Heatslave 20/25 surge

[richard3009]

Just going to get an oil boiler tech to come out and give it a full check from top to bottom. Flue is straight out the back through the wall, 12 inches at most

 

[SJB060685]

Ok. Can you update us on what the problem is if you find it, it might be something I've overlooked or forgotten

 

[richard3009]

I've had a really good listen to it for 10 minutes definitely the oil pump in waves, another thing when it starts up it takes around 30 seconds for it to start whining, enough time to draw a vacuum in a 20 meter supply line, I'm leaning toward restricted flow making the pump work really hard, but not enough to lock out the bolier

 

[SJB060685]

I'm impressed at your knowledge Richard, few people have your understanding as a general homeowner. Like I said above vacuum gauge, the longer the line, the more valves, bends and restrictions etc all increases resistance which all add up. Running a few litres off at burner is also a good way of determining flow. Remember the average domestic oil boiler only burns a couple litres of fuel an hour, so if you were to draw 5 without restriction then that's a sign it's all good.

 

[richard3009]

In the event of restricted flow would it be easier to simply install a new fuel line, or are there good clearing methods. Lines cheap enough.
[automerge]1575972423[/automerge]
Also need to check the fire valve, are they all operated by the method push button to close manually and pull to reset open

 

[SJB060685]

These are supposed to be very good. Not tried one myself but know a lot of oil guys swear by it. Running a new line is not as straightforward as you might think. You would need a strainer at tank, a isolating valve before inline filter and fire valve, all of which will be ideally bushed together rather than a load of fittings and ideally a new burner hose, which I’m sure you’re aware is installed inside boiler casing. If someone was to run a new line then it’s either compression fittings with pipe inserts or flared fittings, NO soldered joints allowed.
I believe some older types of fire valve are wheel head but these have an internal metal fuse that once melt its new valve time. KBB is what we always used as you know these are a simple push back in to reset.

 

[richard3009]

Think we're ahead of the game here, I'm suspecting a fully gunked up acrylic filter in the Teddington valve wash out and away. With it being borderline restriction I just get the feeling that's my culprit, trouble is I have no daylight until Saturday, shall upload photos of a five year unserviced filter.

 

[SJB060685]

If theres a blockage anywhere downstream of the tank I'd expect it to be in the narrowest part of line, ie valves. If you're going to check check everything and obviously don't wash out with water, use neat kerosene from tank.

 

[richard3009]

Just one point after the bowl has been removed off the underside of the valve filter rinsed with clean kerosene, I assume you fill the bowl with it slightly not sealed to purge the air or is there a bleed screw on them, I don't want to sort all that air at the boiler end. Only three tight points on the system tank valve, fire stop valve and boiler flex valve, the horrible bulkhead 90 is long gone.

 

[SJB060685]

Some filters have bleed screws on them. Alternatively crack the compression fittings slightly. Always bleed at pump as well

 

[richard3009]

There is a fibre washer on the underside best be armed with a replacement too.

 

[SJB060685]

Always have replacement seals yes, o rings, washers, olives etc whatever you're working on

 

[Best]

I wonder are all the valves turned on plenty of turns, including the valve at tank?
Also oil hose not kinked in?
Either of those can cause problem you describe.
But the fact the oil filter hasn’t been checked means it is pointless to speculate until that is cleaned.
Alarming that your service engineer didn’t check that when replacing oil pump and at services.

 

[richard3009]

Just ordered an identical tank valve so I can simply swap the filter inside and stick on a fresh seal, it has to be well sludged in so many years, both valves are levers and fully open

 

[SJB060685]

Replace that strainer/filter at tank and check everything else downstream as well. Like best said above this should all be checked and replaced during routine servicing, perhaps it's time to find a decent engineer.

 

[richard3009]

Not possible to change anything upstream of the tank valve surely with 1200 litres sat there

 

[SJB060685]

You can replace the strainer/filter at tank no problem but to change the whole valve you would have to wait until oil runs out. I've known some snatch it with a little oil in tank but not 1200 litres, insurance companies could go mad and if you were to lose that amount of oil the environment agency would hold you accountable and that's a hefty clean up fee.

 

[richard3009]

Ok just the filter/strainer in the valve bowl, yep that's what I'm doing, wow I could just image releasing a 1200 litre head of kerosene, Christ that would have me in a slight tizz

 

[SJB060685]

Like I said it's worth finding a decent engineer, a good engineer is for life. You being an electrician means you have got a good grasp of things already however unless you have FGA, pressure gauges and a smoke pump etc then what you can safely and efficiently do is limited

 

[richard3009]

Sat having my tea tonight and can hear the oil pump is get more and more distressed, I was thinking to myself any minute now that's going into lock out and it did. So now I've nothing to lose I'm having that filter off to look torch in hand absolutely persisting it down, tank valve closed, cracked it open clean as a whistle I mean spotless fuel in bowl a few grains but nothing serious. Opened the tank valve and flushed the main outlet into a bucket a good litre. Refitted the filter bowl and bled off the air valve opened. Back at boiler closed flex valve and uncoupled from pump, open valve zero flow, popped outside to check the fire valve pressed the reset and it clicked hmmmmmm, back inside no flow, desperation gob around fuel line blow hard release and fuel flows slow but we have fuel, Couple line back up and reset lockout. Open bleed air bolt and she bubbles for 10 secs then pure high pressure fuel. It's been running as sweet as a nut for the past hour. Either fire valve or I was airlocked. All I can taste is kerosene small price to pay, happy days.