Gas analyser readings.

[trolley2182]

Hello there,
I have just had my first gas inspection. I passed!... which is nice... but i have a couple of questions of the more indepth nature about CPA1 etc
Firstly im new to the forum so hello everyone!

Secondly im not sure on the rules on were to post what questions (obviously not for the eyes of the general public)
So if someone can tell me if i can post here first... i will post my question?

 

[Simon F]

Hello trolley, welcome to the forum.
with only one post the only forum areas you will get access to are for general public, that can change with more posts and relevant qualifications.
you could always ask anyway, if its to risky then no one will answer it.

 

[diamondgas]

:welcome: to this place trolley2182

 

[dancinplumba]

welcome trolley

 

[trolley2182]

Hi everyone!

I am fully gas safe registered anyway so that can be checked out if admin want to.

The question i have is about fga. When i did my gas training they brushed over the readings... but told us the important number is the ratio. Obviously your CO O2 PPM are all important figures but it was kinda drilled into me that if any of those numbers were out it would throw the ratio out.

So while having my inspection... he asks me if the ratio of the boiler we were looking at was good. It was a High efficiency boiler and the reading was 0.0003 my reply was yes its burning right.

This is were i got shot down in flames... he told me that i shouldnt presume its right, and that everything had to be checked with the manufactures instructions.

Ok i agreed, but asked... why do they have action levels in the corgi book? For example action level on boilers 0.008?

He told me that thats not the case and that certain boilers action levels are way under that.

Hmmm now im starting to feel a little bit uncomfortable. Anyway once we checked with the manufactures instructions of course it was showed it was burning correctly and all is good. At this point i go to take the probe out, again he asks me what im doing?

Now he tells me that i need to test it again on low flame... reason for this been... is that some boilers have a modulating gas valve but dont have a modulating fan... or because the CO level is not set correctly... so when the appliance is on low flame.. it might not have the correct air to gas ratio even tho it does on high flame.

Im not doubting what he said in anyway. I just wondered if everyone analysers at high and low flame? and if the the corgi figures infact are not relevant, and that you should always check with the manufactures instructions?

 

[dancinplumba]

MI's are the bible, look there first then your corgi book

 

[trolley2182]

Yea... we had it drilled into us that manufactures instructions always overruled the corgi ones... but i thought the corgi ones would always give it you on the safe side if you get me...

like for example it states minimum distance a flue can be from a gutter is 300mm... yet a lot of boilers instructions ive seen state 25mm... so i always thought the corgi ones were over the top "to be on the safe side" instructions, but surely if the action level on a boiler can be alot less than what corgi states... why does corgi state them? What good are they if you have the check with the manufacturer everytime, it kinda makes the figures pointless?

Maybe its just me been a bit pedantic, but im new to the industry and want to make sure everything i touch is 110% right

 

[Simon F]

you should always check with the manufactures instructions?

Yes.
most are more interested in the co2

 

[AWheating]

Yea... we had it drilled into us that manufactures instructions always overruled the corgi ones... but i thought the corgi ones would always give it you on the safe side if you get me...

like for example it states minimum distance a flue can be from a gutter is 300mm... yet a lot of boilers instructions ive seen state 25mm... so i always thought the corgi ones were over the top "to be on the safe side" instructions, but surely if the action level on a boiler can be alot less than what corgi states... why does corgi state them? What good are they if you have the check with the manufacturer everytime, it kinda makes the figures pointless?

Maybe its just me been a bit pedantic, but im new to the industry and want to make sure everything i touch is 110% right

as with most regulations and british/EN standards etc.... they set out the min requirements. If a manufacturer has tested and passed there equipment to be suitable to clearances and measurements different to that of the british standards then they put this into the installation instructions and this can be followed instead of the relevant british standard. The manufacture instructions only apply to the appliance itself and not the complete installation as a whole and as such other building regulations must be adhered to alongside these.

As regards the FGA use, if the MI state a reading at max and min is needed then it must be carried out. This is why its very important that before carrying out any work on a appliance the MI are available and should be followed. The action levels of 0.004 and 0.008 etc..... are a general readings designed by british gas and used in the relevant BS as guidlines but as you have found out each manufacturer and appliance model may have specific measurements.

This said many service engineers will do a "BG service" ignoring the guidelines set out in the MI.

 

[Reg Man]

Its a shame you came away worried about this inspection. The result opens up a few problems with CPA1 training a assessment. In my view for such an important subject this is not good enough. Manufacturer instructions is the bible, but you should be able to make a reasonable assessment on whats right and wrong with an understanding of combustion readings. Thats what the maunfacturers base their instructions on.

The inspector asked you to do high and low range readings, which is sound engineering. Most high efficiency boiler are looking for somthing better than a ratio of 0.0002 at both high and low range. = 10%co2 to 200ppm co

 

[markadams]

If you are told you need to follow the MI every time then I question how you can be expected to have a copy of EVERY boiler MI with you for every job. Often you will not know what the boiler make/model is before arriving at the job.

Mark.

