multimeter boiler breakdown/service

[richardb1231]

Hi everyone,

Im an apprentice working on alot of boiler breakdowns. The guy I work with never really uses a multimeter for fault finding (unless its on a glowworm and the manual says he has to). I went on my gas course recently and realised there are guys using their multimeters to diagnose a problem -probably with a great deal more accuracy, and less phone bills to manufacturers!

Does anyone know anywhere i can read up on the best way to use my multi meter for this reason? Or can anyone give me a few pointers on the best ways to use it? Looked at that Mr. Combi course but im a bit broke really.

Cheers

 

[Rob]

Does he just stick his neon on everything. Thats what most installers do.

DMM is an essential when working on boilers. Get a cheapo one to start with.

Baxis boiler courses were pretty good for the basics and very generic. They try and teach you how to fix boilers rather than just sell their products so give them a look.

There's also loadsa books on amazon etc aswell.

 

[landyandy]

Baxis boiler courses were pretty good for the basics and very generic. They try and teach you how to fix boilers rather than just sell their products so give them a look.

I have been on quite a few manufacturers courses. The prices range from foc to £50. They have all been very informative and all use multimeters to fault find. The Baxi course was by far the best, especially for engineers who need to get to grips with multimeters.

Andy.

 

[richardb1231]

yeah that baxi course looks perfect.

been trying out the multimeter with batteries, in the meantime, think ill stay away from the mains...

thanks!

 

[gavinda]

maybe look elsewhere for your apprenticeship. you're gonna struggle witht the assesments without a meter. shocking really how many guys dont use em.

got called to help an eng last week. customer had hot water, hot wahter and heating, but no heating on its own. the eng spent an hour and a half plus a room stt and a mid pos valve.



the was no hot water off wire on the prog. .

 

[bengasman]

TLC do a very good value for money multimeter, they are only a tenner and mine has been living on the floor behind the driversseat for over a year.
Flukes are the dogs, but you pay for them. They have one or two models that measure micro-amps, handy if you want to test rectification.

 

[OilLecky]

Richard,

You need to be able to use a multi-meter as though it was your best friend. You and the other posters are right. Get a cheap one at first and practice on batteries etc. Either go to Maplins or send off for a pack of mixed components and practice with them. Learn to read the resistance of various things. See what happens to the current when you connect a capacitor to a battery with your multi-meter in series.
Remember! Only read resistance with power off. You can read voltage anywhere because the instrument is then "high resistance" BUT on current , i.e. amps / milli-amps etc the meter is very low resistance and if you connect it across (in parallel with) a supply it will either blow the meter internal fuse or blow the meter up!
When you are happy with all these things and not likely to make a mistake, a Fluke 116 is a nice piece of kit for heating etc. It measures temperature and capacitance as well as ohms volts amps etc.
To sum up. Practice with your meter, learn to interpret what it is telling you and trust it! Anyone can use guesswork.

 

[Paul Barker]

You can often get one at Maplins which is adequate which also does temperature for about a tenner.

I find the temp sensor very fast to respond and invaluable when checking whether circulation inside and outside the boiler is all well, where it is going wrong. Check temp sensors in the boiler wether they me old fashioned bellows stats or modern negative temperature coefficient thermisters (resistors which change with temperature) overheat stats. Or even just for installing to identify flow and return temps and hot water performance for the Benchmark Log which is something else you will find out about from your next employer, along with how to do a flue flow and spillage test.