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JB

oil fired heating and cooking on gas

Does anyone have a rough idea how much oil I might expect to get through in a 4 bed semi with hot water and central heating provided by an oil fired combi boiler (appreciating that it would only be the vaguest of ball park estimates)

Also we're thinking of rebuilding the kitchen and as we prefer to cook on gas hobs we were going to install a hob suitable for LPG. What sort of housing would we need for the gas tanks? Are there any particular restrictions on where they can be stored?

TIA
Penny Outskirts

Really totally depends on your insulation. We're in a very draughty, oddly arranged, badly insulated, 4 bed, Cotswold stone cottage, and we use around 3 tanks a year (1300 ltr tank). I know others who manage to just use a tankful, so it is very variable.

Cost has more than doubled in the six years we've been here though Sad
Marionb

We are in a 3/4 bed house, with a 1300 litre oil tank too. When the heating was installed (before we moved here) the installer said it would cost a fortune to heat the house... we had the tank filled at the beginning of November and have today had it filled again. Should last through till autumn at least... so we use about 2 tanks a year.

We've got a gas hob too (electric grill & oven) and have got the red gas cylinders stored against the house wall - dont think theres any special regs for them except they have to be stored outside (ie. not in the house).
lettucewoman

we have lpg gas tanks for our park home....dunno how big they are but they stand abut 5 foot high, are orange, there are 4 of them and they are just standing up against the back of the home...cost 63 quid to fill 2 and they (2) last about a month and a half....

....actually its pretty funny come to think of it....we are not allowed to have a wooden shed because of "fire risk", and yet we have 4 potential bombs outside our bedroom window... Surprised Surprised
tahir

Marionb wrote:
We are in a 3/4 bed house, with a 1300 litre oil tank too. When the heating was installed (before we moved here) the installer said it would cost a fortune to heat the house... we had the tank filled at the beginning of November and have today had it filled again. Should last through till autumn at least... so we use about 2 tanks a year.

We've got a gas hob too (electric grill & oven) and have got the red gas cylinders stored against the house wall - dont think theres any special regs for them except they have to be stored outside (ie. not in the house).


Ditto
alison

Are there different grades of heating oil?

I only ask as both our tanks were filled last week and now both boilers have both gone out, more than once, and the aga is burning very cold, (if that makes sense)

We have a boiler for the cottage, and one for the B&B, then the aga is in the house. Boilers run off one tank and aga off the other.

Proberbly they all need a service, but would the kerosene make any difference.
gil

alison wrote:
I only ask as both our tanks were filled last week and now both boilers have both gone out, more than once, and the aga is burning very cold, (if that makes sense)

We have a boiler for the cottage, and one for the B&B, then the aga is in the house. Boilers run off one tank and aga off the other.

Proberbly they all need a service, but would the kerosene make any difference.


How big are your tanks ? Surely you've not run out ?
Burners clogged ?
Airlock in the fuel pipes ?
When were they last serviced / cleaned ?
Gervase

The pipes need to be cleaned thoroughly every year, and many service engineers now recommend replacing the jets and filter annually. The oil shouldn't make much of a difference, but all sorts of crud accumulates in your tank (dead spiders being the least of it) and it can all make its way down to the feed pipe and into the jets.
Jonnyboy

When we were renting a 3 bed semi we went through three 1000l fills a year. But it was an old, crap boiler.
alison

The boilers have never been serviced, they are 3 years old, and the aga is done every 6 months, and is due again.

I am jsut surprised that both the boilers are playing up, since the refill, cutting out etc. Neither tank was empty, as we have a top up contract, which says we will never run out.
Lloyd

Ali, if the tanks are less than brand new, a high pressure fuel replenishment will stir up crap in the bottom of the tank that is then sucked into the lines and hence blocks your filters and jets.

I suspect you have drain off cocks down the bottom to clear the debris if that is indeed the case.
Marionb

We have our oil boiler serviced every year.... necessary to avoid any carbon monoxide scares..... we have a new jet put on at every service
alison

The B:&B / Cottage tank was new, same time as the boiler, but I will suggest that Lloyd, thanks.

