Large Electricity Bill

alexandrakisdimi

david1951 wrote: »

Pretty sure this isn't allowed (emphasis added)

I have already requested access to the meters from the management. The meters are in a locked room in the basement and the caretakers usually get the readings. But since there is a smart meter installed there was no need for them to give me a reading yet. Since there is a issue though I asked them to give me access with the presence of the caretaker.

Heedtheadvice

alexandrakisdimi wrote: »

....
I can only think of that the water heater has a heat loss and keeps working for 5-6 hours a day. And yes it radiates heat, but the flat is generally warm. maybe 18 degrees. I don't get usually cold, i even sleep with no duvet at night

...and there you might just have your answer!
6 hours at 3kW is 18 kWh -if it was on full all that time, but let's assume 50% time, even that is about £1.50 a day (at above assumed unit rates)......so would account for over £100 a quarter....

alexandrakisdimi

Heedtheadvice wrote: »

...and there you might just have your answer!
6 hours at 3kW is 18 kWh -if it was on full all that time, but let's assume 50% time, even that is about £1.50 a day (at above assumed unit rates)......so would account for over £100 a quarter....

I will have a look at it. First thing I will do is check with the monitor the consumption with the boiler on, and then with the boiler off, if there is a significant difference then I will know the source of the problem. Any way possible to check the boiler for heat loss?

Heedtheadvice

Yes.
A simple way is to feel the heat with your hand. If it is hot then you are losing lots of heat, if cool then efficient insulation -assuming it is insulated all over!
You can get an approximate measurement by heating up the water to it's maximum thermostatically controlled temperature (can you measure it?) allowing it to stand for a few hours without using any hot water (say during the day when you are out) with the electric heating to the boiler switched off, measuring the temperature again after a few hours (say when you come e back home again) and then switch on the heating to it again and measure how much electrical power it needs to get back to set thermostat set temperature again.

That will not give you a figure for loss per unit area but will give you a figure for how much energy you lose from the cylinder over time (as a sort of average). It will be something similar to what it 'wastes' as a loss.

It is not quite as straightforward as that but should give you a good impression. Obviously the hotter the thermostat, the poorer the insulation and the cooler the surroundings, the bigger the quantity of water stored, the greater the loss. Keeping the thermostat lower, improving insulation will help as would (remember a previous poster's comment?) heating a smaller volume also helps reduce power loss.

Hope that helps.

alexandrakisdimi

So I did my research two days now and came to the conclusion that the boiler is the source of all evil.

Boiler turned off for a day, being out from 6am to 11 pm, 4kwh. Consumption overnight from 12am to 9am 1,5kwh. So far so good.

Morning came, boiler on for maybe 2 hours, oven 5-10 minutes, hob element 15 min, 14kwh. In 3 hours total. Here I should point that oven is 2,15kw and large element 1,8kw.

I was confused at one point for the amount given and started monitoring the meter while turning on and off appliances. Oven reading ok, hob reading ok. TV, fridge, freezer, router, android box, soundbar and a lamp 300-400w combined. All good.

Boiler on: varied from 6-9kw. That was interesting. Went up to the main control, turned off boiler, left it off. And then it hit me. There are 2 switches for the boiler, that was strange. Went to the boiler room looking around and got my answer. So the main cylinder/hot water storage is an indirect unvented water heater 180 liter with an immersion heater of 3kw. And surprise surprise, behind that is an electric flow boiler of 6kw

Now I am not familiar what this does and why I have a combination of Immersion heater and flow boiler but I get why I see those numbers on my monitor and so high consumption. Oh, and guess what. It was set to maximum and Immersion to 85 degrees (turned it down to 60 and flow boiler to minimum)

So the question is, what does this system do and why I have both? do I need both turned on for hot water? If not, Which one should I turn off? Is the flow boiler needed for central heating?

Sorry if these questions are stupid but I originate from Greece where we use solar panels to heat water all year, and diesel boilers for heating during the winter. These kind of boilers are not my expertise

Apodemus

Sounds like you are getting nearer to a solution! It will be interesting to hear how your shower temperature is with it all turned down.

Heedtheadvice

Πρόοδος! Καλή τύχη.

It is likely that one cylinder is used for the hot water and one for the central heating.

alexandrakisdimi

Heedtheadvice wrote: »

Πρόοδος! Καλή τύχη.

It is likely that one cylinder is used for the hot water and one for the central heating.

Thanks. The two switches though are 1. Boiler Controls, 2. Boiler. The first one turns on the panel that controls HW and CH, sets timer etc. and the 2nd one turns both the water heater and the flow boiler. So I don't know how I can turn that off. Or even if I should turn it off, or both of them need to be working together.

Apodemus wrote: »

Sounds like you are getting nearer to a solution! It will be interesting to hear how your shower temperature is with it all turned down.

Well the minimum temperature for the flow boiler is 65 degrees according to the manufacturer. It's still pretty hot. To be honest 90 degrees on one and maximum (95) on the other almost burned my hands while doing the dishes. So minimum it is.

I will have an engineer come look at the boiler to check what's going on and give me more info. It could have a faulty thermostat and keep turning on the boilers throughout the day, or the high temperature could have turned on and off the boilers multiple times a day making it a total of 1-2 hours to justify the over 20kwh/day.

I am going to have a small experiment the next days as well, now that I have turned down the temperature:
Day 1 - Normal use, boilers on all day, shower, dishes with hot water
Day 2 - Normal use, boilers off, no shower, do the dishes with whatever is left in the tank
Day 3 - Normal use, boilers on for 1 hour, shower, dishes with hot water
Day 4 - Normal use, boiler on all day, no shower, no hot water all day.

And see what the meter says. I will let you all know of the outcome. It's getting close

Le_Kirk

I would suggest (now you have identified that there is a control - and well done for your detective work) you need to adjust the controls (assuming there is a time switch) so that the heating and/or the hot water switch on to suit your requirements.