Most probably or an earthing issue as James said, when we do big sites all cameras are 24ac and DVR in main building and lodge one have to be fed from same phase.
Buy one of these http://www.ebay.co.uk/itm/Diy-BT-10-Metre-Telephone-Phone-Extension-Lead-Cable-Socket-Adaptor-Kit-10M-/300931853492?pt=UK_Phones_PhoneLeads_RL&hash=item4610efacb4
and paysomebody to fit it
Get Virgin to re-instate it as before at their cost as they should have asked you about it.
Or get a local telephone engineer out of the paper that fits extensions.
put bell delay to 0 link bell output to link A set link A as timer (for your bell delay) set link A destination (latch or reflex timer) to another output for your bell.
You would need to play around with the modifier for link timer to get it to do what you want.
But if you have a Gal with 5 groups, then setting up links should be easy.
When there is no power on the loop the loop isolaters don't operate, i dont know gent that well have the devices you are using go isolated bases ? is one wired wrong ?
If you have it on a bench and the loop is made up of a couple of meters of cable, the loop may be to short and resistance of the loop is not enough for the panel.
Soz, re read your post, your hardwiring back to a wireless contact, cant see why the float switch wouldn't work then as long as it gets enough water to tip it over and float.
That float detector will need a certain amount of water before it sits up and triggers which could be 10 -20 cm deep
you need something thats detects water by resistance
http://www.jablotron.com/en/product-catalogue-1/alarms/wired-devices/detectors/environmental/ld-12.aspx
or posh one
http://www.fibaro.com/uk/the-fibaro-system/flood-sensor