I didn't realise there was a CO2 risk with oil boilers too. I thought it was just gas appliances.
Jamanda

alison wrote:
The B:&B / Cottage tank was new, same time as the boiler, but I will suggest that Lloyd, thanks.

I didn't realise there was a CO2 risk with oil boilers too. I thought it was just gas appliances.


Normally hydrocarbons (including gas and oil) burn to produce Carbon dioxide (CO2 )and water. If they burn inefficiently (with not enough oxygen) they will produce carbon (soot) and Carbon monoxide (CO) as well.
alison

I didn't know that. Thanks. Very Happy
JB

Marionb wrote:
We've got a gas hob too (electric grill & oven) and have got the red gas cylinders stored against the house wall - dont think theres any special regs for them except they have to be stored outside (ie. not in the house).


Do they require any housing or do they just stay out in the open? And another thing that Mrs JB was asking the other day - is there any reason why oil tanks always seem to be on full display to the world? Is there anything wrong with hiding them behind a screen?
JB

Jonnyboy wrote:
When we were renting a 3 bed semi we went through three 1000l fills a year. But it was an old, crap boiler.


Was that just the boiler or boiler and Aga? (not that Mrs JB wants an Aga)
judith

JB wrote:
Do they require any housing or do they just stay out in the open?


AFAIK they are fine in the open - my parents had a little tank corral attached to the end of the garage.

Quote:
And another thing that Mrs JB was asking the other day - is there any reason why oil tanks always seem to be on full display to the world? Is there anything wrong with hiding them behind a screen?


They need to be easy to access, I suppose. Our delivery chap arrives at about 6 in the morning so I'm very happy that he doesn't knock on the door at that time.
That said, there's nothing to say that they have to stay on show where they are. We hired a minidigger for the weekend and moved ours across the drive and behind a hedge!
JB

judith wrote:
That said, there's nothing to say that they have to stay on show where they are. We hired a minidigger for the weekend and moved ours across the drive and behind a hedge!


Don't think we can do that - it would put it on the neighbour's drive Very Happy
judith

JB wrote:
Don't think we can do that - it would put it on the neighbour's drive Very Happy


I suppose he might complain just a little.
dougal

Re: oil fired heating and cooking on gas

JB wrote:
Does anyone have a rough idea how much oil I might expect to get through in a 4 bed semi with hot water and central heating provided by an oil fired combi boiler (appreciating that it would only be the vaguest of ball park estimates) ...

Some of the things it depends on:
- insulation and construction detail (the more expensive your energy, the more cost-effective is insulation)
- location (you'd use more fuel in Lerwick than Geenwich for the same house to the same temperature)
- boiler efficiency (a condenser should use about 20% less)
- and the way you use it (not just temp choice and rooms heated, but also auxiliary heating eg from a woodburner and passive solar potential). I gather that numerous teenage daughters can also impact the hot water usage...

Here's a simple guide to some basic domestic oil tank installation requirements: http://www.oftec.co.uk/publications/EG_dom_oil_storage_aw.pdf
Note that if the tank is "in a building" there are lots more requirements. Then there are the requirements for when a 'bunded' (or double skin) tank is mandatory ...

I note the proposal for a combi.
They do save you the space of a hot water tank (and usually a ch header). Modest hot water flowrate is the primary trade-off drawback for a combi. (Less restrictive with a bigger, thirstier boiler.)
Another is that it does rather rule out the use of solar hot water (which needs that tank) and which makes even more economic sense if you are otherwise using expensive oil. A tall slim tank (with the necessary second 'solar' coil) is ideal for solar and minimises the floorspace taken up.


Regarding the LPG hob, I'd strongly suggest that you try and see (& have a go with) an electric induction hob. They really are very nearly as responsive as gas (way better than any other type of electric hob), use less energy (they heat the pan rather than the room), and are cleaner to use than gas.
With induction plus a kitchen blowlamp you don't need gas!

