Efficiency savings on oil fired boiler

[old wrinkly]

Hi first time of posting on site.

I have been trying to gather information to help me decide whether or not to make changes to my heating system. My bungalow has cavity wall insulation, the insulation in the loft was upgraded in 2003 to 200mm under a government grant scheme and I have just replaced all my UPVC windows with A Rated units so I think I have gone as far as I can with insulation. I have a small LPG gas fire that I use for extra warmth and generally feel good factor although it is only used intermittently.

My boiler is Boulter Boilers Camray 15/21 (rated I believe at 19Kw/65,000 BT) wall mounted external oil fired boiler that was installed in January 1995, replacing a Parkray solid fuel back boiler. I have a 2700 litre(600 gallon) Balmoral tank.

The boiler has been serviced annually since new.

According to the info on the boiler scrappage site it has a SAP seasonal efficiency of 70%, and the SEDBUK rating band is F although I have also seen when browsing other sites that an 80% efficiency is more likely for a boiler of that age.

With the rising cost of heating oil I had been wondering whether it would be prudent to replace the boiler but again, from reading various topics on the net, the general consensus suggests that if the boiler is working the replacement cost cannot be justified by the expected increase in efficiency This coincides with the view of the the engineer who services the boiler who has always said "if it ain't broke don't mend it", only replace it when it packs up.

Having read the info available it seems that I could however save oil and therefore money by upgrading my controls.

Also read that it's more efficient to use the immersion heater for hot water in the summer rather than oil but I am never sure what the respective unit costs are for Kwh heat for oil/electric to be able to make any comparison. As I have economy 7 suggestion is to have a small immersion at the bottom of the tank linked to this but don't think my current tank has the option of an extra immersion.

I should mention that converting to gas is not an option. According to National Grid when I asked, due to my location it would be cheaper to move house!!

At the moment I have a Grundfos Selectric UPS 15-50 pump that runs all the time the heating or hot water control is active. My controller is a Horstmann CentaurPlus C27 and I have the usual Y valve. The cylinder is the standard Copper approx (900MM X 450MM approx) with a PULLIN 27" (685mm) 3kW immersion heater at the top) with a standard cylinder jacket bought I think from Wickes. The tank was here when we moved in 1994 so no idea how old it is. I have a Honeywell tank stat set to just below 60.

The boiler heats 8 radiators of various sizes and 2 towel rails besides hot water. With the exception of the two towel rails all the radiators have TRVs. I don't have a room stat (one wasn't fitted when the boiler was installed) so I control the heating in each room via the TRVs.

I have read that without a Room Stat WILL save fuel because my boiler will continue to fire at intervals at the dictates of the boiler control thermostat to maintain boiler temperature of 80'c - even when All of my TRV's are up to temperature and the radiators have gone cold. By having a Room stat when the building is up to temperature the room stat will stop the boiler & pump until either the hot water or rooms need more heat, in which case the boiler & pump are re-energised.

My initial thoughts are to fit a wireless room stat. Although dearer than a standard hard wired unit I hope this will give me flexibility to site it to the best advantage. My wife is concerned that if we put a standard wired room stat as this would be in the hall (which is where the airing cupboard is) the rooms in the bungalow might be cold.

If I fit a room stat so that the boiler is controlled better will I have to replace the Honeywell C27?

I am also quite prepared to consider replacing the copper tank with perhaps something like a Gledhil foam covered ( a friend has said he has been told this is the best on the market).

Obviously the Grundfos pump, and the TRVs on the radiators and the towel rails aren't excluded from any potential change provided the reduction on my oil bill or overall energy costs justifies the capital cost.

I would be grateful for any advice as to the best way to proceed and recommendations on equipment.

Thanks

I'd like to ask another question not related to myself. Have spoken to a friend about my thoughts. He has gas and tells me that his radiators are heated from his tank not direct from the boiler. Is this correct?

 

[SPECIAL LOCATION]

Hello Old Wrinkly, welcome to the forum...

Thats a lot of opening post to read...

First quick observations....

The C27 is a general purpose 7 day programmable timer, which can be use in a multitude of configurations..

Horstmann Centaurplus C27 Programmer - Screwfix.com, Where the Trade Buys

So I shouldn't think you would need to change that just because you are adding other controls in.

The Hot water cylinder...

You say it is a bare copper jobbie with a wrap-around insulation jacket?

I would have though a modern cylinder with the pre-molded foam stuck onto it would give far better insulation of the cylinder.

AFAIK cylinders have had the foam on them for many years now..

The ones that look something like this, {Picture just for illustration purposes}



---------- Post Auto-Merged at 17:00 ---------- Previous post was made at 16:56 ----------

Wireless stat......?

You say you live in a bungalow?

I would have though its probably just as cheap to stick in a wired stat...

and no hassle of having to worry about batteries failing or any other interference on the wireless stat signals..

