Mixing fuels for oil heating

SusieT

More from curiosity at the moment, but google is giving conflicting results. I am looking at getting a new condensing oil boiler to replace the ancient/old one that I have at the moment, as with the saving in oil from better efficiency it could pay for itself in a reasonable number of years. In the details about them some are saying that they are manufactured to be able to run on all available low sulphur fuels, and also Bio 20, parrafin type heating oils and I think I saw one that said vegetable oils (although that could have been part of the Bio oil?). Obviously I only have 1 tank, so when the different oils come into more regular use and availability, can they be mixed in the tank or does it need emptying, cleaning and a complete switch to the new type of oil? 
I know this is for the future when other oils are easily available and cheaper, but thought it worth asking while I am thinking about it.

lohr500

I think it is very much dependant on the make/model of the boiler.
My Grant Vortex Blue, which was new last year, cannot run on Bio kerosene.

But according to the installation manuals, the non Blue versions of Grant's oil boilers can run on Bio kerosene up to B30, with no internal modifications or changes to the jetting. Checks are required however on the external components as per the info below :

OPERATION ON BIO-FUEL All Grant Vortex condensing boilers manufactured since May 2011 are suitable for operation on both standard Kerosene (Class C2 to BS 2869) and also bio-kerosene - up to a 30% blend (B30K). All burner settings and nozzle sizes (as detailed in Section 2.2 of these instructions) are correct for both standard kerosene and biokerosene (B30K). In order to operate this boiler on bio-kerosene, it will be necessary to take the following actions: • Use a bio-kerosene (B30K) compatible flexible oil line in place of the oil line supplied with the boiler. • Have the oil storage tank and oil supply line (including all pipework, sight gauges, filters, isolating valves, fire valves, de-aeration devices, etc.) checked for their compatibility with bio-kerosene (B30K). Where necessary, some or all of these items may have to be replaced with a bio-kerosene compatible alternative. • Check the suitability of the flue system with Grant UK. • Use only bio-kerosene (B30K) that conforms to OPS24. IMPORTANT: Under no circumstances, should the boiler be used with bio-kerosene without the above actions being taken first.

My interpretation of this, is that subject to checking that the external components are compatible with bio kerosene, you could mix regular and bio kero in the same tank if you had a Grant Vortex boiler (non Blue version).  

I can't find out a great deal on vegetable oil (HVO), only a statement in a Grant brochure which states :

HVO Compatible All new Grant Vortex oil-fired boilers are HVO (Hydrotreated Vegetable Oil) compatible.*  HVO is a biofuel which is a type of renewable energy made from organic matter and waste materials and, as it is a second-generation fuel, it eliminates up to 85% of net carbon dioxide emissions compared with traditional fossil fuels, as well as achieving lower NOx emissions. HVO can be used as a ‘drop-in fuel’ so it is a suitable replacement for existing fossil fuels like kerosene, providing a 100% biofuel option. Significantly lowering carbon emissions of home heating systems, HVO has a part to play in the transition to Net Zero. *recommissioning required

As recommissioning is required, I suspect that the boilers will need changes to the burner nozzle size and air mixture settings.
So I think switching to HVO will be a one off change involving draining the existing fuel from the tank and pipelines as well as modifying the boiler. I could be wrong though.


All the above is based on little knowledge, just a trawl through available info on the Grant website.

I would ask the specific questions with the manufacturer once you have narrowed down your choice of boiler.

As an aside, we are very happy with the Grant Vortex Blue boiler we had installed early last year. We also replaced an ancient Myson non condensing oil boiler. The 10 year parts and labour guarantee on the Blue model was important to our boiler choice, as was the ability to locate the new boiler outside and free up room in the kitchen.

Through careful monitoring of our oil consumption using an in-line fuel tally counter, we are saving well over 35% in terms of oil consumption with no changes to run times or room temperatures.  Most of the saving will have come from the improved boiler efficiency (70% to 95%, published figures) but also from optimising the flow and return temperatures and changing the plumbing from gravity fed hot water to a Y plan system.  

SusieT

Thank you very much for that, it makes a lot more sense than the things I have read and got cnfused by!   Inteesting that you saved 35% plus, as I was calculating less than that, so it is possible that payback would be sooner than I am expecting which will be a bonus.  The Grant boilers are on my list of probables for the change over, so that first hand information is very useful for me

ispookie666

I replaced a 40 yr old Myson with Firebird last year and the best decision (we have only lived at this house for 2 years). 
First year we went through Approx 2000L (old boiler)
This year I purchased 1800L and my 1200L tank is full. I think that's 600ish L with the new boiler. 
At the current price that's just above 1000 per year in savings.

I'm hoping HVO will become mainstream. I wish there was better availability of kerosene generator to future proof against any blackouts. 

The elephant in the room - I have had solar diverter installed in Jan, that has reduced oil consumption a lot. 

SusieT

ispookie666 said:

I replaced a 40 yr old Myson with Firebird last year and the best decision (we have only lived at this house for 2 years). 
First year we went through Approx 2000L (old boiler)
This year I purchased 1800L and my 1200L tank is full. I think that's 600ish L with the new boiler. 
At the current price that's just above 1000 per year in savings.

I'm hoping HVO will become mainstream. I wish there was better availability of kerosene generator to future proof against any blackouts. 

The elephant in the room - I have had solar diverter installed in Jan, that has reduced oil consumption a lot. 

That is a huge saving, sadly I will not have your elephant, even without it there seem to be big savings possible