UKH

Anybody with oil boiler wisdom in here.

Early June I bought a house with an oil fired central heating system fired by a boiler aged about 20.  It was working but very smelly.  Had it serviced, fully expected it to be condemned but it was allowed to continue.

It broke down shortly after, had oil pump replaced.  Was working ok and less stinky. Worked for about a fortnight then locked out again.  Engineer came back, said motor had seized and damaged new pump.  Replaced both - big bill.  Two days later it locked out again, engineer replaced photocell.

Broke again last weekend - had new boiler installed on Weds.  Damn thing failed to start again tonight, managed to get it going by pressing reset button but am now deeply suspicious something else is amiss.

Engineer did say my oil tank had water in bottom of it and put a sponge in bottom to soak up water.  Also that pipe was fully of black gunk that he had to blow out with a compressor.  I’m now concerned there might be a fuel virus or a blockage or something, but surely an oil tech qualified engineer should be checking stuff like that.

Any ideas or experiences?  Having already spent over 4k on this problem I feel sick.

If there was water in the tank at levels where it’s come through the feed line, it will be worth getting this sorted properly, not just a sponge but getting the tank pumped out and any water and gunk filtered from the oil before it’s put back in.  If the oil transfer line has had water running through it for some time it may be heavily sedimented in the inside and need replacing.  Both of these things are a lot cheaper than any of the work you’ve had done so far. 

There should be a filter bowl in the oil feed line (normally bear the tank), if water has got to the boiler then this will likely need servicing/replacing too. 

I guess the boiler engineer is only concerned with the boiler, the supply of fuel to the boiler is not his responsibility.

There might be sludge and sediment at the bottom of your tank as well as water, if there’s a significant amount of water in the tank it suggests that the tank hasn’t been cleaned out for many years, is it a plastic tank or an ancient metal one?

Thanks for the reply.  Engineer also said to me that my tank was likely porous and would need replaced soon and was on for doing it when the oil level had gone down another few inches.  Had never heard of tanks going porous and letting in water.  If I could get away with pumping out and filtering, that would be a bonus.  Replacing line not that easy as it’s buried.

plastic tank.  Probably never been cleaned.  Previous owner did zero maintenance of anything.

I’ve not heard of tanks going porous, the water in the bottom is usually due to condensation forming inside the tank, then running to the bottom. This then builds up over the years. 

Do you know how old the tank is? Sometimes they’ll have a sticker or a stamp on the top with the year. If it’s more than 15 years old and outside then it may be worth considering a new tank too. 

We had problems with the supply to ours. Turned out the flame valve(or whatever its called) outside the house had filled with gunk and was blocking the oil supply. Straightforward diy job to replace it.  Worth undoing the fuel line at the boiler then pumping fuel into a container. That'll show how much pressure you have and if there's any contamination. 

A friend was having similar issues with her oil boiler, the excess water in the tank was ruining the oil pump because water isn't a good lubricant.

She spent a fortune on new pumps and filters etc before finally giving up and getting a calor cylinder and gas boiler installed. 

Oddly she never had the tank emptied/cleaned/replaced.

If previous owners have generally managed it with a tank that's always quite low, the condensation will build faster, than if it was always kept at the half way mark or higher. Or perhaps the house was vacant at some point and tank left very low.

With any fuel tank (oil or vehicle) if left standing for while, it's best to leave them fully tanked to prevent condensation and rust. 

Hi Sealwife, sorry about your problems. You do not say the make of your boiler and it can help with your problem.   Mine is a Trianco that ive run for 32 years now,  1st you need a proper engineer. Porus tank and sponge in the bottom says all you need know about your "engineer". Mine collects water as they all do due to condensation and just requires a pipe down to the bottom and pump out the couple of gallons (10L) of water, takes 10 minutes every 5 years.  The main relay unit is usually what cause's the burner to fail to ignite. About £30 on ebay ive used 1 over the year's due to dirty contacts in the original.   The pumps hardly ever fail but the shut off valve that screws into the pump can suffer from "O" ring failure and will cause the unit to lock out  as the pump cannot raise the right pressure.  30 minutes and pence for the "O" ring.  Sorry to hear that you have spent that much but its a classic case of a engineer who hasn't a clue & and changing everything till he solves the problem and using your money.

Hi - boiler is a Warmflow and is four days old!   Engineer came again this morning, found water in fuel coming in to boiler and has hatched a plan involving a pump and containers and perhaps a separator.  

I had actually wondered why we aren’t just pumping the water out of the bottom but had thought it was because there is also sludge which needs to be removed.

Next question is - can you put kero in s container which once held red diesel, as I have access to a few of those?

Had a similar issue with our oil tank, turned out there was a small hole in the top where water was entering. Had to replace the oil pump and clean the line from the tank.

I bought a really cheap pump, (the sort that attaches to a drill), cable tied a hose pipe to a length of wood batten, (to push it right to the bottom of the tank), and ended up pumping out about 40 litres of water.

If you pump into an old bucket before transferring to a drum you can see when you start pumping oil from the bottom. The tank outlet is normally a inch or two above the tank bottom to allow for condensation water to accumulate. You need to get the oil/water interface as far below the outlet as possible, then remove and clean any filters, then run off some oil to check it's free of water contamination.

It's unlikely you do have any algae growth, but if you speak to your oil supplier they'll be able to suggest a suitable additive to deal with it. It's been over 5 years since I did the above and the boilers been fine.

EDIT. Re: containers in your last post, heating oil and diesel are very similar, the containers are fine, there's usually a waste oil tank at your local civic amenenity site for disposal.

Where abouts are you in the UK? 

Looking likely that I will have an 8 year old 1000l tank going spare soon, in Flintshire, North Wales, asthe village where my BTL (former home) is, is getting mains gas. 

Water in the system makes the pump seize up and often take the motor out as well. I've one in my back-up system that's done it. Not regularly replacing the burner jet is also death to the system.

It does indeed, but that much water will bring in the flame failure lock out and if the pump seize's the plastic drive from the motor will break as its meant to.

I did not know it was only 4 day's old.   You are going to have a problem. The  "engineer" is going to blame the tank and fuel supply and void any warranty. But the question for him is why did he not remove the water/sludge after it locked out the 1st time . That show's lack of knowledge of what is a very common fault.    

Knew I was pushing my luck with this, mine locked out tonight for the 1st this cold spell. Quick tap on the side of the pump and valve jumped in so it will need a clean tomorrow.

Thank you all so much for your assistance - you lot have been so helpful.  

I live in Orkney so, a little bit too far to take on your offer of a tank SAF.  I have now sourced some barrels locally and arranged to borrow a pump from someone locally who had the same problem.  Not sure how things will pan out with the engineer - I’m deeply my hacked off as he didn’t spot the problem with the old boiler, did spot it when he fitted the replacement a few days ago but still commissioned it.  I’m hoping it has locked out before knackering the pump, if not I will be pushing him hard to replace it at his cost.

Doubt I have time to get work done before next weekend but I will let you know the upshot.

Just the slightest trace is enough to do the pump in, you can't even see what's stopping it.