book

[bennygas]

evening chaps,

just an idea, and this is only an initial thought - so don't take the proverbial, but "I'm just throwing it out there" (makes me sound like one of them "blue sky thinking" munters - sorry).

I've only been on here a short while, so i don't mean to step on anyones toes or speak out of turn, but I noticed on another thread how people were talking about plumbing/gas textbooks etc, and how there was pretty much an abscence of decent fault finding textbooks/guides on the market. this is something I've found myself, and I know is quite prevalent in the trade (the number of blokes who used to ask me whether I could recommend a decent fault finding book was mental), so there's evidently demand there.

John reginald's book, and the tolley's series are about the best I've come across on the matter. I know vipergas did a book going back a few years ago but that was more on fan flued negative pressure combis, and I don't think any of these books go far enough in terms of their treatment of assessing and diagnosing faults, especially on more modern appliances.

I guess you could argue that more treatment of diagnosing system faults would also be of benefit in terms of coverage of any decent guide (i know reginald did a book on this too, but again, technology's moved on since then).

that then brings me to the main question in my post here - you lot seem bright, well for this time of day at least :shocked3: so have you (or the powers that be) ever considered compiling some of the info and experience in your heads and on this forum into a decent coherent document? Certainly, it could be a minefield in terms of people claiming to have contributed this bit or that bit, or disagreeing as to what causes what fault or whatever, and it would be one heck of an endeavour, but I can't help but think that if someone here doesn't do it, then someone else will, and I think that could be a bit of a sickener.

with the community on here, with the forum's ethos, and a group of engineers who on the whole seem quite switched on (the ones who aren't switched on don't spend there time talking gas out of work hours),it could even be another income stream for the forum. I reckon you could make a go of it.

so has this come up before?

 

[bennygas]

I'm out there on me own with yet another dumbass question aint i...

 

[tamz]

No you're not on your own. Many engineers face the same dilemma's and other than trial and error experience , it is hard learnt.
The answer get hold of a mate who works with Big Gas and get the info from him :wink:
They get a plethora of stuff given to them.

 

[Barry98]

get as many MI`s as you can and go on as many FREE manufactorers courses you can asap , that will help

 

[diamondgas]

bennygas 🙂

Interestingly enough the same thought of a combined knowledge, hints & tips idea for folk came to my mind last week. The "trusted Advisor's" discussed how best to explore this and came up with the sticky "hints and tips" thread. It's in its early days but my hopes was that it'll give GSR engineers a source of accumulated knowledge to tap into 🙂

We need to maybe look at how to expand the wealth of knowledge frequenting these parts IMHO What's your thought?

 

[bennygas]

bod, tamz, thanks for the quick and helpful response, but i think it's diamondgas that sees where I' m coming from. You see, I've been around/in the trade since I was a kid (my dad was on the gas too), and so I already have quite a stash of manuals etc (although I'd love to have a gander at some of the modern BG stuff - especially whatever's going on at watson house!), and tonnes of books, it's just I don't see any decent books on the market that cover fault finding on modern appliances in a decent fashion. It's probably a bit of an old habit of mine (I used to be a technical editor for a publisher years ago, and used to have to spot places in the market for book ideas), but I can see a big gap for a book/guide or something similar in this case.

I think if there was a good book/download/forum out there that covered proven techniques, it could do well. for example, the gAspect little book of boilers was fine, but it imho it was overpriced for what it was, and it covered how boilers worked (and only a few boilers at that) - not how they don't work and if so, how to go about repairing them. I know knowledge of how something works implies knowledge of how to diagnose and repair, but I think a more direct approach to diagnosis, testing and rectification of faults is more suitable to most engineers.

The question is, how to approach it. if the issue of fault finding is discussed on a case by case basis, appliance by appliance, you quickly end up with a catologue of faults and solutions which is quite unwieldly, difficult to exercise any kind of quality control over etc. however, if the information and experience could be condensed into a knowledge based method of fault finding (illustrated by real world examples), the guide could be kept much shorter with appendices to accommodate special/unusual cases and updates (indeed, appendices could be written to cover techniques and procedures that are common to multiple situations - thus enabling them to be refered to separately. for example, you could have a section on say, erm, testing an a.p.s. which if you were dealing with a case whereby an ignition fault was suspected, you could say, right, check this, see if you've got that, and if you're not sure how to do this bit, have a look in section x for guidance on how to do y. does that make sense?

if it was to be that a guide was being developed, maybe an outline could be something like this:

1. General operation of different types of appliances - you'd almost need to have a section like this is any guide as underpinning knowledge, it would also enable terminology to be discussed and set, and general operation and then fault logic and a process of elimination to be discussed. this section would probably also be a good place for a disclaimer to cover safe working practices and testing, and also for discussion of testing for safe isolation, polarity testing, short circuit test etc (possibly even discussion of how faults could be picked up at this stage).

I think it's important to focus on appliance operation and fault diagnosis/rectification alone - if you try to cover safety/requirements to any great extent, you're increasing liability should anyone make a mistake on the back of guidance, but also industry code of practice is subject to change and could therefore render some guidance obsolete, which would then require re-working/re-appraisal not to mention keeping track of all the sections of text/guidance affected by change/s. it's not just that, why spend time re-inventing the wheel? there's some really good guidance on safety testing etc out there already.

