Oil usage - High amount used?

skydish79

We have a 2 storey house, it is zoned so heating only heats water, upstairs or downstairs

We have heating on at these times

6am to 7 am for water

7.am to 7.30am upstairs

7.30 am to 8.30 am downstairs

11.am to 12pm downstairs

2.00pm to 3pm downstairs

7pm to 8pm upstairs

Upstairs - 6 large rads , 2 small

Downstairs - 6 large rads, 4 small rads

We have from January 18th to March 3rd used approximately 450 litres of oil.

Does this seem excessive? Or would that be normal? Would have thought with zone system we would be using less oil

Without reducing the number of hours, is there of reducing the amount of oil used

jimf

5 hours on time x44 days 220 hours

if boiler is running 80% of that time 176 hours

depends on boiler size and service record approx oil usage per hour 2.5 ltr

so imho yes your usage is not for off

10-10-20

"Does this seem excessive? Or would that be normal? Would have thought with zone system we would be using less oil" You clearly are using less oil with a zoned system as you can control what zones are heated at any point in time rather than heating the whole house, no?

"Without reducing the number of hours, is there [a method?] of reducing the amount of oil used" Insulation, digital TRV's, lower the target temperature... upgrade windows, etc, etc.

Why not put your heating and water on at the same time and save yourself 1 hour per day

10-10-20

https://www.boards.ie/discussion/comment/118732304#Comment_118732304

Might be worth it for a small efficiency gain (maybe ~5%), but do you want the hot water competing with the rads and will your hot-water be hot enough in time? All questions to be answered.

cruizer101

12 large and 6 small rads is a lot, guessing you have a big enough house, so it would make sense it would cost a decent bit to heat.

Ideally you want to think about it in terms of heat loss. If a room isn't losing heat even when the heating turns on the water won't loose much heat so the boiler will cycle off.

Look at your overall insulation, attic, walls, windows, draughts.

TRV's could be worth looking at, you can get smart ones these days that should allow you to setup a heating profile for each room. That said there are 50+ each so you are looking at 1k for the smart units plus if you have to plumb in trvs you can probably double that.

Wearb

https://www.boards.ie/discussion/comment/118731753#Comment_118731753

Well done JohnG Jimf 🤣. I would have to agree with you. I would also think that with those short on times, there would be closer to 100% on time unless the house is in the C ber rating. 10 rads downstairs, suggests a fairly large house also.

John.G

Probably a big house but usage saucy enough IMO.

I have a 50 year old 4 bed cavity block house, heating is on (enabled) for 16 hours/day, bedrooms kept at 16/17C, 4 downstairs rooms kept at 20/22, TRVs on all rads but one roomstat in combined dining/sitting room, HW zoned to 60C.

January 18th to March 3rd used exactly 341 litres of oil. Filled Tank on March18th and my tank (Carbery compact R) "calibration" happens to be exactly 1 litre/MM so easy to get very accurate consumption numbers. 16 year old 20kw SE Firebird Boiler so assuming boiler efficiency at 78%, then energy consumption/day = 341*10.2/44, 79kwh/day or 79*0.78, 62kwh/day to house+HW. or 3.9kwh/hour.

skydish79 consumption = 450*10.2/44, 104kwh/day or 104*0.78, 81kwh/day to to house+HW. or 16.2kwh/hour. If boiler is HE then assuming efficiency at 85% then 88.4kwh/day to house+HW. or 17.7kwh/hour.

Makes one wonder if its not better to keep heating on continuously like I do for 16hrs/day?.

The roomstat (EPH mechanical) does switch off the boiler fairly regularly and has a hysteresis of 1.5C to 2C.

skydish79

https://www.boards.ie/discussion/comment/118732290#Comment_118732290

We have had the walls pumped, attic indulated got it up to a b2 rating

The target temperature on the upstairs is 18, downstairs is 20

The house is 20 year old

skydish79

https://www.boards.ie/discussion/comment/118732363#Comment_118732363

Yeah we have the hot water on its own just to get enough water for showers in the morning

skydish79

https://www.boards.ie/discussion/comment/118732485#Comment_118732485

The house is around 2800 sq foot, main block would be 4 bed house with a sunroom on one end and a converted garage on the other end

Have done our best to seal up as many draughts around the doors and windows

Wearb

https://www.boards.ie/discussion/comment/118733187#Comment_118733187

If you have a B2 rating, then you dont have many cracks to seal up. but you are certainly loosing heat somewhere.

Where in relation to the house is your oil boiler?

Do you have it properly serviced annually?

What make and model is it?

Is your heating system sealed?

Gant21

BER certs are worth the paper they aren’t wrote on a lot of the time.

