Posted by: Graham Archibald on 16 May 2008 at 6:33pm
Bob, You make a very valid point, oil is still cheaper that Electric I have oil, Rayburn, so heating water and cooking in a large 6 bed house and my oil bill for the year is the same all but a few punds a my pairents 3 bed slemi and they use Eco 7 for heating and hot water and have an electric cooker. Your Heap pump (Air Con) argument looks very interesting. Eco 7 with Heat Pump Air Con, now that might be the way forward
Posted by: Andrew on 16 May 2008 at 9:18am
We were using over 100 litres a week and thought somebody had been stealing our oil. The man who serviced our boiler told us to set the timer to come on for 10 minutes every half an hour (we have a peg clock).
It is amazing, in one month we have used the equivalent of what we were using in one week.
The theory is simple, it only takes a little energy to keep the water warm than it does to heat cold water from scratch. The same principle for running a hot tub.
Now we have hot water on demand and it is costing us a fraction of what it use to.
Posted by: Howard Jacques on 11 May 2008 at 3:20pm
Fed up with paying stupid over the top prices for oil we have just invested in solar power to heat our hot water.Yes there is the initial outlay but if like us you are not intending to move in the near future then you will get your money back.We have had it in for nearly 3 weeks and so far we have used no oil or emersion heating at all and the tank is constantly being heated to 60-65 C.We are confident that this system will reduce our annual oil by about 1000 ltrs or approx £600.00,and as the sun is free then there is no vat to pay either!
Posted by: Bob Medley on 9 May 2008 at 12:08pm
Oil v electricity
I'm wondering whether to use my immersion heater instead of the oil boiler & have checked a few forums for opinions.
The calculations seem to pan out like this;
oil = 10.27 kw hr per litre
My Trianco Eurostar 90 is 85.6% efficient (check http://www.sedbuk.com/cgi-local/dynamicv.cgi?page=boiler8).
(Some people might disagree that this is the true efficiency, but there is no other constant to use)
At todays price of c55p I get 8.8kw hr per litre i.e. 6.25p per kw
My current (ha, ha) electricity is 10.36p per kw total, so oil is significantly cheaper compared to the day rate, even if the boiler efficiency is lower than the SEDBUK ratings.
The available Economy 7 rate is 5.07p total but you get caned for 12.2p total for the rest of your electricity, so I do not see any savings there at all (or it's very close) for water heating or indeed storage heaters - and this with oil at a record high.
This is not a 'hurrah for oil', I just want to save money by the way!
Regarding heating my house, I have air conditioners that act as air heat pumps, and they work on a co-efficient of 4 so in winter I put in one kw at 10.36p but get four kw out, so the equivalent is 2.59p per kw hr ergo it's c2.5 x cheaper to use them than the oil central heating.
What do others think?
Posted by: John Johnston on 8 May 2008 at 9:02pm
Re:- hot water circulating pump system.
The following is the way I chose to implement it. It doesn't constitute instructions & if you're not a competent plumber/electrician DON'T TRY IT but get someone to do it.
I got a decent Grundfos standard hot water system pump from E-bay for about £30. Not going to last forever but it will last a long time and for circa £30! Mines been going for about 2 yrs & no suggestion of failure or problems.
Connect into the hot water feed from the tank to the taps to circulate hot water FROM the tank. Ideally AFTER the vertical overflow pipe to the hot water header tank so that any air drawn from the cylinder as a result of the heating process is extracted by the overflow pipe.
Fit the pump so it takes the water FROM the "hot water taps" side of the tank and puts it in at the bottom of the tank. Put the return as close to the inlet (bottom) of the tank as practical. Use an inline single-check valve in order to ensure that when the pump is off, water drawn off by the hot taps can't draw cold water from the feed to the tank via the pump.
I've disconnected the tank thermostat from the boiler system and now use it to switch the pump. Feed to the stat comes from the economy 7 supply (suitably fused!) Make sure the tank stat is set to a temp BELOW that of the immersion heater else the pump will never switch off. Proper operation will be the pump switching off first then the immersion heater. When significant water drawn off at the sinks, pump starts which cools ALL the water in the tank and the immersion heater kicks in again.
Something else to consider in your pipe routing - convection currents occur in vertical pipe sections. Hence, the reason your overflow pipe for the tank should NOT go straight up out of the top of the tank as it will suck the heat out of the tank by convection. Needs to have a 1m horizontal length (ideally). Same applies to your circulating circuit which is why you need to connect as close to the tank as practical.
You may also wish to fit a timer to the supply to the pump which switches off BEFORE the E7 finishes. Reason- in order that if your having a shower in the morning & the water isn't going to heat up the tank fully, at least you have part of a tank piping hot as opposed to a whole tank lukewarm.
Last but not least INSULATE the pipework!
Posted by: Rod on 27 Apr 2008 at 2:41pm
Re John Johnston on 21 Apr 2008 at 2:28pm comment on Economy 7.
I've recently realised this too, and I note with interest your comment John about a circulation pump on the tank to better distribute the immersion heater heat. Have you any advice on how to do this?
Rod
Posted by: Al on 25 Apr 2008 at 9:45pm
I installed a Danfoss BEM5000 Boiler Energy Manager on my oil fired system 2 years ago. Reduced the average yearly oil use from 2650 to 2300 Litres. New, the BEM costs about £220 (I got mine on eBay) plus about another £80 for cable, junction boxes, pipe thermostat and relay that are needed on oil-fired installations. Biggest saving are on milder winter days. It senses the outside temperature and reduces the temperature of the circulating water to the CH automatically. By setting the CH to run for a bit longer than the HW, it also extracts heat from the boiler that would otherwise be lost when the boiler cools after shutting down.
See http://www.bhl.co.uk/uploads/article331/Danfoss_boiler%20energy.pdf
Posted by: John Johnston on 21 Apr 2008 at 2:28pm
We now use Economy 7 water heating with a circulating pump on the tank so it ALL the water in the tank gets hot & not just the to 18". E7 is a lot cheaper than oil.
We also use a multifuel stove (12kW) in the hall, used coal continuously over the winter. Cost approx £500 in coal as opposed to the normal 3000 litres of oil. Stairs act as a chimney for the heat to distribute through the house. Small above (not on) stove to increase heat output. House is continuously warm. Occasioanlly had to put boiler on to top up heat to bedrooms.
E7 overnight oil rads too.
Posted by: Craig on 19 Apr 2008 at 8:07am
Never knew such a thing existed Julie, has anyone got any more information on this, topped up my tank yesterday and have been charged 51.9p a litre, live in Dumfries, is this on a par with everywhere else?
Posted by: Julie R on 18 Apr 2008 at 2:23pm
Has anyone had any experience of using a magnetic fuel saving device on their fuel line apparently it conditions the fuel and makes the fuel burner more efficiently ie: 20%?
Seems easy to fit and quite inexpensive to buy is it too good to be true?
Your top tips for saving heating oil
