So I was ambling across the garden the other night with my latest ebay mega-lumen Cree LED retina blaster and decided to shine it into the oil tank. The level was not far off the top of the feed outlet so I got on the phone and ordered 500L of heating oil to keep us going til next winter.

The delivery came today and my GF put the CH back on straight afterwards. An hour or so later the driver came back and said he’d made a mistake and filled the tank with red diesel. CH was then turned off immediately.

The oil company are sending some contractors in today to drain the tank (and hopefully the 8 metres of feed pipe to the boiler) However, I suspect that they’ll have to tip the tank to get the last of the current contents out. I really don’t want them to do this as space is tight around the outlet pipe and I don’t want any strain put on the feed pipe or filter ‘cos 500L of the replacement heating oil under the house would be more than slightly inconvenient than a misdelivery of red diesel.

So, if they sucked as much of the contents out of the tank as possible without tipping it, how would our Worcester Bosch Heatslave 20/25 react to burning 500 litres of heating oil with a few litres of red diesel in the mix?

Cheers 🙂

If they drain the tank & refill, then drain a few litres from the boiler end to ensure the new fuel is bled through to the burner then minimal problems.
How long did the boiler run until turned off?
The red will not burn correctly & will soot up the flame chamber in a few days, this will cause incorrect combustion & could lead to carbon monoxide levels rising.
I’d be insisting they service the boiler & then check the CO levels in a few weeks to ensure is operating correctly.

the feed pipe would be disconnected to tip the tank I would have thought.

Is it a metal or plastic tank? If metal it will have a sludge cock on it that is lower than the outlet anyway so no problems.

They may suck it out from the top so no problem there.

Oil line bleed at boiler end until correct oil comes through, but wouldn’t be a bad idea to ask them to service it in a weeks time just to be sure.

And oil boilers when they soot up like that will turn themselves off.

How long did the boiler run until turned off?

About an hour so it’s possible that only the kerosene that was in the feed pipe went into the boiler.

The red will not burn correctly & will soot up the flame chamber in a few days, this will cause incorrect combustion & could lead to carbon monoxide levels rising.

Is that if the boiler was burning pure red diesel or a mix that only had a small amount of diesel in it?

They may suck it out from the top so no problem there.

Hopefuly, although I’ve pumped the tank contents out in the past so a plumber could replace a corroded filter and put an elbow joint in the feed pipe bend and, although I only had to empty it to just below the outlet, it got tricky towards the bottom of the tank.

the feed pipe would be disconnected to tip the tank I would have thought.

Didn’t think of that. Will make sure that’s done if necessary. Cheers.:-) Hope the contractors aren’t fatties though ‘cos it’s not exactly the most accessible feedpipe/outlet interface in the universe.

Will insist on a service I think.

I’d also be wanting a written statement of exactly how they managed to screw up…, as our Suppliers aren’t multi-fuel tankers, are they?

Tankers have multiple compartments and sometimes carry different fuels I believe.

Wouldn’t the red diesel sit on top of the heating oil?

We’ve done work like this before for Total. We send our one of our little vac tankers and suck the tank out. You can pretty much get the whole tank out, maybe just a liter or two left (if you don’t tip). They cannot do this as their tankers don’t a suck option.

Quite a few suppliers run about in multi pot tankers. Saves them on transport until something like this happens.

Ok, happy to be corrected.

Get the fuel line bled/emptied and have a new jet fitted on the boiler. Although similar I think diesel is a different viscosity and won’t pump nicely (by the boiler).