Suggested types of appliance to base discussion around -
standard efficiency natural draught heat only (e.g. baxi wm/ideal wlx or similar), standard efficiency f/draught heat only (e.g. baxi solo pf);

standard efficiency combi (e.g. could contrast the operation of the 24i with 24cdi or possibly old o/f vaillant - use one with water section operated flow switch arrangement, although old 242 could be a bit too complex); turbomax plus would be a nice variant.

condensing appliances - forced draught burner, condense trap etc. heat only e.g. ecotec 415/418, then on to combis -e.g hall effect water flow sensor, could be based on something like ecomax/ecotec or even the baxi 100 he as it has that arrangement with the fsd interruptor going through the condense trap.

2. Types of components - general positioning, the implications of what they do, and how problems/faults are manifested when they don't work and why. this could then cover the testing of these components. For example:

Overheat stats (those linked directly to electronics, t/couple interruptor types), symptoms of overheat faults and possible underlying causes. Ruling out a faulty stat (e.g. voltage testing at pcb or other components in series, testing the component - resistance/continuity testing, bridging out to test etc). Resetting different types, and the implications of resetting - e.g. overheat fault may persist, having origin elsewhere within appliance/system (e.g. poor ciculation).

System water pressure switches/sensors - similar treatment to overheat stat I guess, but with discussion about modes of failure, variants and their behaviour etc.

Air pressure switches - testing the component electrically - what you're looking for and when, things that affect the a.p.s. - venturi and connecting hoses - common problem with these (e.g splits, debris, condensation). Hints to aid diagnosis - e.g. case on case off effect, poor combustion circuit seals etc).

Fans (negative pressure appliances and first generation positive pressure (e.g. netaheat)) - signs of wear/labouring (e.g. bearing debris/deposits, noise, off-axis gyration, heat damage), general discussion of expected resistance range, possible problems with motor cooling impeller/s.

Fans - forced draught/positive pressure appliances. broad discussion of zero governors (not being shy to point reader to TBs on subject), why they're used e.g. reduced excess air. Emphasis on use of FGA and MIs for any work/adjustment. The need to check combustion at high and low gas rate (re: offset adjustment). Discussion of how voltages to and from fan are monitored and used to infer correct gas rate and hence modulation (and how measuring voltages to/from this component could help isolate the origin of faults). Other possible/known or common faults on this kind of set up.

Thermistors: (e.g. 2 wire, 1 wire (e.g. vaillant), expected bahaviour w.r.t. temp (ntc vs ptc), testing resistance, bridging out (e.g. ptc) or disconnecting leads (ntc).

Flow switch arrangements - diaphragm based water section types, hall effect devices, possibly some variants - e.g. brittony combi float thing-amy-jig.

Gas valves - generic h/well v4600 testing and operation (testing solenoid, two stage ignition, possible faults resulting from slow opening/closing, generic discussion on moduregs built on back of solenoid discussion in v4600 section, could show example of old vaillant 242 gas valve and diaphragm pump as being another way of doing things, but I think this could get a bit messy if not careful.

fsd arrangements - t/couple, interrupted t/couple, flame conductance, flame rectification (including interrupted types). possible issues - e.g. dirty probes, poor earthing, interruptions, poor flame picture/incorrect gas rate/bp, could link section in with discussion of oxypilot/asd.

domestic calorifier/domestic heat exchanger - problems re scale and magnetite, diagnosing faults - e.g. perforated and blocked cases. diagnosing blockage, cycling, fluctuating dhw temperatures. primary side - elevated flow temp, change in temperature differential across phex as compared to expected drop, on domestic side - scaling, affect upon flow rate etc etc. guess you could also have a bit on main heat exchangers and some of the faults found with these - e.g. some of the implications of perforated h/exchangers, the affects of condense upon some alloys used etc...

diverter valve types and fault symptoms and diagnosis with regards to them.
pcb and wiring harness faults and testing/hints/tips.

it'd be good to have a bit in there on the importance of seals on positive pressure appliances - and methods of testing, things to be mindful of etc, just general guidance i guess, but should include inspection/replacement of seals where appropriate together with discussion of implications of poor sealing and perforations in combustion circuit.

there are probably loads of other bits that could be added to here, this is just a list to get things going.

3. Case studies - within some constraints, most boilers do the same thing, they just do it in slightly different ways. Examples could be given of faults which occur on each appliance/appliance type and how they can be diagnosed and rectified. the more of these the better, but they must convey best practice in a logical, thorough and safe manner.

I know this is a pretty massive list at an early stagewhat would be a massive amount of work, but I'm hoping that maybe the ball could be set rolling in....

 

[diamondgas]

A lot of thought and nearly a book in its self bennygas 🙂.... Get some of your experience down on paper and pm puddle. the material can then be discussed and placed in the sticky thread if appropriate .. A lot of thought from yourself ... 🙂

 

[bennygas]

i may well do yet diamondgas, where to start though eh? we'll see.:smiley2:

 

[anth001]

....no gas engineer knows everything.....i don't care how long you have been in the trade.

MI, as always....and just to prove that....they even have a technical line. but to be honest and fair, fault finding etc is not for all.....some are installers and some are rectifiers......there are courses out there....but as a newbie, the simple answer is....on the job experience......and if you do not have the answer....your mate might.....

 

[anth001]

........read....and re-read and experience the power of the faulty boiler....Main 30he usually!!!lol

 

[bennygas]

quite agree with you anth, every day you learn something new in this job. it's the best part of it. work for me has always covered both installing and fault finding (needs must when you're self-employed - if you can't install or fix something, you lose the work, and possibly the client). i would say though that if i blindly followed mi's i would've changed a lot more pcbs, thermistors etc than necessary - and like you say, that's where the experience comes in. i don't know whether i was clear enough in my op, but the question i was asking was more pointed towards whether or not a concerted effort was being made to compile a decent guide to fault finding (cos i think there's a lot of people out there who'd benefit from it), not where can i find one. does that make sense?