Greenstar Utility 32/50

[Millsy 82]

I got called out today to this boiler which kept going to lockout apparently the last tenant ran out of oil the landlord had it topped up new tenants have been in for a week and the boiler wasnt working. I thought great pull some oil through fire it up and test pressures smoke fga etc.

So pulled oil through went to fire it up explosive ignition ran for 3-5 secs started to vibrate like mad so I knew it wasnt right pressure was fine and not bouncing up and down so no air and filters were clear. Next I thought it was choked up checked combustion chamber not really dirty not enough to cause that anyway.

Asked have you got the manual (Of course they didnt that would make life far too easy) and it was to late to call tech so I looked at the air setting it was set at 16 I thought to myself most worcesters are around 3-4 I will try reducing it a bit so dropped it down to 10 and tried again explosive ignition gone but it ran then went to lock out sparking constantly so I checked photocell ran constantly so photocell fine its just not set up right.

Dropped air to around 4 ran fine checked smoking quite a bit so up to 6 when it stopped smoking so checked CO2 which was at 15% they are usually around 12% so I thought I would set it up around that the closest I could get was 12.9% otherwise it would not run it still drops out every now and then about 15mins.

So at the moment it is set up
CO2% is at 12.9 Should be 12.0
CO 8ppm
Ratio 0.0001
Smoke 0

The only thing I didnt check was the nozzle as I know I didnt have anything anywhere near it 1.10 45 S. So I am thinking the nozzle is completely the wrong size but by that time everything was red hot and it was 7 o clock. So going back with correct nozzle and servicing it whilst I am there.

So after all that my question is only short.

How has this boiler been working since November last year when it was last serviced. My only thought is somebody has been tinkering. Or different oil.

 

[Dotty]

Check they're running kerosene, pump pressure would be 8bar. I'd actually be looking for 11-11.5% CO2.

If it was running 35sec the boiler would've been full of soot.

 

[dontknowitall]

Thank you, Croppie, for that. I don't know what it is about boilers and me but when I read questions like that I have no idea. Then I read an answer like your's and think, "I should have known all that".

Then I go to a boiler that's broken down.

And panic.

But an hour or two later, suddenly I've found the problem and fixed it.

I suppose that's the important part, but it still amazes me that I just can't see through the problem when people post a question here.

Just reading the above I must have been on the ribena again.

 

[Dotty]

No one knows everything (except Gasman!) but everyone knows someone who knows something. I'll pm you my number DK. I get stuck too!

 

[Millsy 82]

Check they're running kerosene, pump pressure would be 8bar. I'd actually be looking for 11-11.5% CO2.

If it was running 35sec the boiler would've been full of soot.

Pump pressure was 120 PSI which is around 8 Bar. Asked the tenant if he had delivery ticket but as landlord got the oil there was no ticket around. Is there anything else I can do to make sure it is kerosene I have always gone by my checks. I have only ever worked on small boilers I always thought 35sec was more commercial.

I only thought 12% as most of the worcesters I have worked on have been around that but out of curiosity why would you be looking for 11-11.5%.

I passed my oil about a year ago but dont work on them enough so still really trying to find my feet the boilers themselves are easier than gas but when it comes to the burners never really worked on them before hand and like the acs they dont really teach fault finding skills I suppose thats why it took me 2hrs.

 

[Dotty]

35sec is mainly used on commercial but you will come across it on your travels sooner or later. You'd be looking 12bar there. I go for 11-11.5% because that's what the majority of the manufacturers specify. It gives you a cleaner burn, a less bumpy start and is more fuel efficient.

 

[SimonG]

I wouldn't set anything at 12%. Unless you want to be going back to clean it out at some point. I'm always a happy bunny at 11 - 11.5%.

I think that one is HE. If so it won't run on 35sec, it's in the worcester manual for all the he's. Come across that a couple of years ago on a farm. New install, red in the tank and no settings in the book for red so phoned worcester 'Oh no you can't run the new ones on 35sec'.

 

[Dotty]

I wouldn't set anything at 12%. Unless you want to be going back to clean it out at some point. I'm always a happy bunny at 11 - 11.5%.

I think that one is HE. If so it won't run on 35sec, it's in the worcester manual for all the he's. Come across that a couple of years ago on a farm. New install, red in the tank and no settings in the book for red so phoned worcester 'Oh no you can't run the new ones on 35sec'.

