Worcester Danesmoor 15/19 air setting won't go high enough!

[Duker996]

Manual States it should approximately be 9 but 7 is the highest the needle will go to? The screw just jumps at around 7. Any ideas?

 

[Best]

It is slipping on the bolt adjuster. This can be checked by looking in at the internal adjustment door
You need to use an analyser and oil pressure gauge to set up the boiler

 

[Duker996]

Thanks for the reply Best.

I've set the oil pressure correct but the CO2 reading cannot be set correctly because I can't adjust the air any further, I am using an analyser too :wink:

 

[Best]

A lot of them Riello RDB air adjusters slip on the thread of the bolt. Or the Allen bolt end can wear. The little sliding internal air door can also jam. You can usually adjust the bolt manually if it is slipping on the door thread by removing the plastic air cover or snorkel spigot (whichever it fitted) and turning thread by hand. Obviously turn the power off first.

 

[Duker996]

Once again thanks for taking the time to reply.

I removed the burner, took the blast tube off, removed the back cover, pulled the door manually open and wound the bolt at the same time. Without the pressure of the door against it I could move the bolt ok. As it happens it needed to be set at about 5 to get the correct 11.5 co2 reading, nowhere near the 9 the MI suggests!

 

[Best]

No problem.
The MIs can be wrong and the air setting would, if anything be recommended on the high side a little to keep on the clean side for to be okay in all situations, but obviously wrong for efficiency.

 

[Geyser]

I've never found recommended air setting in manual relevant for servicing. A rough starting point for commissioning and first fire up.

 

[Duker996]

I was going by the table in the MI, nozzle size, co2 readung, oil pump pressure, approx flue temperature and approx air shutter number.

Nowhere on the table did it say use only on first start up.

 

[Best]

I was going by the table in the MI, nozzle size, co2 readung, oil pump pressure, approx flue temperature and approx air shutter number.

Nowhere on the table did it say use only on first start up.

It is a guide for start up I guess on the air setting number and fgt, - other readings are normally the factory settings - like oil pressure & correct nozzle for output. Obviously other settings are on MIs for lowering & highering output & different size nozzles.
They always state that air setting needs adjusted by analyser for commissioning.
Just be careful trying to obey recommended CO2 as it can vary on what temperature the air is that the boiler draws in. On a cold day the CO2 lowers for example but if you checked the CO2 on a day that is 20degrees you would find it should be tested & set to MIs. On really hot weather it will be higher

 

[Duker996]

I realise it is only a guide, and was always going to set the air damper according to what the analyser co2 readings said. I was using the approx air setting as a starting point then adjusting it down according to the analyser, kind of how you explained in another post!

If thats the case with different temperatures how is it possible to set up a boiler correctly if its border line freezing or a heatwave outside?

Sorry for all the questions, i'm a little green! I've been installing oil boilers for 15 years but have never delved inside them too much, I watched other technicians many many times but it's a bit different doing it yourself when you come up against problems!

Last nights boiler was the father in laws. Its due to be replaced in a couple of months so I said I'd give it a service for him and use it as experience for myself. He said the last engineer only took 15 minutes to service it where as I was over two hours..........clearly wasn't being done correctly!

 

[Best]

The analyser will also take the air temperature at boiler. This will then let you work out if the CO2 needs slightly higher or lower than the MIs. Only problem I see with analyser doing this, is some boilers haven't balanced flues and therefore you need the air temperature to be taken beside boiler, but a balanced flue takes its air from outside, so air temperature needs from there. It's a bit of guesswork also. Do not try to get all boilers to MIs CO2 as this can be wrong. For example some say 12%, but that can be too close to limits and maybe better to lower it to just above 11%. Actual locations of boiler and height of flue with have different considerations.
Also a standard efficient oil boiler can cause the chimney/flue to get wet if set to MIs.

 

[Duker996]

The analyser will also take the air temperature at boiler. This will then let you work out if the CO2 needs slightly higher or lower than the MIs. Only problem I see with analyser doing this, is some boilers haven't balanced flues and therefore you need the air temperature to be taken beside boiler, but a balanced flue takes its air from outside, so air temperature needs from there. It's a bit of guesswork also. Do not try to get all boilers to MIs CO2 as this can be wrong. For example some say 12%, but that can be too close to limits and maybe better to lower it to just above 11%. Actual locations of boiler and height of flue with have different considerations.
Also a standard efficient oil boiler can cause the chimney/flue to get wet if set to MIs.

With that in mind, at what temperatures do you start adjusting the co2 levels and by how much(say 10c lower by 1% and 20c raise by 1%)? I guess you could also use the analyser to read the temperature of where the air source is before inserting into the flue.

How does this stand with the warranty also? I could imagine a manufacturer trying to worm out of a warranty claim because the co2 level was set wrong at the last service?!

 

[Geyser]

I use the riello chart downloadable from there site. Air adjustment to outside air temp. Cant link not sure how!

 

[Duker996]

Top man, I've found it

 

[Best]

With that in mind, at what temperatures do you start adjusting the co2 levels and by how much(say 10c lower by 1% and 20c raise by 1%)? I guess you could also use the analyser to read the temperature of where the air source is before inserting into the flue.

How does this stand with the warranty also? I could imagine a manufacturer trying to worm out of a warranty claim because the co2 level was set wrong at the last service?!

The manufacturer can't argue with a printout from analyser showing the air temperature as well as boiler gases result

 

[Best]

I use the riello chart downloadable from there site. Air adjustment to outside air temp. Cant link not sure how!

Here it is, (just cut & paste it to your post) -
http://www.rielloburners.co.uk/lumo/upload_documents/riello_combustionairadjustmentco2outsideair.pdf