Oil burner service technique

[Paul]

Has anyone got instructions on how to service a boiler i.e what needs to be done?

Cleaning Parts that should be replaced What to expect? What colour the flame should be etc?

[Bob Minchin]

I once saw a Haynes manual on Oil boilers. It was no good to me so I passed it by but you might find one in a Public Library - remember those from pre-web days?

Bob

[Alec]

Pressure jet ? WallFlame? What type is it ? Rgds Alec

[pwhel]

It's a Bentone

Rgds

Paul

Alec wrote:

[Alec]

Hi Paul, the brand means nothing to me it's the method of burning the oil that determines how it should be serviced. If you have no combustion analysis tools then you are restricted to vacuuming it out, cleaning any baffles and checking for flue leaks. If you can see the flame then you can play with the air supply, but there should be no need to. Rgds Alec

[Peter Scott]

If the boiler seems to be functioning OK then all you really need to do is replace the jet once a year (about 5 pounds). Take the old one with you to get the right one or refer to the manual if you've got one. Jets are removed with a spanner and have normal thread. Don't bother to try to clean the old one. You normally have to remove the heavy chunk of machinery from the heating box to do this, after disconnecting all the wires. There will be two or three screws that lock down onto a largish pipe coming out of the back of the chunk. You should also gently pull out the optical sensor from the chunk and clean it with a cloth. It's easily broken.

Then whilst the chunk is out peer inside the heating box. Brush round and vacuum.

Main thing is not to alter any baffle settings. You can't do this without turning a screw but you might choose the wrong one to turn.

I'm not a pro but have been servicing my oil boiler for ten years after two close shaves with rip-off merchants. Things that go wrong are the oil pump packs up, usually leaking oil and giving poor ignition, or the ignitor transformer packs up, or its wires decay (they are just like spark plug leads), and the thing just won't start up. In the latter case you will get a lockout light come on.

I was astonished how easy and primitive it all was. Don't be afraid! Of course I only know one model- a Myson Velaire, but the parts all seem to be standard so I guess the boilers don't vary that much?

If you've got said machine I could send copies of manual pages.

Email to peter at peter hyphen scott dot org dot uk

Peter Scott

[Michael Chare]

In addition, assuming that you have a pressure jet boiler:

Whiltst there are many makes of boilers, there are far fewer makes of burners.

You should check the position of the electrodes. For that you need to know what the correct position should be.

A pressure gauge to check the oil pressure is not expensive say £20. Useful if you are replacing the pump.

If the oil tank has a filter with a replacement element you should change that! Otherwise the filter will eventually clog up. (About 10 years in my experience!)

Typically boiler manufacturers will send you an installation manual which will include servicing instructions foc.

[John]

"Michael Chare" wrote in message news: [e-mail]...

SNIP some good and some poor advice

There are a number of variants with minor variations but assuming you are asking about a reasonably new boiler with a pressure jet burner try the following.

Have available a vacuum cleaner with hose attachments, A long stiff bristled flue brush, a soft straight brush such as a clean 1" paint brush, Screwdrivers, spanners, allen keys, scraper, replacement nozzle, replacement filter element and joint, every three/four years a new flexible oil hose, combustion analyser kit preferably Briggon or Fyrite chemical type as oil fumes tend to poison oxygen cells in electronic analysers.

Switch off and allow to cool unless you like working with burnt fingers.

Ensure isolation of the boiler from the power supply. time clocks and thermostats can and do switch on while you are working

Shut the oil service valve which should be local to the boiler.

Put down a good sizeable dust sheet

Remove the casing door and if a top entry flueway type the lid also, thus revealing the boiler shell and burner.

Remove the flueway access door to reveal the flueways and removable baffles (retarders)

Judge the amount of soot/dust within and use vacuum cleaner as required, removing the retarders in turn and remembering the position and orientation of them for ultimate replacement. Once all retarders are out brush or scrape the interior of the heat exchanger clean. Loose dust or soot can slow the rate of transfer of heat from the flue gases into the waterways and reduce the efficiency significantly, costing you money and passing your hard earned heat out into the open air.