 

[hammers4spanner]

9 times out of ten when you goto a service the heating has been on full whack and you struggle to get the appropriate reading , i have thrown the stat in the fridge before absolute nuisance trying to fga some of the boilers at times

 

[trolley2182]

This is were i felt a little deflated.... I passed my acs by knowing what they taught me but on the inspection i was made to question my work by been told i should know things i wasn't told to pass the exam. On one hand i was been told don't go on corgi figures, always find the manual and go offwtthe mi instructions.... When i asked what the point in the corgi figures i got told to use then if you can find the mi instructions.. then the whole thing about doing it on high flame and low flame... Image sure we were never told this. Corgi book states run appliance for 10 mins and stick your probe in for a min. I learnt a lot to be honest which image glad but id rather have been told this first on my course.

 

[trolley2182]

Sorry "can't" find the mi manual.. Im on my phone with big clumsy fingers

 

[dancinplumba]

If you are told you need to follow the MI every time then I question how you can be expected to have a copy of EVERY boiler MI with you for every job. Often you will not know what the boiler make/model is before arriving at the job.

Mark.

the mi's should be with boiler, if not there is always the interweb

 

[rob2048]

Hi trolley I had the same problem when I had my inspection they don't teach you enough on the CPA 1 course my gas inspector was very helpfull and showed me how it works I still don't totally get it but I know a lot more than I did they should teach you right on the courses you pay a lot for a fga you want to know how it works

 

[stevetheplumber]

Its a shame you came away worried about this inspection. The result opens up a few problems with CPA1 training a assessment. In my view for such an important subject this is not good enough. Manufacturer instructions is the bible, but you should be able to make a reasonable assessment on whats right and wrong with an understanding of combustion readings. Thats what the maunfacturers base their instructions on.

The inspector asked you to do high and low range readings, which is sound engineering. Most high efficiency boiler are looking for somthing better than a ratio of 0.0002 at both high and low range. = 10%co2 to 200ppm co

i agree ive done my cpa and to be honest the only diffence when i came out to when i went in was i was £150 poorer i was expecting to be taught something in some depth about the combustion process and how the readings relate to each other a complete waste of a day

 

[Whn1]

i agree ive done my cpa and to be honest the only diffence when i came out to when i went in was i was £150 poorer i was expecting to be taught something in some depth about the combustion process and how the readings relate to each other a complete waste of a day

I found this with my cpa1, my g3 and to be completely honest even my gas safe to some extent. 90% of what I know is through experience and reading (mainly this forum)

 

[trolley2182]

Thanks for your replys its made me feel alot better that its not just me been stupid. One thing i have taken from the inspection, i have read and read and read up.. talked to a few of the older engineers and i now feel i have a much better understanding of the indepth gas side of thing. There are things ive picked up on gas analysis, gas rating and pressures from looking into things.

I did a landlord cert yesterday and i felt i walked away from it doing a much better job, what alot of it comes down to is the caliber of engineer you learnt off.

The guys i worked with were top notch installers but i never saw them use a manometer for more than a tightness test and i rarely saw them use an analyser. Maybe thats just because they also picked up bad habbits from who they learnt off.

I guess no one knows everything but as long as your willing to keep reading and improve your gas knowledge your moving forward.

I definitely agree that the CPA1 training is not up to much. I felt like my training enabled me to pass the questions, but didnt actually give me any insight in what the readings mean and how to use it.

 

[tom609]

contact the manufacturer if in doubt you shouldnt service an appliance without m,i but we do if there are no m,i instr i always contact manufacturers

 

[Reg Man]

I found this with my cpa1, my g3 and to be completely honest even my gas safe to some extent. 90% of what I know is through experience and reading (mainly this forum)

You don't believe everything posted in this forum? The internet can be a dangerous thing.

 

[george897]

If I don't have the manufacturers instructions I call the manufacturer, I can normally find the MIs online now though with a smartphone.

 

[kirkgas]

Trolley if you want to be pedantic you should strive to get it 100% right as its not possible to get something 110% or like footballers to give 110%, it's only possible to get 110% in something like sales increase etc
Re ratio readings in the CORGI book , these are generally to be used for open flued and flueless appliances as these are older and the MI won't state any figure do a BS Doc was produced containing these action level figures , of course they give figures for Combi boilers etc but they are generic and I always advise students to use specific MI
Action level for some room sealed boiler s is 0,008, and dome are 0.004 and it can depend on the type of components in the boiler
As the GSR guy suggested some boilers must be done on high and low, so again MI is req'd

 

[kirkgas]

Markadams, good luck in court if your defence is based on " but Your Honour, do you know how many different boilers there are out there? I would need a low loader to carry them all" he will say "I'm not interested in how many there are, I want up know why you worked on this one without having all safety info which has us all on court today questioning your competence"

 

[snoopy8888]

When I did my gas training, the tutor always told us to spend more time reading through the MI. Get into a habit of reading it, its your bible.

 

[Deleted member 32524]

Try not to feel too down. I remember feeling like that. You will get more experience and feel you are making progress then something will make you question yourself again. I think that keeping yourself on your toes and questioning yourself is a good thing. You will be all right if you keep looking at the MI'S and keep asking questions. I still sometimes feel like a newbie after a rubbish day of setbacks and problems. Keep your chin up.