Domestic heating oil tank blockage

[Bruno]

Hi all,

For the last few years, I've noticed that my boiler begins to lock-out when there's higher and higher levels of oil in the storage tank. IOW, the heating system cuts out now when the level of oil in the outside tank is at about 11" deep, whereas a year ago, it would cut out when it was 9" deep and so on. I think when I first moved in here there was only about 4 or 5" of oil remaining before the boiler would cut off. So it's getting progressively worse. Refilling the tank 'cures' the problem (presumably because the increased weight of the oil creates enough pressure to force its way into the boiler supply pipe) and things are fine for a few months until the level drops too low again. Has anyone encountered this problem and if so, what's the cause of it and how can it be fixed? It's one of those dark green plastic tanks, BTW.

Ta.

[The Natural Philosopher]

generally by replacing one or more of the fuel filters ...

[Dave Liquorice]

Or removing any gunk that has got to the fire valve blocking the orfices there.

[snot]

As TNP says, you have a partly blocked filter. You'll need to drain and clean the tank otherwise it'll clog up again And probably replace all the piping and (fire) valves. Dave

[JimK]

/As TNP says, you have a partly blocked filter. You'll need to drain and clean the tank otherwise it'll clog up again And probably replace all the piping and (fire) valves. Dave /q

Drama Dave?!

I'm sure new filters will sort this for a worthwhile period of time for the op...

Jim K

[Michael Chare]

As I have found out! These days I change the Crossland paper elements every couple of years. I have isolating valves which makes this easy.

[snot]

Yea yea yea ----- mighty drama.......... yawn.. Tank needs checking to see where the crap that's blocking the filter came from. Obvious really

[JimK]

/- show quoted text - Yea yea yea ----- mighty drama.......... yawn.. Tank needs checking to see where the crap that's blocking the filter came from. Obvious really

- show quoted text -/q

I'd look at the old filters to work that out but hey who knows:-)

Have you got oil fired heating?

Jim K

[The Natural Philosopher]

well actually te filters are there because any tank will always have a bit of water and sludge accumulate in it.

You don't need to find out where it came from. Just replace the filter and wait another 20 years

[snot]

Yes

[snot]

Is the correct and sensible answer

[JimK]

/> You don't need to find out where it came from. Just replace the filter

Is the correct and sensible answer/q

We learn something new every day.

Jim K

[Dave Liquorice]

filter

Well the crap is only going to come from the tank so unless the water level has got up to the take off point it's not worth worrying about.

Will the filter catch the water? Water, low point in exterior oil line and a period of frosts make for a slush plug the feed and no oil at the boiler. BTDTGTTS in 10" of snow and -5 C dismantling the feed line and pulling a cloth plug through to clear the ice and crap...

There is now a glass bowl filter at the tank to trap any water/crap that comes out of the tank before it gets into the feed line. Glass so it's easy to check.

[Bruno]

Yes, oil fired heating and this is a 1200 litre rigid plastic tank that supplies the boiler.

I think there's something amiss, because the tank's outflow pipe is right at the base of the tank from what I can see, not a few inches above as some have suggested it ought to be. Plus there's no tap at the other end to drain off accumulated water. Neither can I see any filter housing in the line before it goes under the driveway on its way to the house. I'm guessing its not up the latest standards, although it looks modern enough and appears in good condition. Tomorrow when the daylight returns I'll take some pictures....

[Dave Liquorice]

Ours is very low maybe an inch, two at the most. You don't want it to far up as that is oil you can't get at. Well not without adding water...

Ours has no tank water drain(*) and didn't have a filter at the tank until after the frozen line incident. It does have a valve in the line at the tank but the sight glass (post line valve) has a manual lever rather than a "push to read, auto off" button.

Installed about 20 years ago by the previous house owners using Shell cowboys (fire valve inside, "gas only" twin wall flue, plus other niggles).

So does ours but it's been there 20 years and as installed probably failed the then regulations... Modern standards would actually give us a bit of problem as there isn't really a sensible place to put it that isn't too close to a window or a very long and convoluted oil feed route. Modern would also have to have a built in bund.

(*) I wouldn't fit one, something to fail, at the bottom of the tank... Yes water does accumulate but if the take off is an inch or so up it takes years to be come a problem, is easy to test for (dip stick and special gunge) and syphon out. A glass bowl filter at the tank will trap water and if it starts to trap a lot, time to syphon the tank.

[Bruno]

Started new thread with link to pictures....

[RobertL]

You can get "water absorber on a rope". It's used for getting water out of boat diesel tanks. You drop it in,; it sinks to the bottom and absorbs water. You pull it out a day later and throw it away.

Robert

[johnjessop46]

Flue manufacturers did at one time allow "gas" twin wall flue to be used fo r kerosene fueled pressure jet boilers with low flue gas temperatures. Firestop valves were "preferred" outside the point of entry to the building but for boiler swaps with the oil pipe emerging from a solid floor adjacen t to the boiler, indoor firestop valves were permitted. Current firestop va lves should be the type with remote sensor bulb positioned above the burner or in a position determined by the boiler manufacturer (often a clip is pr ovided within the boiler casing)

[Dave Liquorice]

Oil pipe comes through wall in 1" black plastic pipe as sleeve. Pipe is accessable outside. So no excuse other than having to drill a hole for a sleeve to get the bulb and capillary tube through.

The old one was a capillary type. Fitted a new one outside a year or so back. Boiler too old to have clip for the bulb...