 

[old wrinkly]

Hi, thanks for the reply, much appreciated. Apologies for the long, I do sometimes get carried away with making sure I cover everything. Re the room stat & the C27, would fitting a normal room stat prevent the boiler continuously firing and the pump running all the time, as stated in my post. Preventing that seems the first step to look at.

Is fitting the room stat a DIY job or does it need a sparkie to make sure everyting works as required???

Will take a look at the link for the AFAIK cylinder, as you say a modern insulated cylinder would be better.

 

[Doc Hudson]

Welcome to the forum Wrinkly. Central heating wiring comes within the scope of part P building regulations and should be notified to your local council building control, and a compliance certificate obtained. A registered electrician can do all this notification for you. Otherwise a DIY person should notify the council before they commence work. Just to point out 'AFAIK' is the abbreviation for 'As Far As I Know', it is not a brand of cylinder. Hover you mouse over any underlined abbreviations and the full description is shown.

Doc H.

 

[Manator]

For a first post I would say it is a great post, yes there is a lot of reading, but the question is detailed and leaves us with almost all the information to offer any help. From your name, and the grant scheme acceptance I take it you are of pensionable age? If so there is free advise given via organisations like age concern amongs others, always look for approved government schemes and avoid those who are out to make a quick buck.

All newly installed heating systems have tvr controls, but also have a room stat, in fact British gas insist on this if they fit any heating system. Your heating engineer is probably right, your system whilst at the moment is only giving you 70% efficeincy,it could give you the stated 80% for a small cost ( room stat). A new system boiler would cost a lot of money and take years to pay for itself, before giving you the savings you need.

I can only give advise on anything electrical, and your question is far above my own capabilities to give an answer that would satisfy your request. Welcome to the forum and have a good search around for free information, avoid any salesmen who want to take your cash.

 

[old wrinkly]

Thanks for the replies. Hadn't realised about the abbreviations, will bear it in mind for the future. Yes I am a pensioner and the spiralling cost of heating oil is a real concern, hence my thoughts on how to conserve my consumption. Compared to friends of my age who have dual fuel tariffs my heating/hot water costs are much higher and there is no regulator to fight for consumers who have no option but to use oil.

Higher energy costs are I fear a fact of life but anything I can to keep it under control is a help.

 

[Manator]

Have a word with age concern they should be able to help with any detailed information, look for the safe trader register in your area, they are registered with trading standards and should be able to give you some very good advise. Good luck, and let us know how you get on.

 

[PC Electrics]

I deal with a lot of customers who only have oil or electric. Here in SW Leics there is no mains gas outside Lutterworth or Broughton. The spiralling cost of oil is a major concern to many.

One of my regular customers is installing an air souced heat pump on economy 10 electric tarrif. Have you considered this option as a replacement 'boiler'? Worcester Bosch do nice ASHPs that can be used as replacement boilers and WB have an excellent reputation for quality and reliability.

Have your HWC replaced by one with moulded foam insulation. Then put two jackets on it. You'll have almost no heat loss from it then. The standard for foam lagged tanks is 2.4kWhr per 24hrs (equivalent to leaving a 100W light bulb on constantly). With 2 jackets you'll cut this to about 20W.

 

[old wrinkly]

Thanks, I did in fact look into that last summer but concluded that the capital cost, quoted at

 

[steptoe]

old wrinkly, what type of Air Source Heat Pumps have your friends installed ?

most of the ones I have seen are simply modified air con units, about as much use as **** on a boar ,

you really need a dedicated designed ASHP, I done one in London not so long ago and even in the very cold weather we had it was still heating the bungalow,

yes, you need to oversize the radiators, but you are getting your heating/hot water almost for free on a properly designed and installed system.

although, you may well be correct in your assumption of your age not being beneficial to your outlay vs running costs and payback time.

cheap alternative is as has been said,

TRVs all round, room stat (possibly a programmable one), and a good foam covered hot water cylinder.

 

[old wrinkly]

Thanks Steptoe, interesting reply. The ASHP I was quoted for by Ice Energy was Last July was a Mitsubishi EcoDan W 140 14kW Air Source Heat Pump (Single Phase) priced at

 

[PC Electrics]

OK so the return on investment is an issue for you. I can see why you wouldn't want to go down the ASHP route now.

However I believe you are wrong to dismiss some form of electric heating. The off peak tarrifs are designed such that the overall cost of running heating using off peak electricity or gas have approximate parity. Of course, electric heating is very expensive if it's run on a standard day rate tarrif.

You mention that friends with elec/gas have roughly half the cost of bills compared to you. Well if you moved to getting some (or all) of your heating from off peak electricity then you should be able to achieve near parity with these friends.

So how about this idea:

Have an electric boiler installed in parallell with your oil boiler.

