Upgrade to condensing boiler - do I need to clean the gas oil tank?

We are replacing our boiler with a condensing boiler. Our fuel tank is 1/4 full of gas oil which we will empty before filling with kerosene. Do we need to clean out the tank, and if so what is involved?

i have an old oil boiler and was considering the same idea,(replace with condensing one).the other option being to change to gas.can i ask if you considered gas and also how much the new condenser system cost.

Piped gas not available here & didn't consider getting tank. Cost of job just under €3k which includes boiler, pump, provision & installation of new twin-walled flue through roof area & making good. Zoning to space & water + 3 TRVs etc. a further €1.5k. Grants recoverable through seai - see their web page for details

Upgrading Boiler - do I need to clean out gas oil tank?

Problem solved. Tank needs to be fully emptied of gas oil (diesel) and sludge but thorough cleaning/scrubbing not necessary. Thanks all.

thanks.

smokey said:

Problem solved. Tank needs to be fully emptied of gas oil (diesel) and sludge but thorough cleaning/scrubbing not necessary. Thanks all.

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Smokey, did you just tip the tank over and drain the diesel? I'm looking to do the same thing very soon.

I reckon once I have it drained down by burning it off I'll be left with maybe 50 litres of gas oil. Could be less, I don't know, I'll have to do the maths. I take it I need to empty this out somehow, and clear the line to the existing boiler. I imagine even a slight mix wouldn't be good for a pristine new burner.

Smokey is it dangerous to use gas oil with a condensed boiler. I just had a new condensed boiler fitted last week. I rang our oil company today to top up with kerosene only to be told we have been using gas oil for the last few years. Can this damage our new boiler.

Your condenser will not run on gas-oil, it will be sooty, smokey and create lots of carbon monoxide, you MUST change to kero....your installer should have made you aware of this

DGOBS, We only have the condenser a week and it is working away fine, We have 9 rads working from it and so far no problems. Are you saying if we are using gas oil that it should not work at all. By the way we were not asked if we were using kero or gas when we had it installed, Also I specifically asked the oil company for kero on our first fill and apparently we were given gas oil since, I only realised this when I asked them yesterday. The tank is almost empty now so in your opinion would it be wise to run with it for a few days and then order the kero. From Smokeys post it looks like if sludge is a problem I am in trouble already. Will this damage my new condenser after having it for only a week.Thanks for your advice so far DGOBS, Regards, Salaried.

Salaried,

Remove all traces of diesel from tank. Do not mix the two fuels. Pump pressure for kerosene is much lower than that required for diesel, so when trying to burn diesel at lower pump pressure will result in diesel not completely broken up into tiny particles and therefore will not burn properly, resulting in sooting. It is a heavier fuel than kerosene.

Immediately remove all remaining diesel, clean inside of tank, remove all diesel from oil line, filter and oil pump in burner. Refill with kerosene, SERVICE and COMMISSION boiler and it should be fine. Do not continue to burn diesel.

Shane, our oil line is running under our extension, through our back and onto the tank. We have just put down new tiles in our extension and a new expensive patio out the back, How do I remove all diesel from our oil line. Seriously worried and sick of this guy right now, First he destroyed our kitchen and now this.

Use an oil suction pump, or a small air compressor to blow it through.

If oil line is going under floor of extension, make sure you do a pressure test on the line to ensure there are no leaks in the line.

A small amount of gas oil well diluted with kerosene will not cause any problems in your boiler. I have done this and you will not cause any harm to the burner or boiler.

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bstop said:

A small amount of gas oil well diluted with kerosene will not cause any problems in your boiler. I have done this and you will not cause any harm to the burner or boiler.

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First of all, it will depend on how much a small amount is. Cold weather can make diesel separate away from the kerosene and not burn correctly as diesel becomes heavier with cold weather.

Condensing boilers will come with an Enhanced nozzle, either EH or ES unless of course it is above 1.00 USGal. This is a much more finer nozzle than diesel nozzles such as S or H and requires at least 16bar pump pressure to force the diesel through, especially in cold weather. Normal nozzles will only require on average 12bar pressure for diesel. Condensing burners will come with a factory-set pump pressure on average of 8.5bar pressure, far too low to atomize diesel through an EH or ES nozzle.

By putting diesel through an ES or EH nozzle at low pump pressure, the following will likely happen:

1. No damage should occur to the flame chamber boiler walls (as long as not for prolonged period).
2. Due to incomplete combustion of un-atomized fuel, sooting of the boiler WILL occur, leading to inefficiency and ultimate lock out of the boiler.
3. As a direct result of incomplete combustion, damage or buckling of the baffles will likely occur.
4. Nullification of the manufacturer's boiler warranty.

For what it takes to remove, why not do so? If a job is worth doing, do it right in the first instance. Less down the line possible complications, call backs and ultimately less unhappy clients!

jeez lads, we're taking here about a domestic 10mm diameter oil supply pipe!! How much fuel are we taking about here!!
Approx, 10m x 3.14 x 0.005 x 0.005 x 1000 = 0.785litre.

Does the diesel in the oil tank not count?

I presume the diesel and sludge would have been removed.

Sorry, I thought bstop well diluted the gas oil with kerosene. I would have presumed he did this within the oil tank.

Remember from the bottom of an oil tank to the bottom of the outlet will be about 65 litres. This will not be used under normal usage and will be mixed.