I've spent a happy couple of hours too cleaning thick oily crap out of an HE warmflow after a farmer ran 35 sec through it.

 

[Best]

12% co2, if a manufacturer specifies around that, might be okay if the boiler has a good drawing tallish flue pipe, but some flue pipes are prone to downdrafts or poor draw at times & low level flues have no suction so risky as everyone said to fine set burners.
35sec (diesel) is red in colour if you look at some you have run into a jar. If it wasn't, - we would all be using it for our vehicles! :grin:

 

[Roger Welton]

I also hate the smell (and taste!) of 35sec have to clear any off the van pronto.

 

[Millsy 82]

I wouldn't set anything at 12%. Unless you want to be going back to clean it out at some point. I'm always a happy bunny at 11 - 11.5%.

I think that one is HE. If so it won't run on 35sec, it's in the worcester manual for all the he's. Come across that a couple of years ago on a farm. New install, red in the tank and no settings in the book for red so phoned worcester 'Oh no you can't run the new ones on 35sec'.

I have always set them from MI's if I dont have that I call tech for either the boiler or burner if I cant get that say if its too late I set them up off my smoke pump at around 11-12% then go back next day with all the info on them.

Are you saying the MI's are more guidelines even if they say 12% you put them at 11-11.5%.

 

[Dotty]

There are far more factors affecting clean and efficient combustion on oil than there are on gas Millsy, Next boiler you go to, if you have the time, set her at 12%, then after a few starts back her off to 11.5%, listen to how much smoother she starts, and then compare your CO/CO2 ratios.

 

[Millsy 82]

There are far more factors affecting clean and efficient combustion on oil than there are on gas Millsy, Next boiler you go to, if you have the time, set her at 12%, then after a few starts back her off to 11.5%, listen to how much smoother she starts, and then compare your CO/CO2 ratios.

Went to another oil boiler today customer left me to it whilst I serviced it so had a bit of a play with it. You can defanitly notice the difference.

 

[DirksPlumbing]

..., Next boiler you go to, if you have the time, set her at 12%, then after a few starts back her off to 11.5%, listen to how much smoother she starts, and then compare your CO/CO2 ratios.

Hmmm, we are talking about a Green Star boiler here. You should do yourself a favour and stick to the MIs on them. There is a reason why they have different setups for different nozzles and different baffle combinations.
See it like that: There have been thousands and thousands invested to find the optimum setup for each configuration on the WBs. Pretty much a waste then trying to proof them wrong.

And with the low CO2 you are likely to have to change the photocell every now and again as the good old MZ770 is a bit sensitive to that. (I know its not anymore in the GS) Apart from that I just commissioned a GS Camray these days. Sitting on 11.3 CO2 but MI stated 12.0 for this setup. The combustion efficiency went up another 0.3% by setting it correctly. And I sleep better too.

Keeps me on the job having guys going round servicing oil boilers by ear and fitting nozzles as they come to hand. I hope there will always be plenty of them around.
Edit: I am not meaning you Croppie. I am talking about the guys without smoke pump, FGA, gauge etc.

 

[SimonG]

Unfortunately the thousands and thousands spent on finding the optimum settings are with the boiler sat on a workbench and not out on a bleak windswept hill.

We have one bloke around our way who's only piece of equipment for oil servicing is a henry hoover.

 

[Best]

Unfortunately the thousands and thousands spent on finding the optimum settings are with the boiler sat on a workbench and not out on a bleak windswept hill.

We have one bloke around our way who's only piece of equipment for oil servicing is a henry hoover.

Lol! Some don't even use a cleaner either! :smile:
A lot of people tell me their "service engineer" only takes literally 10 minutes for a full service!
As to the boiler location, a boiler on top of a hill, with a conventional flue pipe will be a lot different to set than a boiler that is in the middle of a town with high buildings or trees near, or boilers that have very low flues or low level flues.

 

[Millsy 82]

10 minutes!! it takes me just over an hour for a clean boiler.

I went back today to service it. Got it all ready to fire thought I will give worcester a call an see what the settings for both adjustments was on the burner (Air and Break plate?) I had the manual printed off in front of me but nothing about this other setting and the girl I spoke to at worcester did not know anything about it. So tried to set it up on the air and pump pressure but it wouldnt stay lit and kept sparking every now and then double checked photocell.

