I remember reading about a similar issue on here a while back and it turned out to be the neighbours faulty flourescent garage light putting out interference.

Easiest way to to rule out your property is to switch off everything at the fuse board/consumer unit.

In reply to a post by Zarjaz:

Easiest way to to rule out your property is to switch off everything at the fuse board/consumer unit.

They might find it difficult to get their modem to sync to test if this made any difference

Have you spoken with neighbours, both immediate and say 3 doors away in both directions?

Do they have problems with their connection or not?

If those immediately next door do,maybe just one side do have, but no one else, the problem could be in one of te two properties. IF neighbours several doors away are also seeing it ten the problem could be outside the properties and an external source.

Can you keep an accurate log of when it start and ends?

I helped resolve one problem where it was a radio station that only broadcast for a few hours every evening - their location was 20 miles away however they used a directional transmitter very close to where te problem was being seen.

Fair point ..... had forgotten I have a HHT which needs no juice to sync

Should be possible to rig up a 12V battery to the ONT power input - even for those which didn't come with their own BBU.

NOTE: Talking about a FTTC service here not FTTP.

Are you having problems every night, or just some?

The reason for asking is that Amateur radio operators have contests in the evenings, but not every evening. I used to see issues similar to what you are describing when there were 80m contests on.

The FTTC issues are not every night. Maybe happens (at least me noticing it) maybe once / twice per week - however i'll try and keep a log.

WiFi interference seems more common daily (i.e. it's acting up. but the power levels remain fine). The issues with the Evohome having unsuccessful communication if message are pushed out all at the same time (i.e. shut system down) is present all of the time. The comms issues from the zigbee also seem to be very common if the device is moved more than a couple of meters from the exterior wall where the meters are located.

Appreciate there could be multiple sources here as power levels are fine most of the time whereas wifi is intermittent.

For reference my house is a conventional build (brick and tiles). Exterior brick with blockwork being concrete, internal garage (conversion) is thermalite. The internal walls are mainly 15mm plasterboard walls. Most of ceilings between ground and first floor do have resilient bars in (a thin metal bar that holds the soundboard plasterboard up. 30mm living room, 15mm all other rooms. All plasterboard walls are filled with rock wool too of between 50mm to 140mm thickness.

Hmmmmmm .... reading your last post, I’m doubting REIN now. And if it is, you’ll be very lucky to locate it.