Can this pattern of spikes be explained?

http://www.thinkbroadband.com/ping/share/6f9abaa4620...

All days look much the same - spikes every three hours after midnight, then every hour after 18:00 until midnight.

This is on a line which gives a stable 73.5 Mbps download.

Heating system causing noise and causing errors impacting latency?

I would be surprised! Central heating on from 07:00 to 09:00, and from 15:00 to 21:30. Hot water on from 19:00 to 22:00.

Is coax-to-the-cable-modem susceptible to electrical interference?

Or could there be an effect from a "Sam Knows" router?

Edited by John_Gray (Wed 24-Feb-16 19:58:37)

A lot less likely with coax, but not impossible to suffer interference.

In which case the most likely cause is a piece of software generating traffic at those intervals and this is exactly what the SamKnows box will do, so if this is interfering with gaming for example then time to drop the box (the boxes are meant to be intelligent and only test when you are not actually using the connection)

In reply to a post by John_Gray:

Or could there be an effect from a "Sam Knows" router?

That is the pattern of a SamKnows box doing its tests. If wired correctly it should not affect your internet service.