Fifos 12kW electric boiler – "no water" fault after long period off, how to prime?

[Lunchbaron]

Hi all,

I've got an old Fifos 12kW electric boiler (made by Fifas Ltd, Perth, model XA0052/12UB) that's been switched off for a long time. Now it won't run. It seems to trip on a "no water" fault, presumably to protect itself.

Setup, as far as I can tell:

• Vented cylinder with an immersion heater, acting as the hub, I think as a thermal store
• Wood stove with a back boiler; a flue thermostat switches its pump on when it's hot
• Two sealed circuits, each with its own expansion vessel, gauge and filling loop: one for the electric boiler, one for the radiators
• Three pumps in total
• A simple on/off control in the kitchen for the electric boiler

What I've done so far:

• Fixed a leaking filling loop valve on the boiler circuit, and I'm repressurising it to about 1.3 bar (it was at 0.5)
• Opened the automatic air vent above the boiler, but nothing comes out, neither air nor water

Questions:

1. Is there a specific priming or refilling procedure for Fifos boilers after they've been drained or off for a long time?
2. I understand these use electrode-style heating. Does the water need any particular treatment or conductivity to work, and should I avoid normal inhibitors?
3. Does anyone have a manual or wiring diagram for this model?
4. Can anyone recommend an engineer in Aberdeenshire who knows Fifos or electrode boilers?

Thanks in advance. Happy to post photos.

 

[jj4091]

I presume this is the same or similar

https://www.plumbnation.co.uk/documents/fusion-comet-installation-and-technical-manual.pdf