Is it safe to turn on my central heating with cold tank empty?

[Dsp]

The insurance cover will pay for temporary work to fix an 'emergency' issue (eg, no power, water) up to £1500. They paid for an engineer visit, resulting in the tank ballcock replacement. When fitting the new one the water was turned off at the incoming mains (under the kitchen sink) and them turned back on. As far as I know (though I wasn't watching everything) that's the only thing that was done. When the mains stopcock was turned on again, water returned to the sink but nothing came out at the loft tank. That's when limescale was blamed.

There will be a closed/failed valve in the pipe to the ball valve. Never seen limescale block a cold feed pipe
Where are you could a friendly local member help

 

[biterbit]

I am in Hertfordshire and have used two local plumbers before who I will be contacting for a permanent fix (if one is needed) but in the meantime I am going back to the insurers to question their diagnosis.

 

[Sparkgap]

I have had rust/mud/cr@p block up mains pipes in the past. In some cases the mains stopcock was turned off and when turned on again drew stuff from the mains pipe or scoured it from the inside of other pipes and blocked any narrow or tight spots. Usual blockage point was the ballvalve nozzle as it doesn't take much to block it.