Communal heating issue

ThisIsWeird

Not worth knocking on a few neighbouring doors?
Whilst it's obviously possible for these units to completely fail, it's pretty rare.
Are you 100% certain it's mains powered? If you download the installation instructions, you should see how to unclip it from the wall. There seems to be three variations, two of which uses batteries (one wireless, and one wired), and a third mains-powered.)
I wouldn't take the engineer's say-so. 

playlister82

None of the neighbours know the answer, their heating just works normally. We have checked the instruction manual for this particular model and it is mains powered, and the engineer who came yesterday said it was. He believed that the thermostat is just faulty and needs to be replaced.

The other interesting thing is that the hot water and heating are all part of the same system, and the hot water is working fine, it's just the heating that isn't.

DullGreyGuy

A friend had a similar setup... basically big commercial boiler in the basement running a simple pipe around the block. In each flat there was a heat exchanger/ heat interface unit with a meter that measured how much heat was drawn from the system and distributed it to taps/radiators. 

From the basement the boiler could be controlled as a simple on/off, there was no way to turn off individual flats. The HUI had a fuse spur that it runs off and inevitably can develop its own faults. The costs of running the boiler was recharged to the units proportional to the meter reads. Theirs went faulty as it was recording a large draw when nothing should have been drawing 

playlister82

DullGreyGuy said:

A friend had a similar setup... basically big commercial boiler in the basement running a simple pipe around the block. In each flat there was a heat exchanger/ heat interface unit with a meter that measured how much heat was drawn from the system and distributed it to taps/radiators. 

From the basement the boiler could be controlled as a simple on/off, there was no way to turn off individual flats. The HUI had a fuse spur that it runs off and inevitably can develop its own faults. The costs of running the boiler was recharged to the units proportional to the meter reads. Theirs went faulty as it was recording a large draw when nothing should have been drawing 

Thanks, having done some further research I have identified there is no individual on/off switch for each flat, apart from the mains power and fuses that lie within the flat. So no one can come and turn the boiler off just for my mum’s flat eithout being inside the flat itself. We checked and all the mains switches in the flat are ON.

We also checked and the HIU in the flat is running correctly. So the problem must lie with the thermostat. We are going to wait for the council to come out again to replace the thermostat and hope this solves the problem.

Albermarle

playlister82 said:

None of the neighbours know the answer, their heating just works normally. We have checked the instruction manual for this particular model and it is mains powered, and the engineer who came yesterday said it was. He believed that the thermostat is just faulty and needs to be replaced.

The other interesting thing is that the hot water and heating are all part of the same system, and the hot water is working fine, it's just the heating that isn't.

I would guess that the hot water is on 24/7, or for the same fixed hours of day for everybody. So the thermostat only controls the heating. Looking at the pic you posted there does not seem to be any hot water symbols. 

ThisIsWeird

playlister82 said:

Thanks, having done some further research I have identified there is no individual on/off switch for each flat, apart from the mains power and fuses that lie within the flat. So no one can come and turn the boiler off just for my mum’s flat eithout being inside the flat itself. We checked and all the mains switches in the flat are ON.
We also checked and the HIU in the flat is running correctly. So the problem must lie with the thermostat. We are going to wait for the council to come out again to replace the thermostat and hope this solves the problem.

That does seem to narrow it down to a faulty 'stat

Please let us know how it pans out.