As an example below.

Big difference between a Munster joinery window and a senator window yet they both tick the same box.

jimf

a properly serviced and set up with flugas analysis boiler will def save you money

John.G

https://www.boards.ie/discussion/comment/118733176#Comment_118733176

B2 energy rating is 100 to 125kwh/M2/year, say average of 112kwh/m2/year. Your house is 2800ft2 or 260M2 so, theoretically, energy consumption is 112*260, 29120 kwh/annum = 29120/10.2/0.85, 3426 litres/year of kerosene.

skydish79

https://www.boards.ie/discussion/comment/118733244#Comment_118733244

The boiler would be at the back of the converted garage in a room.

I would have put caulking around the window sills where it felt colder

Its a firebird probably 20 year old same as the house

Yeah get it serviced every year

When you say is heating system sealed?

skydish79

https://www.boards.ie/discussion/comment/118733303#Comment_118733303

Do you have any companies that put in place flugas analysis boiler

skydish79

https://www.boards.ie/discussion/comment/118732695#Comment_118732695

When you have it running the 16 hours,

Is that upstairs and downstairs?

or does it just shut off when it reaches your desired temps of 16/17 and 20/22

On your figures you are a lot more efficient kwh/hour

skydish79

https://www.boards.ie/discussion/comment/118733496#Comment_118733496

We probably average around 2000 litres in the whole year

Thats why the 450 litres used in the last 6 weeks seemed unusally high, would have expected 300 -350 litres

Wearb

Sealed as in no small attic tank and a red expansion tank somewhere.

Its apples and oranges comparing your hourly rate with John's. The hourly consumption will reduce once the house warms up. A better comparison would be to compare the daily use of the two houses.

Do you get a report and printed flue gas analysis with each service?

John.G

https://www.boards.ie/discussion/comment/118736619#Comment_118736619

That's u/stairs & d/stairs on for 16 hrs, I have the u/stairs(and all) rads TVR controlled so they just maintain that temperature, same downstairs but room stat will override the lot and shut the boiler down if the dining/sitting room exceeds 23C of if sometimes set lower as we get a lot of solar effect sunshine even in winter (dining/sitting room facing south) so a setting of 18/20C will still give a comfortable 20/22C with boiler shut down for hours.

My house is only slightly more than 1/2 of yours at 140M2 but that would still only account for a pro rata increase to 7.2kwh/hr (260M2) so a long way away from 17.7kwh/hr.

skydish79

https://www.boards.ie/discussion/comment/118736682#Comment_118736682

There is a red tank beside bolier, would that be it?

No we don't get a report/printed flue gas analysis its just our local plumber dong the service

John.G

https://www.boards.ie/discussion/comment/118736652#Comment_118736652

I have averaged 1450 litres/year over the past 12 years, so pro rata would have used ~ 2693ltrs/year for a 260M2 house. 2000 ltrs/year for a 260M2 house would be quite good if heating on for 16hrs/day or 5/5.5hrs/day IF the required house temperature is maintained for 16hrs/day.

Wearb

Do you need to top up pressure often?

Nowadays it isn't acceptable (IMHO) that service people not have a flue gas analyser. For all we know your boiler could be putting a lot of its heat out of the flue. Post a pic of the boiler and flue terminal to see if we can see anything obvious.

Do you have a boiler stove?                                                                                                                                            

jimf

https://www.boards.ie/discussion/comment/118736603#Comment_118736603

https://www.boards.ie/discussion/comment/118736603#Comment_118736603

sorry i may have not been very clear with my post

a flugas analysis is a procedure carried out during a boiler service and a printout of this should be left and explained to the customer

but my experience of giving this to customers is usually met by the comment shur i might as well be looking at a bulls arse

skydish79

https://www.boards.ie/discussion/comment/118737100#Comment_118737100

Gee I wouldn't even know how to top up the pressure or how to check if it needed to be topped up.

No we don't have a boiler stove,

When we moved into the house a few years ago there was a lot of black around the flue on the pebble dash, so we got it serviced straight away and we haven;t noticed a build up of black colour since we've been servicing it

skydish79

https://www.boards.ie/discussion/comment/118737664#Comment_118737664

No its more me not having a clue about anything DIY/trade related

Wearb

https://www.boards.ie/discussion/comment/118737743#Comment_118737743

If it's a fully sealed system and you havent had to top it up, then it's good. But if not and the heating system has a constant feed, it could be leaking and you wouldnt even know until you got some leaking radiators and sludge in the system

If the soot wasn't properly cleaned from the boiler (it's a filthy job) then you would be wasting a lot of heat out of the flue.