What could be causing none of my radiators to work during bathroom work?

[BoilerBother]

Having bathrooms done. Fitter has been draining house of water etc. Suddenly none of the radiators are working and the boiler isn't firing up. Fitter said it won't be with anything they've done and need to get a gas engineer out. Any ideas? TIA

They’ve depressurised the system ?

It sounds like it isn't a coincidence. Maybe ask @pigletjohn

I agree that I don't believe it's a coincidence but unfortunately the fitter is adamant it's nothing to do with them and I have no way of proving this. Not sure what depressurising means, but if it means bleeding air out of the radiators that doesn't do anything either.

You could also check that they haven't turned the power switch off (a separate power point, not one on the boiler itself)

But it sounds like there's no water in the boiler, which means it will have no pressure. Do you know how to let water back into the boiler? Ours has a key that you attach to a nut underneath the boiler, which opens up a pipe to re-fill it with water. There are loads of YouTube videos showing you how to do this, depending on the make of your boiler.

Check the pressure gauge on the boiler - that will tell you if it's depressurised. Ours needs to be set with the needle between 1 and 2 to function properly.

<disclaimer: I am not a plumber!>

Do you know what type of boiler you have? If its a combi boiler, has the hot water from the taps stopped as well? are the lights on the boiler and programmer/stats on? is the control panel showing a fault code? usually a number were the water temp is displayed, as mentioned, check the water pressure on the boiler, its usually a gauge on the boiler along with the other controls, has the needle dropped to the red zone? frankly it sounds too much of a coincidence not to be caused by something they've done, i.e. cut the mains water off, drained the heating by mistake, or cut off the electrical supply. if worst comes to worst inform them that if you get a gas engineer out and its down to them you will be deducting it from their bill, that may focus their minds on getting to the bottom of it.

Meant to add, if they have drained a towel rail in the bathroom that would definitely be a cause.

Sounds like water pressure,if too low the boiler won't work to stop it being damaged

what have they drained? The bathroom towel rail or radiator that works on the central heating? The hot water cyclinder? Both of those will stop the boiler working.
I would be concerned that the fitter thinks he hasn’t caused the problem. He may not be qualified to correct it but an experienced qualified plumber will know how central heating systems work even if they are not gas safe registered.

It does sound as if he hasn't filled the system back up again. Either find your instruction manual for your boiler/ google/ or find a you tube video. It is usually a little valve on the boiler next to the pressure gauge and you just pull it. Has the fitter turned the water off at the mains and not switched it on again?