the stage where you have accessed the configuration page. Here, we're using a D-Link router.

6. Copy over the settings

Ignore any setup wizards, and go to the Wi-Fi settings page. Enable wireless, change the wireless network name to be the same as the primary router and choose a channel well away from channel 6, which is what the primary router is using. Match the security type exactly and type in the same password you use for Wi-Fi on your primary router.

7. Give it a fixed IP address

Finally you need to make the slave router work alongside the primary router by giving it a fixed IP address which the primary router will recognise and work with.

Head to the LAN setup page (or simialr) and give the router an IP address in the same range as the IP addresses given out by my main router, but outside of the range that is automatically assigned by DHCP. Dynamic Host Communications Protocol is the process by which a device issues IP addresses to equipment on the network. You need to stop the slave router giving out IP addresses to devices, leaving that task in the hands of the primary router.

Disable DHCP by un-ticking it on the relevant configuration page. To assign a fixed IP address, let's assume the main router has an address of 192.168.1.1 and that it's setup to to issue addresses - by DHCP - between 192.168.1.2 and 192.168.1.49. Give the slave router an IP address of 192.168.1.50. Remember this address as you might need it to access this router later.

On each configuration page, confirm your choices by clicking ‘save settings’ at the bottom of each page as you go. Remember, too, that once you've change the router's IP address you will have to wait for it to reboot, and then access it by typing the new IP address into your browser's address bar.

8. Connect it all together

Now we are ready to connect it all together. The ideal way to connect two routers together is with a long network cable. However, this is usually impractical so the best alternative is to use cheap powerline networking adapters.

These work by using the mains power cables in your walls and floors to act as network cables as well as passing electricity through them. They work only on ring mains which are all connected back to a single consumer unit (fuse box). If you have two separate buildings or an extension which has its own electricity supply and meter, then powerline adapters aren't going to work.

We've explained separately how to set up powerline networking adapters to get your adapters connected.

With both routers now turned on, it’s time to test your network. Take a smartphone, tablet or laptop, and check to see the signal strength when close to each of the routers. You will find that you have successfully extended the reach of your wireless network and now have a second wireless access point.

9. Or go wireless

If you’re lucky or you chose well when you bought your old router it might already have the features necessary to be reused to improve Wi-Fi coverage. Without needing network cables, or powerline adaptors, that is.

We can't list all the routers that have some sort of bridge or repeater mode, but all the usual suspects (including Apple, Belkin, Linksys, Netgear and TRENDNet) have the functionality in most of their recent products. One feature to look out for is WDS (Wireless Distribution System).

The nomenclature vendors’ use differs, but the basic steps for setting up are quite similar. In a nutshell, the key steps are finding the bridge or repeater mode in the configuration tool, choose it, and then enter whatever network information the tool asks for. That could be a MAC address, network name (SSID), spectrum band and security mode, for example.

It’s important to note that this functionality isn’t standard, so there is no guarantee routers from different vendors will work together.

10. Using custom firmware

For routers that don’t have built-in WDS (or similar) you might be able to install custom firmware such as DD-WRT, OpenWRT or Tomato. To use them takes some technical knowledge and the ability to follow instructions very closely.

For example, installing DD-WRT on a router in most cases is almost as simple as installing a program onto your computer. However, doing it incorrectly can leave you with a router that you have to throw away. So follow the instructions carefully!

Your router has to be compatible with DD-WRT, OpenWRT or Tomato and you'll have to search online for your specific router model to find out if a custom firmware can be installed. Once compatibility has been established, there is plenty of information, including precautions, for each manufacturer and router on how to install the firmware.

Once that’s done, turning on the repeater function is fairly straightforward. You will find more information on the DD-WRT website.