Diesel Bug - in domestic heating oil?

[Morat]

I guess this isn't really boating, but....

Our home boiler is clogging up on "dirty oil" which is a first for us. The boiler guy hasn't heard of Diesel Bug, but is it a possibility? The tank hasn't been filled since July so anything stirred up by the delivery should have settled long ago.

Cheers,

Morat

[cuthound]

Yes, the bug forms in the interface between the oil and any water in the tank. The water can get in there from condensation, a leaking fill point or a leak.

 

You should dip the tank annually with water finding paste on the dipstick. It will go red if water is present. The water should then be drained off.

 

Do this and then treat the tank with a biocide such as Marine 16 to kill off the bug. You should be OK then.

[churchward]

I guess this isn't really boating, but....

Our home boiler is clogging up on "dirty oil" which is a first for us. The boiler guy hasn't heard of Diesel Bug, but is it a possibility? The tank hasn't been filled since July so anything stirred up by the delivery should have settled long ago.

Cheers,

Morat

Yes it is a possibility. Less likely due to the amount of time spent in the tank often and the cleanliness (and freshness if you like) of the oil delivered but where there is diesel and water mixed it can happen. Also most tanks are plastic bunded units these days so less likely to get condensation dripping into the oil.

 

Some people do use additives to help the fuel and the water content and people like AGA/RAYBURN do recommend their use. However they get expensive when using the quantities of fuel that we do domestically.

 

The alternative is just that some deliveries have been a bit "dirty" and you got some sludge/grit with your oil.

 

Is the deposit black and sludgy goo? If just bits and grit it probably isn't bug.

 

have a look at the fllter on the main oil tap on the tank and see what is in there.

[Ex Brummie]

I guess this isn't really boating, but....

Our home boiler is clogging up on "dirty oil" which is a first for us. The boiler guy hasn't heard of Diesel Bug, but is it a possibility? The tank hasn't been filled since July so anything stirred up by the delivery should have settled long ago.

Cheers,

Morat

Never seen diesel bug on kerosene domestic heating oil, and I see a lot of that. If your tank is plastic, check that the top has not deformed around the filler cap causing a reservoir in heavy rain. Also check the gasket for the contents gauge, and also whether the vent is clogged with vegetation or similar allowing a capillary action. A test with water finding paste will show contamination, and if present, then if a plastic tank without a drain point, a tube on a cane pushed to the bottom of the tank can be connected to a vacuum pump to withdraw the contamination. For around £20 you can get a manual pump with a 5 lt reservoir.

If a steel tank, then there will be a drain cock, to enable you to drain off the contaminant. Steel tanks collect condensation which progressively settles over time.

You will find that the oil pipe will clean easily once clean fuel is drawn through it, but you need to make sure the filters are replaced, including that in the burner fuel pump.

[rjasmith]

Likewise, as a user of Kerosene (28 sec heating oil) for one boiler in the house plus another in an outbuilding for the last 31 years, I've never found any problems with bug sludge in filters etc.

 

Both installations still use steel tanks which are out in the open and have good steel screw cap lids although they have plastic vent caps.

 

I check occasionally for water in the tank bottom but have never found any, nor anything nasty collecting in the outlet filters.

 

Of course it will happen now I've tempted fate I suppose!

 

Richard

[churchward]

Likewise, as a user of Kerosene (28 sec heating oil) for one boiler in the house plus another in an outbuilding for the last 31 years, I've never found any problems with bug sludge in filters etc.

 

Both installations still use steel tanks which are out in the open and have good steel screw cap lids although they have plastic vent caps.

 

I check occasionally for water in the tank bottom but have never found any, nor anything nasty collecting in the outlet filters.

 

Of course it will happen now I've tempted fate I suppose!

 

Richard

I installed a new tank this year by our house to fit a larger one bunded tank and the old one was to close to another building. I took the opportunity as it was easier to lay a complete new pipe from the new tank to the house and the fire shut-off. It was interesting to see that the old pipe (it was of many years of age) was pretty full of crud I don't think it was bug though but it was black and the filter bowl at the tank tap was full of it when I drained the old tank.

 

Still, all bright and shiny now and certified.

 

I have never had the bug in my narrowboat tank either but some do get it.

