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View the thread, titled "Very very Hight Co2 ppm old Myson velarie... Help" which is posted in UK Plumbers Forums on UK Plumbers Forums.
The plastic bit, no 17, locating block... No not replaced this. What is it for? I did not access through bank plate.
No 17 part is to hold the nozzle assembly centre at the front of burner (to keep the nozzle at other end straight) and no 17 also adjusts the nozzle distance to front of diffuser. (It has a bolt threaded through it to pull nozzle out and in.
Do not adjust it!
Update on boiler. Got there this am with new capacitor. On arrival noticed lock out on..Odd considering I had switched off at wall and at boiler and told client not to use boiler.. Different story..
Re-cleaned the now oil wet combustion chamber..*?@*%
Removed burner and removed fan and cleaned loosened air band and cleaned. Found small stone jammed in back of band preventing it closing fully. So when I thought I had closed air band there was actually gap at the back. TOO much air... So with that sorted . I replaced nozzle thanks to Kris's Myson performance data sheet, and set pressure. Done smoke test at low air and adjusted down to 2 smoke. Then fine tuned with FGA. Ended with 11.2 co2, 37% excess air, flue temp 277 C, 70 co ppm. any more air to bring co2 down a bit then co ppm rises. Not sure what the recommended co2 is for that boiler.
Anyway happier with that. All that headache from a 2mm stone..
Must say the air band is very fine movements to tune in. I ended up at just under 1 on the settings.
Re-cleaned the now oil wet combustion chamber..*?@*%
Removed burner and removed fan and cleaned loosened air band and cleaned. Found small stone jammed in back of band preventing it closing fully. So when I thought I had closed air band there was actually gap at the back. TOO much air... So with that sorted . I replaced nozzle thanks to Kris's Myson performance data sheet, and set pressure. Done smoke test at low air and adjusted down to 2 smoke. Then fine tuned with FGA. Ended with 11.2 co2, 37% excess air, flue temp 277 C, 70 co ppm. any more air to bring co2 down a bit then co ppm rises. Not sure what the recommended co2 is for that boiler.
Anyway happier with that. All that headache from a 2mm stone..
Must say the air band is very fine movements to tune in. I ended up at just under 1 on the settings.
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What is the advice around switching off unsafe boiler. I was taught that with oil we have no legal right to disconnect boiler. but if pumping out co @ 800ppm... Surely.. I told client on Friday boiler not safe and do not switch on, 3 times I told him. Could not believe when he said he had it on. Luckily it locked out...
Did you document it was unsafe to use?
I'll pull the fuse and turn the oil off. Document unsafe, get them to sign and keep a copy. After that its up to them.
Yes put it on a job sheet that I start before starting job. Would normally get them to initial any changes etc. I get then to sign and authorization to proceed before I start any job. Client had left before I finished and not back before I left, so phoned client and explained all to client before I left and he seemed happy.. Should have waited until they returned to sign, but next job waiting...
I turn switches off and sometimes remove the solenoid to prevent burner firing.
Fuse out and oil off for extra safety.
Can’t trust customers or friends they bring later to interfere. Or children obviously can be at switches.
Ill keep that in mind. Ill take solenoid with me. For better piece of mind.
You don’t want the Co2 much more than 11% for that burner.
There was some of them supplied with a slightly different blast tube and you will find it had to burn slightly higher smoke number to achieve reasonable CO2.
I have the actual paperwork for the Velaires, but can’t be bothered looking for it.
I also remove the solenoid on boilers that haven’t full isolation switches, just to be safe when I go out to van to get tools or parts.
Don’t want to walk back into a fire. 😱
Thats good about the smoke number, I ended up with about a 2 smoke , but any less pushed other figures out..
Sometimes you just have to be unconcerned with the CO2 being a little low and be happy the boiler is running clean. Over 10% is fine on some old burners I find.
That Electro oil burner was a great burner though. Must be over 30 years old if orange colour
At the figures above should I be worried about sooting up then.
Job all done, dont really want to say to client I have to go back and do more.. But if it will be all sooted up in a few weeks then better sort.
The figures seem very good.
Much the same as a new type burner would be set at.
Co is a bit high, but not bad
Smaller ?.. MI set at mid range of burner 60000btu
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