Flue analyser on back boiler

[amy]

Hi, I am aware of how we test for spillage first on back boiler then with back boiler and fire working.
I was wondering if this is the way we would test with the flue analyser, I havn't seen a back boiler tested with the analyser yet. Where would we position the analyser when testing and with which probe attachment.
Thx again,
Amy.

 

[Billy Bob Bob]

cast iron heat exchangers fitted to the majority of back boilers should not be tested with a fga due to shale in the rough cast heat exchanger always best to do a full service

 

[amy]

I would have completed a full service of course, just thought it good practice to finish with the FGA test, college don't have back boilers set up for some reason.

 

[kirkgas]

cast iron heat exchangers fitted to the majority of back boilers should not be tested with a fga due to shale in the rough cast heat exchanger always best to do a full service

i am not disagreeing with a full service on a BBU but to answer the question, i use the straight probe, and insert it in beside the fire spigot where it joins the BBU spigot making sure it is in far enough to take a reading from both, the target figure tables in the CPA1 training has figures for BBU's so the OP is right to ask where to check the reading

 

[Billy Bob Bob]

not on a bbu,think about it,you have checked ventilation, you have done your cleaning,done all the tests,checked the pressures whats a fga going to tell you? nothing you have not tested already and due to the type of heat exchanger it may give the wrong readings anyway

 

[amy]

Thx, Which is the correct answer,.
I always find things like this very hard to remember when there are different answers given, I asked similar question to college tutors and they too contrdicted each other.

 

[jammydodger]

a fga is used for determining the level of service. i have never used a fga on a bbu. it takes at least an hour n and a half for a full service already.

 

[Billy Bob Bob]

Thx, Which is the correct answer,.
I always find things like this very hard to remember when there are different answers given, I asked similar question to college tutors and they too contrdicted each other.

well think about it after a full service what is a fga going to tell you? nothing because you have done a service so not really required and you need to ask your tutors about shale on cast iron heat exchangers which will affect your reading so a fga on this appliance is a bit pointless

 

[aggis]

I was to understand you didn't use a FGA on a bbu.
Regarding using a FGA after a full service on an appliance it's going to confirm that it is set up & burning correctly.
Peace of mind

 

[kirkgas]

using a FGA after a service on an open flue appliance is only going to confirm what you should already know, that as per your work and checks and knowledge and skill it is either safe or unsafe, flue fow, spillage, BP, gas rate, flame picture (prob missed something) etc etc, i know some people use them to confirm what they think, but to me it shows a lack of confidence in their ability, same as leaving a TT for 3-4 mins instead of 2, "just to be sure". however amy asked a question and as i said action figures are given in the BS so i answered

 

[plumbster3456]

how is it even possible to get the anilyser in there after the bbu and fire are in place? it is too difficult as you have to get right in the flue full service is more than enough and reg 29 checks.
Done my fga1 recently and had this discussion with gas tutors and they said same thing.

 

[plumbster3456]

mistake reg 26 (9)

 

[kyle]

I asked this question today from non other than gas safe man, he simply said if the manufacturers don't ask for a flue gas analysis to be completed then there is no requirement to do so, end of story. so all the old back boilers as far as i know dont ask for a test.

 

[leakylea]

no need to fga a back boiler, also its al egal requirement to clean any cast iron heat exchanger during a service

 

[bossman]

I'm doing my training and trying to remember everything. electrical checks/visuals 1st always, isolating the fire and removing it, isolating burner assy and gas valve, checking the flue and annular space for a seal, after cleaning nearly everything. the smoke test (flue flow test) with everything out, then reconnect the burner assy and gas valve, without the fire on i take the BP then with the manometer attached tested the FSD, and at that point before replacing the fire get the FGA out and with boiler on obviously, put the analyser straight rod into the spigot duct and take a reading. reconnect the fire took the BP of the fire and done a spillage test.

this is my version of back boiler service if I've missed anything could you please correct me as i have my ACS assessments in a month, and any help would be much appreciated. as books and standards are very helpful but its always good to get knowledge from experienced engineers.

 

[AWheating]

why not ask your tutor?

we dont give out advise to non gas safe registerd people on the forum now. Your tutor should be the person you ask this question to as they know what they are looking for on your practical exam.


welcome to the forum.

 

[bewsh]

I never do unless I'm being audited - Company procedure apparently. We have to increase the burner pressure to maximum setting and analyse it to make sure it can handle maximum output.

But as someone else mentioned, it takes an hour and a half to do a full service on a BBU/Fire anyway - Which is annoying when the company only schedules 38 mins for us to complete an annual!

 

[kirkgas]

I never do unless I'm being audited - Company procedure apparently. We have to increase the burner pressure to maximum setting and analyse it to make sure it can handle maximum output.

But as someone else mentioned, it takes an hour and a half to do a full service on a BBU/Fire anyway - Which is annoying when the company only schedules 38 mins for us to complete an annual!

It amazes me how many people DON'T do a spillage test with the BP at maximum, on a range rated appliance this means turning BP up to max, do spillage then turn BP back to per set pressure