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Discuss Worcester Bosch Greenstar Heatslave Boiler Smell. in the Oil and Solid Fuel Forum area at PlumbersForums.net

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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.
 
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Possible cracked nozzle assembly/high pressure line. Hard to say without looking at it. Was the pump replaced? If the smell only occurs during firing and no signs of leaks I would first look downstream of the solenoid.
 
Possible cracked nozzle assembly/high pressure line. Hard to say without looking at it. Was the pump replaced? If the smell only occurs during firing and no signs of leaks I would first look downstream of the solenoid.
Many thanks for reply, yes a new pump was fitted with the new burner.
 
Ouch! Lot of work for an oil smell.
Normally an oil smell after a refill would be a leaking seal on fuel pump. Either the shaft seal, the adjuster seal or the seal on the fuel stem which drops fuel into bottom of boiler.
All easy fixed without a new burner.
Then if they're dry its checking any joints and any fusible head fire valves that will leak if you look at them funny.

Blue tissue is your friend with a leak. Very easy to spot.

You may want to seek the services of a different oil engineer. In my honest opinion you've spent a lot of money that you really shouldn't have.
 
Frightening!!

Isn't it just mate? All that work and money on a new burner for an apparant oil leak. Next port of call is hire a different engineer who knows what they're doing.
If no viable leaks and a new burner then I'd be looking at possible failed seals, combustion chamber seal, burner flange seal.
 
Ouch! Lot of work for an oil smell.
Normally an oil smell after a refill would be a leaking seal on fuel pump. Either the shaft seal, the adjuster seal or the seal on the fuel stem which drops fuel into bottom of boiler.
All easy fixed without a new burner.
Then if they're dry its checking any joints and any fusible head fire valves that will leak if you look at them funny.

Blue tissue is your friend with a leak. Very easy to spot.

You may want to seek the services of a different oil engineer. In my honest opinion you've spent a lot of money that you really shouldn't have.
I agree it is a lot of money but you can only go with advice given. If it was an oil leak wouldn't the smell be there all the time?
 
I agree it is a lot of money but you can only go with advice given. If it was an oil leak wouldn't the smell be there all the time?
Not necessarily. Parts of the burner workings only have oil in them when it's running. Plus when it's running it's hot and will emphasise even the slightest leak.
 
Are you sure its a neat oil smell and not a smell of products of combustion when the burner is firing?
 
Isn't it just mate? All that work and money on a new burner for an apparant oil leak. Next port of call is hire a different engineer who knows what they're doing.
If no viable leaks and a new burner then I'd be looking at possible failed seals, combustion chamber seal, burner flange seal.
Thanks for your reply. Your advice re failed seals etc will be looked into. Thanks again.
 
Are you sure its a neat oil smell and not a smell of products of combustion when the burner is firing?
Don't think it is a neat oil smell because it is just as strong from the outlet flue. We could smell it from the other side of the garden but only when the boiler was firing.
 
Don't think it is a neat oil smell because it is just as strong from the outlet flue. We could smell it from the other side of the garden but only when the boiler was firing.

That right there suggests a smell of products of combustion. You need to isolate the boiler and have a decent engineer investigate promptly.
 
The new burner has not been set up properly.
Hi Simon, the problem is the smell was there before the new burner/pump was fitted, this was supposed to fix the problem, so I can only think there is another problem causing the smell. Hope this makes sense. The boiler is Worcester Bosch 12/18 condensing combination, floor standing, conventional flue and room sealed flue. Part of the problem seems to be its not room sealed. Many thanks for your reply.
 
So a conventional flue or a room sealed balanced flue? The two are completely different. Perhaps a picture of the boiler?
 
Ok. Could you take the front cover off the boiler and take a picture and upload it maybe?
Balanced flues can cause this issue if certain problems arise, I dont think it one of the above but let's rule it out.
 
Ok. Could you take the front cover off the boiler and take a picture and upload it maybe?
Balanced flues can cause this issue if certain problems arise, I dont think it one of the above but let's rule it out.
Taken photos hope they help. Just to add some detail, No cold water tank in attic or anywhere else and no hot water storage tank other than what's in the boiler itself. These were taken out when the boiler was fitted approx 10 years ago. Got to thank you for taking the trouble with your help.
 

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Oh, a horrible downfiring whoopsy. Hard to make out my thoughts from the pictures. You need to find a decent engineer now, someone more qualified than the previous, if you could even call them an engineer. You could go on the OFTEC website and search for a qualified engineer in your area to come visit, alternatively if you give me your location in the country I will check with my network of associates and see if I can find someone to attend. It really is hard to say what it is at the moment, however I suggest placing a carbon monoxide detector near the boiler. If it is products of combustion you're smelling this will warn you of risks.
 
Oh, a horrible downfiring whoopsy. Hard to make out my thoughts from the pictures. You need to find a decent engineer now, someone more qualified than the previous, if you could even call them an engineer. You could go on the OFTEC website and search for a qualified engineer in your area to come visit, alternatively if you give me your location in the country I will check with my network of associates and see if I can find someone to attend. It really is hard to say what it is at the moment, however I suggest placing a carbon monoxide detector near the boiler. If it is products of combustion you're smelling this will warn you of risks.
Hi, you can imagine how I feel after spending so much but still having the same problem. I have a carbon monoxide detector fitted almost as soon as the problem arose and it is showing all clear. I'm in North Wales near Ruthin. Again many thanks for taking the trouble to look into this for me.
 
Hi, you can imagine how I feel after spending so much but still having the same problem. I have a carbon monoxide detector fitted almost as soon as the problem arose and it is showing all clear. I'm in North Wales near Ruthin. Again many thanks for taking the trouble to look into this for me.

Ok. Give me some time to try and find someone for you please.
 
I've searched for some people in your area and I have a couple popping up. Try Lee Cuthill Cascade Heating on 07508 949540. Give him a bell tomorrow and see what comes of it. Failing that I might have another.
 
I've searched for some people in your area and I have a couple popping up. Try Lee Cuthill Cascade Heating on 07508 949540. Give him a bell tomorrow and see what comes of it. Failing that I might have another.
Things got worse then got a lot better. This morning got up to find no hot water, boiler not firing but could hear pump working. Reset button flashing red???? Called the engineer who came out right away. Spent a couple of hours stripping the boiler down and replacing seals and burner nozzle, all working fine now, smell has gone and boiler working A1. Just like to thank everyone who took the time to give me their advice, well worth joining this forum.
 
Things got worse then got a lot better. This morning got up to find no hot water, boiler not firing but could hear pump working. Reset button flashing red???? Called the engineer who came out right away. Spent a couple of hours stripping the boiler down and replacing seals and burner nozzle, all working fine now, smell has gone and boiler working A1. Just like to thank everyone who took the time to give me their advice, well worth joining this forum.

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

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