When you are satisfied the retarders and the chamber interior is clean locate the securing nut(s) or clamping screws which hold the burner in place and withdraw it from the boiler. There are a number of basic types of pressure jet burner and bear in mind that yours may be different in some respects from what I describe here. If I knew what you actually had it would be easier but I describe here the procedure for a Riello burner which has a sequence control/ignition (grey) box mounted on top of the burner unit. As viewed from the rear (non firing end), on the left hand side is the oil pump with one or occasionally two oil hoses (suction and excess return pipes). You will see a dark coloured protruding screw with a slotted end. DO NOT ALTER THIS SCREW it is the oil pressure setting screw and you will have to set up the whole burner from scratch if you do. Below the setting screw is a hexagonal headed plug which is a pressure test point. Checking of the oil pressure on a satisfactorily running boiler is not normally neccessary unless you are commissioning the unit or fitting a replacement pump in which case it should be used to set the pressure to manufacturers specification. On the right hand side you will see the fan casing and on some variants a hydraulic ram operating a flap which closes off the air intake when the burner is not running. Early (long ram) models used a screw and locknut on the ram to set the open position as an air inlet adjustment, later models used a shorter ram with fixed travel and a rotating mask to adjust the air. Both of these types of adjuster should not be moved unless you have reason to do so. Once set they should remain constant. Remove the fan casing, being careful not to damage the oil line to the ram if one is present and expose the fan. Use a brush and possibly a small scraper such as a screwdriver (carefully) blade to clean off the fan blades. A significant amount of fluff and dust can often be found here. Brush clean the fan casing and inlet airway then refit the casing to protect the fan. Turn to the front (flame end) of the burner and locate the screws which hold the blast tube in place. Undo these and draw the blast tube off the front of the burner to reveal the nozzle, electrodes and mount. The elctrode position with relation to the front of the nozzle should be carefully noted for accurate replacement. Locate the electrode securing screw and loosen it to withdraw the electrode mounting (porcelain) block. Clean the elctrodes asembly (it should look like new when you have finished) check its gap (about three to four mm) and put safe to one side. Clean away any dust, soot or other junk from within the space but do not damage the face of the photocell which is at the rear of the chamber With two spanners undo the nozzle and withdraw it. Stamped on the flats are details of the size (0.50 USGPH or similar info), spray angle (60 or 80 degrees usually) and spray pattern code (S, H, W etc) Replace with new nozzle of same spec. Reassemble taking care to ensure the electrode clearance(s) are as you found them, refit the blast tube and turn to the grey box. On the left hand side is a clamping screw which should be loosened and the box withdrawn (unplugged) from its seat. The photocell is mounted (plugged in) to the front of this box and it should be cleaned with a soft brush. Check for loose wires in the fixed base of the grey unit and replace it. Replace the burner into the boiler and refit the mounting screw/nut. Turn on the oil service velve and check very carefully for leaks in the oil hoses. These are rubber under the braid and they become brittle. The movement associated with servicing is often enough to crack the rubber and start a leak which is why they should be replaced regularly. Go out to the oil tank and locate the oil filter. Turn off the tank valve (and sight gauge tube if fitted) and remove the filter. Run a little oil through into a clear jar and inspect for water/dirt in the tank Clean if of the strainer type or replace if a paper element. Refit and turn oil back on. Vent or purge the air from the filter bowl. If there is a drain valve at the back of the tank run a little into the jar and check for water. Decant any water present off. Inspect the tank for corrosion Go back inside replace/restore all inner parts and casing doors and power up the unit. Run on test and when warmed up draw from the sampling point a smoke sample (should be 0 or 1 on Baccarach scale). Draw a sample of flue gases from the sample point into the analyser and check CO2 levels (depending on boiler but expect between 9 and 12 %) If all OK put temperature probe into sample hole and take flue gas temperature having allowed to stabilise. New boilers with high eficiency will show around 200 degrees C, older ones could be anywhere up to 450 which gives an idea of how much heat they wasted! If readings are not satisfactory you may need to tweak the air setting slightly but do not make any big adjustments and mark where you started from. When satisfied record figures and comments preferably on a history card you keep with the boiler Refit sample plug and outer casing, wash hands and put kettle on.

HTH

John