Oil fired combi boiler - advice on costs / best way to run

rama0927

Hello - I am posting this here, as it is the only relevant place I can think of, I didn't manage to get a response in the household section.

I'm wandering if you guys can help me. I'll give you some information, and ask a few questions I have. I've recently moved into renting a house (I'm a student, sharing 5 bedroom, 2 bathroom) and we have an oil-fired combi boiler (Worcester-Bosch Heatslave 15/19). There are separate settings for hot water and heating, with 5 intensity ratings. There is also a programmer which we haven't used yet. The only utility we are charged for is electric, by coin meter, at 9p per kWh (which as far as I know, is a fair rate, location = Mid-West Wales coast).

I'm just wandering how it works, I sort of know - oil fuel is used to burn, then the heat is transferred with an electric pump (maybe) to heat up water in radiator / heat water being pumped out I assume it is something like this. I only have an interest to think about costs really.

I'm looking at what the most efficient ways of running it are - partly because I hate waste, and partly because I hate wasting money even more! If I had it my way, I'd use no heating this time of year and with the savings use it later in the year / early next, just wear a jumper! I have been trying to promote this idea a little, but obviously I need to consider everyone else too since we are sharing a house and cost - some people prefer a warm house and spend money .

Q1: As I am not paying for fuel, does it cost any more to have heating or hot water on at a higher setting in electricity costs? Or will it only vary slightly? (oil and water is included in our rental)

Q2: Is it better to turn on the boiler at different times, only when it is needed? Or is it better to try and guess certain windows, even if sometimes it may not be used - this is because we are all up at different times, and in the evening there is no real set time to do something (unless I can try and make them use a set time if good money can be saved). I.E with water, I have thought of either leaving it on "ON" with its lowest heat setting through the day when people are in the house - for hand washing / kitchen, or just one big charge on its highest setting, then off until it is needed for a shower or something. (any idea of cost difference / most efficient)

Q3: Regarding heating. Would you say it is better to have a good blast on the highest boiler setting for about an hour, then just using whats left. Or is it better to have a sustained lower setting for say 2 hours. (any idea of cost difference / most efficient)

I would be very grateful of any advice with this, if you know anything about the subject. Or if you have the same type of boiler, or are in the same type of situation you may be able to help.

Cheers

rama0927

Bump, any help with this? My first question is the main one really. Thanks.

Cardew

Instruction manual here:

http://www.worcester-bosch.co.uk/homeowner/literature/discontinued-boiler-literature/discontinued-oil-fired-boiler-literature/heatslave-cf-1519-combi-discontinued-december-2007-literature

Any combi heats water 'on demand' i.e. there is no hot water tank.

The big disadvantage of any combi is that, particularly in winter, you will not have loads of hot water and in a 5 bed student house with 2 bathrooms that will be a problem for sure. If one person is having a shower(obviously not an electric shower) or running a bath, and someone turns on another tap, the flow of hot water for the first person will reduce. No way around this - you will have to live with the situation.

The heating is just like any other CH heating system. The Hot water is pumped around the radiators by an electric pump. The Timer determines what period of the day the heating will come on.

There should be Thermostatic Controlled Valves(TRV) on all but one radiator - get people into the habit of turning them down when they are leaving the room for any period - a concept most students seem to find difficult to grasp!!!!

Are you sure you won't pay for oil? it could cost the landlord £2,000 pa or more

Ban the use of Fan Heaters in rooms!!!!

macman

I find it incredible that any landlord would allow unlimited use of heating in a student house!
Are you sure you don't just get one tankful every x months and when that runs out that's it for the winter?
As Cardew says, a combi only provides hot water when you turn on a hot tap, so there is no potential wastage with that.
The longer you have the heating on, the more oil you will be burning.

Swipe

As a student, I was in a house share in Sheffield where the bills were included in the rent (back in 91/92). As you can imagine, we spent the harsh northern winter in T-shirts and shorts with the house temp at ~25C. I can honestly say, I've never had so many colds in my life as the two years in that house.

rama0927

Cheers for the advice guys, and info.

As far as I know its correct that I apy for electricity only. When we applied and moved in, the landlady said water rates and oil for heating were included. I'll just point out that this is a house in the country, which is 2.5 miles away from Aberystwyth university, we are paying over £1250 per month for between us (£65 each per week, about the going rate for student accommodation, in the Aberystwyth area), I reckon this house would be worth no more than £700 pcm to anyone but students I reckon. So they probably factored it into the price.

I'm trying my best to make energy savings, and asking others to, but some people aren't bothered which is very frustrating - Computers left on idling, lights left on, TV left on, heating on when not needed etc, but I can only harass my friends so far. I told one person his computer was left on, he just said "at least my monitor is off" and carried on playing his game in the living room - 'sleep' / 'hibernate' is so quick and easy, I just don't understand the way some people think. I don't think some of them consider that its other peoples money they are wasting, not just their 1/5 which they pay. I have however managed to keep the heating off for a week now I think, but someone has been putting things in the dreaded dishwasher so that'll be munching soon. Our weekly electricity use is currently 106 - 116kWh (I take readings every now and again just to monitor things).

@Caredw / Macman - When its turned on, but no hot water / heating is not needed, you can still hear it working away - is the reaction really live on demand, or do you have to wait for it to build up pressure or anything like that, before it does turn on and on demand?

@Caredw - I think there is very little chance of that happening with the radiator valves, they just wouldn't be bothered in doing that unfortunately (well a couple of people I live with might). I have turned them down around the house, especially in areas where it is not really needed. It doesn't matter too much at the moment, as the heating has only been on for the odd hour since I moved in, and not at all in the past 7 days - I'm trying to get them in the habit of wearing jumpers haha.

BTW this topic makes me look like a right Nazi haha. Never mind, most things are sensible, I realise that I may be a little more extreme than normal.

macman

£10-£12 a week for electricity in a 5-student house is really quite low.
With a combi the boiler is off until you turn a hot tap on (assuming the heating is off)-no gas is being consumed, only a little electricity to power the standby circuits.
Your student pals may modify their behaviour when they ge tthe first electricity bill...
I still don't see why the LL would pay for oil but not for electricity-the cost of the latter is going to be much more predictable with oil CH installed.

G_M

The real expense for central heating and hot water lies in the oil usage, not the electricity which is minimal - just the pump basically.

If you are lucky enough to have your oil paid for I would stop getting concerned about the electricity usage on the boiler and focus on other areas of electricity: TV on standby all night, lights left on etc.

rama0927

Ah right cheers. Electricity is paid for by coin meter, so we are just putting 5 pound coins each into a box occasionally, then feeding it in when needed. Oil has just been supplied to us, on the advert it said it was included, and they haven't mentioned any costs of it since. I'll stop getting as worried about heating then, and concentrate on computers, tvs and lights going off etc. Someone has bought a tumble drier now though, oh joy. At least electricity is pegged fairly cheaply though, its at 9p per kWh, and at what I can make out there may be an additional £1 per week standing charge (which may or may not be in force). A friend of mine has his at 15p per kWh so we've got off lightly!

Thanks for all the responses, I'll "thank" a few people now.

macman

A tumble drier is a sure-fire way to burn through lots of power in a very short space of time...