Typically, how much is the wattage of a gas burner de-rated when running on LPG? I know different jets are fitted, but LPG cooking has seemed to me to be much gentler than cooking on mains gas (though this may be due to using low wattage kit, to reduce gas gas consumption - caravans and the like).
sean

Re: oil fired heating and cooking on gas

dougal wrote:


Typically, how much is the wattage of a gas burner de-rated when running on LPG? I know different jets are fitted, but LPG cooking has seemed to me to be much gentler than cooking on mains gas (though this may be due to using low wattage kit, to reduce gas gas consumption - caravans and the like).


Don't know if this is generally true, but I've just checked the manual on our Britannia cooker and the heat output of the burners is the same on LPG as mains gas.
JB

Re: oil fired heating and cooking on gas

dougal wrote:
I note the proposal for a combi.
They do save you the space of a hot water tank (and usually a ch header). Modest hot water flowrate is the primary trade-off drawback for a combi. (Less restrictive with a bigger, thirstier boiler.)
Another is that it does rather rule out the use of solar hot water (which needs that tank) and which makes even more economic sense if you are otherwise using expensive oil. A tall slim tank (with the necessary second 'solar' coil) is ideal for solar and minimises the floorspace taken up.


Wouldn't it be possible to use solar power to heat a tank which is then used to supply the input side to the boiler? (I've no plans to add solar power just yet but I would have thought it would make the boiler more efficient) and for that matter is there a difference between a combi and a condensing boiler? Everything I had seen so far seemed to imply they were the same thing.
sean

I think a combi needs a mains pressure water input so you'd need some sort of pressurised tank.
dougal

Re: oil fired heating and cooking on gas

JB wrote:
Wouldn't it be possible to use solar power to heat a tank which is then used to supply the input side to the boiler?
**Only** if the boiler is specifically designed to permit that.
Almost all gas combi's are NOT so designed. I expect oil combi's to be no different.
Yes, the tank would have to be a (rather more expensive) mains pressure tank.


JB wrote:
... for that matter is there a difference between a combi and a condensing boiler? Everything I had seen so far seemed to imply they were the same thing.
Different things.
But some combi's may also be condensing boilers.

A "combi" is a combination of a central heating boiler (usually for a pressurised circuit) and an instant water heater (like the old Ascot 'geysers') in the same box. Apart from possibly the odd litre or three in some combi's, no hot water is stored. It just gets heated on demand - which is why the hot water flowrate is limited by the power of the instant heater.
A condensing boiler captures more heat from the fuel it burns because it has a bigger heat exchanger (heat capturer), (so it has a cool exhaust - more like 50C than 200C) . So it needs to burn less fuel to get the desired amount of heat.
It gets an extra thermodynamic bonus if it actually runs 'condensing' (cooling the exhaust so much that the water vapour in it starts to condense out - about 53C ) but it is more efficient even if it isn't actually condensing.
Getting that bonus from condensing means running the heating circuit slightly cooler than in a traditional system - which means that to get the same heat into a room you need a bigger radiator.
Condensers are made of corrosion resistant materials so they don't rot in their own condensation.

Solar water heating makes a lot of sense (money and carbon) compared to oil-heated hot water.

Combi's are great for the flats they are designed for.
However, in a household where more than one person at a time may be wanting hot water, (I did note we are talking *4* bed semi), a combi can be a right pain. And inhibit use of solar water heating.
With an evacuated tube solar system, you'd probably not use any oil at all from May to September...
dougal

Re: oil fired heating and cooking on gas

sean wrote:
... I've just checked the manual on our Britannia cooker and the heat output of the burners is the same on LPG as mains gas.
Turns out LPG has the higher calorific value.
Just put it down to my experience being of portable (so likely low wattage) LPG cookers! Very Happy
Treacodactyl

I've just asked someone who uses oil for heating & hot water (tank not a combi) in a 3 bed semi. Two people, one at home all the time. They use about 1400-1500 litres a year.

Incidentally, that's 330 gallons and if used to power something like a diesel small car that's about 20,000 miles. Shocked
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