Cleaner has cost me over £1,000 on energy bill?

If the property was empty you should have instructed your agents to do weekly inspections as per the terms in most people's buildings insurance and report back.

At least you didn't have burst pipes.

Sorry I can't offer any solution for you.
However, I had multiple lights left on for a fortnight recently in an empty property we are selling, so regret not accompanying the agent who failed to switch them off, as I am local to it. Only a very minor thing, but irritating, and a total waste of the planet's resources day and night.
I increasingly think if you have time, control what you can and do some of the boring stuff yourself, as it's hard to let yourself down. Not easy though when your property is beyond a reasonably local distance.
Personally, until and if we reach a point where there are too many properties to cope, I will avoid agents by chasing arrears immediately and using a few really trusted contractors directly with specific instructions such as " ensure you have a fire extinguisher with you without fail when using naked flame soldering copper, especially near wood".
It's not difficult either to monitor landlord regulation by keeping your eye on the ball.

I agree that the property should have been inspected as it was left empty, but what exactly was the 'managing agent' managing if the property was empty with no tenant in there? Did you arrange for them to do inspections and pay them for their time?
Also, to hear that the tenancy ended in early December and they only managed to get a cleaner in there on the 2nd January is also a concern. I feel it may have been beneficial to deduct an allowance for the cleaner that you then arranged after you had finished your refurb, but that's not the issue in question.
If your electricity bill started to peak in late December then perhaps the cleaner went in over the Christmas period if they had the free time rather than leave it until the 2nd Jan - presumably they would have had to get a key from the agent and the agents would have a record of when this was logged out and returned.
I think you may have a hard job proving any of this - other possibilities are that the previous tenants had an app that they could regulate the temperature from their phones (but that is only assuming the heaters were left switched on at the mains) and they had no real need to.....Good luck

Reply to the comment left by Nikki Palmer at 31/01/2023 - 11:31
If you have a smart meter, it can tell you which day and at what time the energy was used.

If the property has smart meters then the data from those would be invaluable. You'd see the exact date and time that this sudden surge in energy usage started. If the cleaner denied being there at that time then would it be safe to assume there would be a record of a small amount of energy usage for the period for when the cleaner was supposed to be there? Vacuuming, hot water etc?

Either way, the cleaner was appointed by the letting agent so it feels to me like the responsibility therefore lies with the letting agent.

Presumably the cleaner has invoiced the agent for the work so there should be an invoice that the agent can show you giving the date the property was cleaned.
Also if the heating was on so high why was this not reported to the agent by the cleaner. Surely this is something that the cleaner would have noticed.
Check the dates when the electricity went high and make sure it was not you who left it on by accident.

It's not clear what you could actually prove here so you're on a hinding to nothing unless someone admist fault.

In the ideal world (that doesn't exist), you or the agent would have been making regular inspection visits to the property to check on things.

Another good reason not to use/trust managing agents. The buck always stops with you.

Reply to the comment left by Neilt at 31/01/2023 - 14:57
You are making an assupmtion that the managing agents had some responsibility here (not to say the don't but we just don't know). The landlord may actually have left the heaters on themselves (it happens). Did the agent have a brief to inspect vacant property? In our firm we do not inspect vacant property unless instructed.

Overall, I think you have to chalk this one up tobexperience as an unfortunate incident and move on. I don't think you'll be able to prove anything.

Are there any neighbours you can ask?
Also, as a few have said, if you have smart meters you can at least identify exactly when it happened.
If you Google "n3rgy data" you can download half hourly consumption data from the DCC.