Thanks for your replies, after a day of wifi drop outs i’ve been reading again about what to go for but all i get on the various review sites are the same product descriptions written by marketing people and they don’t give much technical detail that i can work with.
May be someone on here can give me some worthwhile advice.
My house is L shaped and large because it also has a granny annex, wifi is a problem because all internal walls are solid 9" brick including the upstairs and in the lofts.
I have attached a house layout and network diagram. Reception at each end of the house is sketchy or non existent if the wind’s in the wrong direction. Both PC’s are used for gaming so currently have hard wired LAN from the TP-link network.
My plan was to use a MESH system with the existing LAN cables (nightmare to move) for backhaul and connecting the PC’s, if the units only have 2 Ethernet ports i would add a switch or splitter where needed. I need at least 3 network devices, possibly 4.
I now have a Drayton Wiser multi-zone heating kit which will need to run from the WIFI network and it would be useful if it integrated with whatever Smart home system i use - I still prefer Smartthings and i now have two V3 hubs bought second hand but i will sell one.
I was attracted to Smartthings WIFI because it also has Z wave and Zigbee and the wired backhaul, i also have several Samsung devices including a tablet.
So any suggestions on a MESH wifi system? Ideally below £200 but i could go as high as £300 if it’s really necessary.
The final point, if i did want Smartthings wifi where can i buy it? All i seem to find are the hubs, on Amazon a single wifi unit is £230 ! What’s the RRP?
Thanks for any help offered.