Ran ok with photocell pointing at light but smoking like mad didnt need to use my pump adjusted air down to about 12% again tried with photocell in started sparking again so still not right. Took a note of what the break plate setting was and as the customer left me to it had a bit of a play with it and got the boiler running and lighting an absolute dream stayed with it for an extra half hour just in case then re tested smoke and CO2 all spot on set the CO2 at 11.8% and as it was running beutifully left it at that.

So many thanks for all the replies helped alot.

 

[Nostrum]

I always thought the MI's state CO2 for maximum efficiency. In reality you sometime have to sacrifice a few % to get a cleaner burn.

 

[DirksPlumbing]

I always thought the MI's state CO2 for maximum efficiency. In reality you sometime have to sacrifice a few % to get a cleaner burn.

I have not seen WBs R@D equipment but normally it starts with arrays of temperature sensors. Because a to high surface temperature is gonna destroying the steel of the combustion chamber and baffles. I am sure most of us have seen the warped baffles already and the brittle crystalline structure.
Then there should be a fga coupled up with metering equipment.
Typically at some point a camera in the combustion chamber and IR-camera outside to spot potential problems should be in use as well.
But then again those things might be simulated nowadays before even the first welding spot is done.
Indeed the MI refer to safe settings in the first instance but some manufacturers do their homeworks pretty good. And WB is the one where I have literally no call backs except services. If they only would find a seal for the flow sensor in the combis that does not soften.

And then someone comes across and decides instead of a .85 80deg EH he is gonna fit a 45 deg full cone nozzle instead because it has the same throughput.
Next thing is the customer asking "But our boiler is only 5 years old how can it be leaking, must be badly manufactured."

 

[Dotty]

A couple of year ago an old boy popped into the yard to buy a couple of fittings off us. He got chatting to me as I was commissioning the new office boiler at the time.
"You use that equipment on oil too?"
"Yeah course. The analyser anyway."
He tapped his nose. "Can't beat an engineer's eye, boy. That stuff's a waste of money!"
I started with asking how he could spot the smoke in a plume on an HE. Then how many regular customers he had.

I think I was swearing at him for a good 10 minutes up until he closed the car door and drove off.

 

[Best]

The people that boast about "never having their boiler serviced & it being 10 years old!" I find very funny. They think their boiler must be running spot on & have saved a fortune in servicing costs. Usually their boiler will have had way too much air mix & therefore highly inefficient, but less likely to soot. Not forgetting the shell & baffles will be caked with corrosive blocking sulphur & the nozzle likely blocked inside. That said, in fairness, many boilers are not done properly by service engineers & are a waste of money.
I think I read that the optimum CO2 with oil is 15% (meaning the oil is fully used) but this figure is not attainable as boiler will soot etc.

 

[peteheat]

Most plumbers don't realise the manufacturer sets the air high on the boiler so it will start when installed, many just leave it manufacturers settings thinking they are correct when the truth is the opposite.

How many times have you got the smell of fuel in the wind before even ringing the door bell?

 

[DirksPlumbing]

I find NG boiler usually set up pretty good at factory, oil most of the time but on the LPG versions it seems every third boiler that would be At Risk with factory settings.

 

[PhilC]

Our Greenstar Utility 32/50 has just been serviced, and, unlike Millsy, the engineer couldn't get it to the MI figures. Should I be worried? Readings on the invoice are:
CO2 14.2 (MI 12.0)
Flue temp 87 (MI 85)
Smoke 0
Pump 115 (MI 120)
CO 88
He did a thorough job, taking over an hour to clean both heat exchangers, and cleaned the condensate trap. Nozzle used is right, 1.10 45S. I'm just a bit concerned the CO2 is high - what does this mean in terms of efficiency? Not sure if it's relevant, but flue is conventional, approx 10m high from boiler in basement to top of chimney.

One other odd thing - when I rang to confirm the booking, they said they might need to replace the flexi oil lines (£18 each). In our last house they weren't replaced in 15 years and never gave any problem. Is this something new dreamed up by OFTEC?

 

[Roger Welton]

At 14.2% CO2 I'd imagine it wpont be long before he's back to clean it out again!!