I need help as I think my usage is excessive

One of the things with only having the heating on for a short burst of time is that the fabric of the house is never getting to a level where it helps the overall temperature. Your insulation levels might be the most significant factor here as the amount of heat put in quickly leaks away. 
Unless you need those high temperatures, I might try reducing your boiler heating temp to 55deg and your hot water to 50deg. There should also be a setting to only heat hot water on demand rather than keeping a quantity ready (therefore always heating).

I have to admit that at the levels of gas usage you mention, I would also be checking for leaks

Ok  I'll try knocking the temps down i did try leaving heating on all the time for a few days but it looked like it was costing alot so set it to timed again. I know the insulation is not the best as it's solid stone walls and no real roof space for insulation. I think the hot water is heated as needed as u hear.it fire up when the hot.tap goes on

A couple of other thoughts ..

do you have an idea of the equivalent power the old boiler used during a winter month?

and are you sure the 5300kWh is accurate and not an estimate. 

Not sure about old.system and it's what I've been reading so it does look right. I'm just at a loss atm over £300 a month and still feel cold

Hi ​@James anslow 

Can I ask a couple of questions?

I assume this is a sealed system? Expansion vessel and filling loop rather than header tank in the loft?

Do your radiators get hot (too hot to comfortably touch) within say 10 minutes of the heating turning on?

Can you hear the boiler “turning down” after 15 to 30 minutes?

Do you have a smart meter with half-hourly readings?

Working backwards from your 5300 kWh.

Average power usage = 5300 / 30 (days) / 7.5 (hours) = 23.6 kW. I think your boiler is rated 24 kW, so this suggests that your boiler is running continuously at full rate when it is on.

Yes it's a sealed system as no header tank

 Radiators do get hot when it comes on quite quickly. Takes a while for the boiler to turn off

 When I get the thermostat is reading around 12 degs and takes around 1 hour for it to hit 15 to 16. I don't have a smart meter for.my gas as they are not supplying in my area at the minute when I asked.

Our house heats from 15 to 18°C in around 1 hour, so it looks like the heat output from the radiators is heating the room up at about the right rate. I would expect the boiler to modulate down as soon as the radiators get hot. I think your boiler is rated at 24 kW, but should turn down to about a quarter of that (6 kW) as the flow temperature reaches the boiler set-point (I think you said 55 or 60°C). Initially the boiler is heating up the circulating water, but once it has reached temperature it just needs to keep it hot.

The quick sum I did above suggests that your boiler is running flat-out during the timed on periods. However if that was the case I would expect the radiators to be roasting hot (even as hot as 80°C). That would be the only way the radiators could deliver that amount of power into the house (unless the radiators are oversized).

So I need to check that the boiler is modulating down when it should do (when the flow temperature gets near to the setpoint) and exactly how much gas is being used during the 7.5 hours it is on each day.

If you take a series of daily readings, taken about the same time when the boiler is timed to be off (say around mid-day) then you can start to work out your actual daily usage.

Assuming a metric gas meter:

(To-day’s reading - yesterday’s reading) * 11.2  = Daily gas usage in kWh.

Divide this by the on-time between the two readings (6.20am to 8.30 am = 2.1, 2.30pm to 8pm = 5.5, total 7.6 hrs) will give your average power.

In essence I am trying to determine if this is a boiler fault or a meter reading (estimate) problem, or even something like confusion between a metric and imperial gas meter. A picture of the meter might help here.

Hi there, 

I’ve just recently been billed for an entire years worth of gas use in one go. Its ~£800. Now the odd thing is I don’t use any gas at all. Electric cooker, boiler, shower. There is an old gas fire in living room but its 40 odd years old and falling apart - I never use it, never. Covered in paper work I take home (next to my chair). I’ve tried telling them but already I’ve threatening emails (court action) when the bill is just a few days late. I asked for the account to be put into dispute - the gas part of the bill and it hasn’t been. 

Now the really odd thing is on the bills it says based on estimates but on the ‘usage’ section on the website it says readings from smart meter. Now the daily usage cannot be right as it varies hugely often showing me using 4/5x the amount of gas to electric.  And I have had extended periods away from the house, mainly hospital stays and a family holiday yet its over these periods some of the gas consumption is the highest?

I spoke online via email with an OVO who states certainly the bills are based on smart meter data. I really don't think that they are. 

I really have never used any gas at  the property at all. Nut no one will listen - any ideas? It’s deeply frustrating that no one will listen or believe me when I say I have no gas appliances and have never used gas in the property.

Hello there, and welcome to the forum!

We normally cannot comment on specifics of people’s bills, as we aren’t privy to details.  Your situation certainly sounds odd though, to say the least!  Hope you get it sorted soon.

However, one thought occurs, and forgive me if it sounds like a daft question in view of your saying you have had zero gas appliances working in your home over the past year: you don’t have a gas Combi boiler or any other sort of gas central heating I suppose?

Thanks  for time - I could upload a pic of the bill with details redacted if that's allowed? There are 12 bills as this has been backdated 12 months. 

No I have an immersion boiler! Electric cooker, electric shower. Nothing on gas. I even sent them this so they might believe - the bread i don't normally keep in the airing cupboard - It ws to show I hadn’t downloaded the pics - so but the bread in all of them.