High gas usage for boiler.

[John.g]

Somethings not adding up now anyway Steve. (maybe good)
You used 1257kwh of gas, apparently for HW heating. This equates to 43.4kwh/day for that 29day billing period. This equals to 36.9kwh/day at a boiler efficiency of 85%.
Assuming cold water at 12C heated to 60C, Litres of hot water = 36.9*860/(60-12), 661Litres.
This would equate to 1133 LPD at 40C.
Your actual water usage for both May and June was 460LPD for each month so ????.

Don't know how they came up with a estimated gas usage of 60550kwh/annum

 

[John.g]

Water usage looks relatively static - although i cant go back any further than 2020

View attachment 72749



And this is an over view of Gas Usage

View attachment 72751


Also, something that may help. Octopus take half hourly readings on the smart meters. You can see here in the report i got that, when the heating turns off at 9pm, no gas is used over night until the heating turns on again at 6am. If there was a water leak, would i not expect to see usage over night as well? it also tells me that my tanks is relatively efficient at keeping the heat in.

View attachment 72753


on the 9th, it seems like the boiler did fire in the middle of the night

View attachment 72755

You can see from the above that your "present" hourly usage is ~ 0.7M3/30min = 1.4M3/hour=15kwh/hr. or 13kwh/hr useful heat. Are you heating the whole house??.
Maybe turn the cylinder stat down from 60C to its very minimum and use the electric immersion say from 0900 to 1500 hrs tomorrow and monitor gas meter readings.

 

[Chuck]

Water usage looks relatively static - although i cant go back any further than 2020

Er, it was ca 300 litres per day in Feb & Mar 2020 and then jumped up to >550 litres per day and has been slowly declining since then. When do you think that the increased gas consumption started?

 

[stevedurban]

Somethings not adding up now anyway Steve. (maybe good)
You used 1257kwh of gas, apparently for HW heating. This equates to 43.4kwh/day for that 29day billing period. This equals to 36.9kwh/day at a boiler efficiency of 85%.
Assuming cold water at 12C heated to 60C, Litres of hot water = 36.9*860/(60-12), 661Litres.
This would equate to 1133 LPD at 40C.
Your actual water usage for both May and June was 460LPD for each month so ????.

Don't know how they came up with a estimated gas usage of 60550kwh/annum

thanks for much for the detailed response john.g!

Ill try the Immersion Tomorrow and see if it makes a difference.

Does the immersion have a thermostat on it or will it just keep heating the water?

Er, it was ca 300 litres per day in Feb & Mar 2020 and then jumped up to >550 litres per day and has been slowly declining since then. When do you think that the increased gas consumption started?

is hard to pinpoint because the bills were 6 monthly back then, and now monthly.

Im trying to get hold of the orignal bills but Avro went bust - so i cant get them so easily!

Guys i really appreciate everyones input! thanks for taking the time to help!

 

[John.g]

Yes, The immersion will have its own thermostat, probably set to 60/65C. Make a note of the cylinder stat setting before turning down to minimum, it looks like (and should be) set to 60C.

 

[Chuck]

Assuming cold water at 12C heated to 60C, Litres of hot water = 36.9*860/(60-12), 661Litres.
This would equate to 1133 LPD at 40C.
Your actual water usage for both May and June was 460LPD for each month so ????.

I wonder if the flow temperature being used to heat the DHW tank too low for the tank 'stat setting. E.g. if the flow temperature is 60°C and the tank stat is 65° then the boiler will cycle on and off all day keeping the heating loop that supplies the tank hot and, given there seems to be no insulation visible on the photo perhaps the losses from that would be enough to waste 2 kW.

Is there a programmer that limits the periods that the DWH tank is being heated for? It shouldn't need to be actively heated for more than an hour or two per day.

IME, the flow temperature needs to be a minimum of 5°C above the thermostat-determined setpoint.

 

[stevedurban]

I wonder if the flow temperature being used to heat the DHW tank too low for the tank 'stat setting. E.g. if the flow temperature is 60°C and the tank stat is 65° then the boiler will cycle on and off all day keeping the heating loop that supplies the tank hot and, given there seems to be no insulation visible on the photo perhaps the losses from that would be enough to waste 2 kW.

Is there a programmer that limits the periods that the DWH tank is being heated for? It shouldn't need to be actively heated for more than an hour or two per day.

Is there any way to confirm that?

The hot water is on permanently 24x7

 

[John.g]

There is a motorized valve+cylinder stat but apparently HW is on "all day".

 

[Chuck]

Is there any way to confirm that?

Measure the DHW temperature from the closest tap with a 0-100°C thermometer. Check the flow temperature the boiler is delivering, which is shown on on its LCD display.

I don't like the way your cylinder stat appears to be away from the side of the cylinder. It should be secured in place with a strap. If the sensor is not in good contact with the pocket you'll have the boiler running continuously and will waste a lot of heat because the circulation loop will be hot 24/7.

The hot water is on permanently 24x7

Why? How much hot water do you use over the course of a day, and when. A programmer gives a good measure of protection from the above issues.

 

[ShaunCorbs]

Measure the DHW temperature from the closest tap with a 0-100°C thermometer. Check the flow temperature the boiler is delivering, which is shown on on its LCD display.

I don't like the way your cylinder stat appears to be away from the side of the cylinder. It should be secured in place with a strap. If the sensor is not in good contact with the pocket you'll have the boiler running continuously and will waste a lot of heat because the circulation loop will be hot 24/7.


Why? How much hot water do you use over the course of a day, and when. A programmer gives a good measure of protection from the above issues.

Unvented so pocket stat with sensing bulb set to 50dc