Help needed please: Uncontrollable heating will not stay turned off.

BMcCullough

I have a Siemens RWB27Si central heating control panel it has a temperature dial next to it. For the last 6 years I've been able to control the heating in my house solely with the dial and haven't had to touch the control panel. The heating stays off when the dial is at 0 and then you can turn it up to turn the heating on. However a few months ago the electricity ran out in my house before I could get to a shop that accepted my kind of key. When everything turned back on the central heating control panel had reset. My landlord/ housing association never gave in instructions or a manual for it so I googled my machine and tried to set it back to the setting it's been on for six years with the instructions of a similar model. It currently turned itself on at random times in the day and the control panel doesn't seem to realise that the heating is on as the little red on switch doesn't come on. It isn't anything to do with the on/off times on the control panel as I set them all to the exact same time and it doesn't turn on at these times. It turns on several times a day for one to ten minutes and turns right up to the hottest temperature that the heaters will go to. At one point I turned all the heaters off as it had bumped my gas bill to over £200 for Nov - Jan however all the heaters even when they were off were still getting hot.
While this was happening I had people employed by my landlord/ housing company coming and looking at my boiler as it was apparently broken. So far in the last two years ten people have come to look at it. The latest person to look at the boiler said it was going from 0-100 pressure gage everytime it turned on. As far as I'm aware, he fixed the issues with the boiler and the hot water started working properly, now if you run the taps for a while you get hot water for a few minutes.  He also confirmed that all the parts were there and then bled all the radiators and went through the heating control panel. He said that if he set it to central heating off and manual that I should be back in control of the heating, however the day after he'd come to fix the boiler the heating started playing up again. 
I have called the boiler company that make my boiler for help as well as the people that manufacture the control panel but was just sent round and round different companies. I have no idea how to make the heating stop doing this as this is the first time it's done it in six years. I don't know if the heating is broken or if the boiler is still broken and I don't know how to resolve the issue or who I need to be asking to get it fixed. It's costing a fortune in gas bills.

Thank you,

Gerry1

Probably a failed backup battery.

Flag it up as a fault with your housing association and insist that it's repaired or replaced within a reasonable time.  Escalate if necessary.  In the meantime, turn off the mains supply to the boiler when heating isn't required.

You'd be better off switching to a credit meter, switching to a competitive tariff and keeping a close eye on your usage by reading the meter each day and doing the sums.