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