Worcester Bosch Greenstar Heatslave Boiler Smell.

[Darranj]

Hello, this is my first time on the forum. Three months ago we had a 1000 lt fill. We then noticed a strong oil smell when the boiler was firing up. There was no sign of an oil spill. Contacted our engineer to have the boiler serviced, still the strong oil smell was there. Recommended having new Burner/ pump unit fitted, Still strong oil smell. Advised having the Tiger Loop renewed and refitted outside, still strong oil smell. Advised having a vent fitted on the outside wall, still strong oil smell. Have had all filters renewed. Additive was added to oil tank. The smell only occurs when the boiler is firing, and clears soon after the boiler stops. Can anyone offer any advice on what to do next Please. Had a Carbon Monoxide monitor fitted and shows all clear. My real worry is the oil smell is inside the house as well as outside from the flue.

Just an obvious question but did the engineer commission the new burner as what your describing of the smell only occurs when it’s firing. The co2% should be 12-12.5% I’ve had customers report of oil smells and it’s simply that the boiler hasn’t been commissioned properly. Your co2 meter won’t go off if the boiler is slightly running rich or lean as it won’t produce enough co to trigger the alarm however the incomplete combustion will leave a nasty smell/taste in the air. Just in case your “engineer” doesn’t realise!! they need to set oil pump pressure first then adjust air damper to get the co2% with an analyser to recommend settings that will then ensure you have a clean burn and therefore no smell.

 

[SimonG]

Co2 shouldn't be 12.5, need to consider age of boiler, flue and outside conditions. If it's on a bench in a factory you might get away with 12.5 but not in real life conditions.

 

[SJB060685]

Simon I completely agree. Each boiler is different, CO2 % will vary on individual boiler and flueing conditions. On older boilers you'd be looking at closer 10.5 - 11%, you can get away with more on modern boilers based on burner efficiency and boiler/flue construction. Let's not forget though that the CO2 should always be adjusted to ambient air temperature. If its-5°c outside your CO2 should be adjusted to a lower value, so when the air is warmer and less dense in the summer it's CO2 should coincide with a cleaner burn.

 

[wqucte]

So seals had failed? What was the problem for burner in lockout mode?

Also going back to your early posts the tiger loop should be outside - it will definitely smell if inside. Did one of these guys relocate the tiger loop outside - reckon that is the root cause and all of the rest was a waste of time and money.

 

[Darranj]

Many thanks for reply, yes a new pump was fitted with the new burner.

If your sure the smell only occurs when it’s firing and there’s no leak then the most likely cause of the smell of in burnt fuel is a poorly setup burner. If your engineer is unaware of how to set it up you’ll need to find one that does. 1st step is to setup oil pump pressure on the riello burner I think yours is something like 115psi but the manual will tell you! Once that has been done you’ll need to correctly setup co2 percentage which is either 12% or 12.5% but again manual will tell you percentage required. The engineer will need an upto date flue gas analyser which is capable of going oil and a set of Allen keys. Once you’ve got that setup you’ll then need to do a smoke test if your engineer is oftec he’ll have one of these machines five pumps with the paper in it and you should have a zero result. Frankly if your engineer hasn’t done any of these above steps he/she doesn’t sound qualified and you’ll need to find an oftec engineer. If they have done these steps then I’d firstly service the boiler again as in remove all the baffles and give the boiler a bloody good clean internally. I’d also change the fuel nozzle as these can fail and cause setup issues. You can also check flue integrity with FGA to make sure products of combustion aren’t mixing with air for combustion as this can cause boiler to burn inefficiently. If all of these points are done then I’m afraid if you can still smell products of combustion then you might think about moving the boiler outside.