Flashing red light on control panel

Right. It's Italian and I don’t know if there are service agents in the UK. Googling "Nordelettrica NE266 fault codes" brought up loads of hits. I'll leave you to plough through.

Nordelecttronica have a contact section on their website. Why not try emailing their Technical Support team?

https://www.nordelettronica.it/en/Contatti

It’s a control panel that was used by a lot of UK MH manufacturers at one time but they seem to favour Sargent these days.

Nordelettronica don’t enjoy the best of reputations. I had their units fitted to a Trigano MH I had several years back and it randomly flashed faults which I ignored without consequence. Their user manuals are largely useless. I would try a reset (equivalent of ALT+CTRL+DEL for control panel software) and if that doesn’t work contact http://www.aandncaravanservices.co.uk/ who  will be able to advise you and probably repair/supply  a defective component if that proves to be the case.

We’re on hook up in Swift bolero motorhome woke up through night flashing red light with alarm on fresh water display we’ve got water in tank 

When my panel throws a wobbly I disconnect the leisure battery wait a while, and reconnect. Worked on most occasions,

About the nearest thing to "CTRL+ALT+DEL" you can get on a control panel without having a reset button located conveniently. 

Sometimes the EHU drops out due to someone fiddling putting their cable on, or off, the unit, or a local voltage drop, due to the local farmer using a welder in what little spare time he / she / they / etc have.

The alarm may be just saying power has been cut, and some units (generally) heating have to be restarted.

Rgds

The control panel flashes on our Hymer when the fresh water level falls below 25% because that is the lowest level recorded by the sensors in the tank.

Hymer encourage driving with 20l in the tank 'for safety reasons'. If we did, the control panel will always flash when switched on to fresh water. To stop the flashing we need to have over 35l in the 140 litre tank. If we don't have the control panel switched to fresh water, the fresh water alarm is not visible.

My water pump was iced up so would not turn. I pressed the pump button to turn it on (green) and the pump made a clunk noise and the light when back to amber turning the pump off. The red triangle and P30 error code came up.

once the pump thawed the pump ran with no error code. Therefore it’s very possible P30 is a pump fault or possibly an over current fault.