Have a new HWC installed with both immersion and indirect coil

Have an economy 10 tariff for your electricity.

Then run your heating on the electric boiler during the economy periods of the day and the oil boiler during the peak periods.

Also provide your hot water during the economy periods using the immersion and top up only by oil.

With 3 off peak periods (and 10 hours) per day you should be able to provide all your hot water by immersion. This will remove the load from the electric boiler and allow it to concentrate on heating. It'll also mean you shouldn't need to use either boiler for hot water during the summer.

Do you really need or want a mains pressure HWC? This adds considerably to the intallation costs and thus affects your return on investment. If you need a pressure boost for the shower use a power shower or a shower pump.

For that matter why replace the HWC at all? You can stem the heat loss by fitting 2 or 3 jackets to your existing tank for a fraction of the cost of replacement. And you could still add a pump if you need the boost.

---------- Post Auto-Merged at 10:46 ---------- Previous post was made at 10:00 ----------

I've also just worked out the relative costs of the energy in pence per unit (ppu)

I'm sure I'm paying about 4.5ppu for E7 leccy

Using your latest price per litre you've quoted above and looking up the calorific value of diesel oil and factoring in a 75% efficiency for your boiler (bear in mind an electric boiler and immersion are 100% efficient at the point of use), you are effectively paying 8.4ppu with oil. That's almost double the E7 rate. So you can see that shifting some of your energy spend from oil to E10 will save you money very quickly.

 

[old wrinkly]

Hi PC, another interesting post, going dizzy with all the options. Have never considered a secondary boiler i.e electric. I am assume I have a coil in my HWC, at least that's what a friend said I probably have and I already have a 27 inch 3KW immersion heater.

Both my showers are power. The main en-suite is an Aqualisa Quartz and the "guest" bathroom has a pump in the loft.

Have been looking at prices for 80mm jackets for the HWC which seem the recommendation these days and they are around

 

[gordy71]

Having a room thermostat would greatly improve efficiency. Do you have a cylinder thermostat? Is your programmer 2 channel, with the ability to time the c/h and h/w separately? You are best off putting the thermostat in the coolest room in the house, normally the hallway and not a room with trvs as the room stat may never reach temperature. Also set your boiler stat at 3/4 maximum setting. The theory behind this is that the hotter the internal temp of the boiler is, the hotter the rads, the sooner the stat will cut, and higher residual temperature will keep the rooms warmer for longer.

So i would say your first port of call would be the control upgrade and maybe new insulated cylinder. Its worth looking into government grants if you do ever need your boiler replacing. I think a company called Eaga still have the contract for all the boiler installs. Hope this helps.

 

[old wrinkly]

Hi gordy71, thanks for the reply, apologies for the delay but only just picked it up. yes I have a two channel programmer and a cylinder stat.

My plumber is coming Tuesday evening and I am going to discuss various options with him.

Since my initial post I have been communicating with Wharf Plumbing about their Air Source Heat Pump to work in conjunction with my oil boiler. Initial figures suggest it would be cheaper to run, subject to me making changes in my heating controls, than using oil but would allow me to retain oil as a backup, and with a capital cost of around

 

[PC Electrics]

[No message]

 

[old wrinkly]

Happy to oblige:Air Source Heat Pump | Wharf Plumbing

 

[steptoe]

hopefully I am wrong,

but,

Im pretty sure they are air-con units reconfigured,

if so, then they wont work at low temperatures,

well they will work, but they become so inefficient it would cost more to run them than is beneficial.

---------- Post Auto-Merged at 18:00 ---------- Previous post was made at 17:55 ----------

try here

Global Energy Systems Heat Pumps - Reduce bills and cut emissions with air source heat pumps - Case Studies - New Builds

 

[old wrinkly]

Hi steptoe. I hope you are wrong but anyway this was already on my list of questions to ask once my plumber had visited and I knew more about any plumbing changes etc. The site states Fitting an 8KW unit into a three bedroom detached house and using an existing oil boiler as a back up (but rarely have we needed it) we can get the house to 21C using the heat pump in conjunction with a programmable room stat, this can be achieved to temperatures outside being 0C, below this figure and for every 1 degree drop outside the temp will roughly drop by 1 inside, so @ -5C outside you can expect 17C inside hence the need for some backup but you can also see that not much is needed and when is it ever -5C outside ALL DAY long?. There is also a graph showing the ASHP will provide 7000 watts at 2C.

When I first looked at the Ice Energy ASHP I was "warned" to avoid installing a reconfigured air-con unit, due to their lower performance.

 

[steptoe]

what happens old wrinkly is that most of these units have an inbuilt 'immersion heater' type arrangement going on,

so if they cant get the temp up then the heating element kicks in,

so you can imagine how inefficient this is going to be.

and, the thing is, how will you know if this is happening or not?