 

I suppose a factor in this possibly happening these days even in a domestic scenario is the use of a percentage of BIO in the fuel. Although I am not sure how much if at all is in Kerosene heating oil.

Edited December 30, 2015 by churchward

[David Mack]

About a month ago I allowed the water level in our domestic heating tank to rise to the point where the boiler was trying to burn water. Problem was easily enough solved by dropping a pipe down through the fill point and syphoning out the water from the bottom. As I got to the water/oil interface a number of whisps of black stringy stuff came out in the water, although not in a huge quantity. The filter before the boiler was caked in black slime, although it had been changed this summer (so was changed again). So perhaps we have the beginnings of diesel bug!

[Theo]

Never seen diesel bug on kerosene domestic heating oil,

 

I have. We useed that and had the dreaded bug.

 

N

[Ex Brummie]

Diesel bug is generated in the Bio content that has been added to 35 sec gas oil for the last few years. There is a smaller amount in road diesel, but domestic heating oil does not have any organic content at present. The black slime found in domestic heating tanks is usually due to organic ingress from nearby vegetation through the tank vents. Dead leaves break down into dust which is nigh on invisible in the air. There is also the possibility that some minimal contamination may occur at the distribution depots, and again at the point of delivery because hoses may not be properly flushed.

[Morat]

Thanks for all your replies. We've had the filters changed and the boiler is running fine (for now). I'll dip the tank and see if there's anything horrible in there. It's a plastic tank, but un-bunded. If a replacement is necessary then I guess it'll have to be moved because it's next to the coal/wood shed and also very close to our neighbours kitchen - separated by 5ft, 4 of which are vertical! fun fun fun.

[cuthound]

Diesel bug is generated in the Bio content that has been added to 35 sec gas oil for the last few years. There is a smaller amount in road diesel, but domestic heating oil does not have any organic content at present. The black slime found in domestic heating tanks is usually due to organic ingress from nearby vegetation through the tank vents. Dead leaves break down into dust which is nigh on invisible in the air. There is also the possibility that some minimal contamination may occur at the distribution depots, and again at the point of delivery because hoses may not be properly flushed.

I have known about diesel bug since the late 1990's, so it easily predates the addition of vegetable oil to make bio-diesel.

 

Edited for spillung.

Edited December 31, 2015 by cuthound

[ditchcrawler]

I have known about diesel bug since the late 1990's, so it easily predates the addition of vegetable oil to make bio-diesel.

 

Edited for spillung.

I never came across it but it was something we discussed when I worked Offshore, one of the mechanics who was ex RN had experience of it so it goes well back. Even hydrocarbons straight out of the ground will grow things with water and oxygen.

[Tony Brooks]

A few years ago on one of my course in Reading I was explaining diesel bug and how not to suffer from it and was experiencing a degree of disbelief from most of the boaters. An ex RN chap told then it was not a load of nonsense because it was well known, especially when they had used water ballast in empty fuel tanks to make up for the used fuel.

 

A chap who worked with fuelling at Heathrow then chimed in and said they also have to take precautions and be very careful to avoid it. That suggests to me the 28 second heating oil could well be subject to diesel bug as it is very similar to commercial jet fuel.

 

Incidentally this took place well before there was any question of adding bio to fuels. The bio, being organic, is more prone to biological breakdown than mineral fuel oils.

[cuthound]

I know that the sulphur content of red diesel has dropped over the years to meet tighter legislation. In the early 70's it was 5%, now it is 0.001%. Also the introduction of bio-diesel has greatly increased the abi!ity of diesel to absorb water.

 

These two things together are the reason why diesel bug is increasingly common.

[mango]

A few years ago on one of my course in Reading I was explaining diesel bug and how not to suffer from it and was experiencing a degree of disbelief from most of the boaters. An ex RN chap told then it was not a load of nonsense because it was well known, especially when they had used water ballast in empty fuel tanks to make up for the used fuel.

 

A chap who worked with fuelling at Heathrow then chimed in and said they also have to take precautions and be very careful to avoid it. That suggests to me the 28 second heating oil could well be subject to diesel bug as it is very similar to commercial jet fuel.

 

Incidentally this took place well before there was any question of adding bio to fuels. The bio, being organic, is more prone to biological breakdown than mineral fuel oils.

Straight diesel is organic too. It's a mixture of alkanes and other organic chemicals. 'Mineral' oil refers to its source.