Gas Boiler Fault Finding - Ideal Logic

gas boiler fault finding my name's alan hart and in today's video we've got his friendly ex ideal engineer back and he's going to go through some fault finding on a boiler on an ideal logic so hopefully this will give you a little bit of an insight into fault finding also in future videos hopefully we're going to meet up and a better video um better video together and hopefully get some really good quality videos so if you've got any um any videos that you would like us to do on fault finding then please put some comments below and let us know as always in these videos these videos are just for entertainment purposes only please do not look inside a boiler please do not mess about with multimeters unless you've been on the relevant training courses uh without further ado let's go over to the ideal lx ideal engineer good morning um it's me i'm back again i've been away a while um [Music] done some stuff be in some places but uh um before i'd make another video i've not done one in a long time and um thought this one might be useful for um you know people who are new to the industry a lot of people probably know this but i think it's useful to know for boiler repairs um and i'm going to talk about electrical testing of the boiler i'm gonna um explain a few things try and show you a few things show you what i do um i do it on every job um [Music] and if you are a diagnostic engineer or repair boiler this is really handy to know um because a lot of people when they repair boilers they go for parts um you know let's say you've got a forward a pump and you're not getting power to the pump people immediately assume it's the circuit board without even testing the harness i've seen it so many times before so i just want to show you how to do some electrical checks mainly mainly they're going to they're going to be dead tests we're not going to be doing much live testing today um we're going to be doing like resistance testing and continuity testing so i thought i'd show you um this here this is this is the ohm's law triangle um i'm not an electrician by the way i'm don't claim to be an electrician i've done some electrical courses um i'm qualified as an electrician but i've never really practiced they've never done any proper testing with megas or rewired houses i only did it just because i wanted to understand the principles and apply it in my job so please don't um slate me any electricians i'm not trying to say i'm an electrician but i just wanted it's handy to notice if you're if you're working on boilers on electronics so um this is the ohm's law triangle and basically the principle is with the vol you can work out um you can work out either the voltage which is v i the current which is your amps and our resistance is your resistance so um by multiplying or dividing or subtracting any of these two you can find the other missing um principle if you will so for instance to find the amps pulling on a component whatever what have you if you know the voltage and the resistance you can divide the voltage by the resistance and it'll give you your amps so you divide the voltage by r gives you i to find volts you would times current by resistance so you times these two together and you'd find voltage and to find resistance you would divide voltage by your i which is your amps and for example and i'll show you this in a bit later so we've got an ideal logic 24 volt gas valve so we know it's 24 volts and we know that the amperage pulling through is 0.2 i which is 0.2 amps so if i divide that 24 by 0.2 it gives me 120 ohms so that gas valve in that boiler should be reading 120 ohms and if it isn't it could be a problem with the coil so 120 yes you mean it could be a little bit over like 10 percent over under 125 whatever you know you'd be all right with that so this is just a little bit of an example i'm going to show you how to do some dead testing um not just on the components on the harnesses as well because um you want to be checking like the insulation quality of the harnesses um it's useful for checking them um especially over time when your product's been used and it's had heat from the boiler or possibly water damage um on the harnesses and it can have an effect on the operation of the cables so um like i said people normally go for the parts but it's not always the part in my in my experience i've had a lot of problems with harnesses and um so you know the test that i'm going to show you it they can detect like the impending insulation failure um before it occurs or it can detect faults that could put your your life in danger could be causing a safety issue or it could cause a fault on the appliance so um we're gonna go to the boiler now and i'm gonna show you how i test the boiler um before i touch it and then i'll show you some dead tests on components which is handy to know um before you even put any light power to it obviously dead testing's a lot safer as well so you're not actually working with live and voltage which is you know always you know a better way to work if you can so uh yeah we'll go to the boiler now and we'll show you some tests so here we are at the boiler um we've got our testing equipment set up does she down and before we touch the boiler we're going to make sure it's safe to touch we've got a logic here um there could be a fault on the boiler there could be a wiring issue that's causing the case to become live and we don't want to just be touching it taking the case off so before we um do any tests on the boiler we'll use our non-contact voltage detector these are not 100 effective they are something handy to have but i wouldn't use them for electrical testing and not really that reliable you can get static that can cause it to go off so just be aware of that it's good for a quick quick reference but nothing more than that so what you do you'd test it out another source um i'm going to use the spur you use a socket or something in the kitchen to make sure it's working properly but the test purpose is i'm going to use the spur then you'd wave it over the boiler casing and this is plastic uh i'm gonna use the side of the metallic casing multiple locations are metal so you can just wave it on the front but on this instance i'm just going to use the side seems okay they need extraneous pipe work underneath that seems all right back at the spur knock the power off now the next test we're going to do is um we're going to test the f from the spur to the boiler to make sure we've got a good earth as well it's important to check the earth because obviously not just for safety purposes it's also um you know the boiler needs to go for ignition or what have you so um i'll just set up the test and then we'll we'll do that next one okay so i've taken the cover off the boiler um the power's off and i need to um make sure it's safe to work on and i'm going to do what i call a dead live dead test so i'm going to test the incoming live neutral nerve while the power's off test it while the power's on and then test it while it's off again and to do that i need an approved electrical tester um i've got one here and i'm gonna test to make sure that it works it functions properly before i do any work on the boiler so i've got a proven unit and i'll put these two probes down and then we've got the light indicators to say there we go to see that this proven unit seems to be functioning properly and so does the tester so we're going to expose the live neutral on earth and our first test is going to be between live and earth so we'll get on the live there and then f zero volts we'll go live to neutral zero volts you go to earth zero volts and then any income in uh switch lives room stats um pump lies anything else coming to the boiler we also want to go across those to make sure they're not connected to a different power supply so go across any other incoming cables um this has got a link in but i'm just showing you that that is also zero volts now what we'll do we'll turn the power back on and then we go lighter up again [Music] on some neutral [Music] neutral 240 neutral towards zero volts or less than 15 bucks and again go across any exterior power supply see there we've got a 240 volt room start linked so we've also done polarity there we've not just done um you know correct voltage coming in we've also done polarity because we've got two for between right through 240 between light and neutral and zero volt between neutral that's our polarity testing also we'll knock off the power again i'm gonna do it one more time so we'll go down to zero volts to neutral zero volts neutral to f0 volts and zero volts on my switch life again go back to the proving unit one more time there you go and that's the first part of the test done now we're going to use our multimeter um for the short circuit resistance to earth and earth continuity um so we're going to set our multimeter to arms again touch our probes together so we got one point 0.9 so we'll subtract that from the test that we carry out on this um on this boiler so we'll do um resistance to earth first so we'll go to lightsworth and then neutral to earth so what we're doing now we're just making sure that we're not you know our cables are in good order uh the installation is good order and we're not inadvertently touching enough so what we don't want to see we want to see greater we want to see mega ohms or ol really um that's the desired reason we want so we'll go live to f oh well mega ohms so that means we haven't got a circuit nothing to touch in then we'll go neutral to earth again oh well microns that's good and then we'll go short circuit which is live to neutral we want greater than 15 ohms on this one we've got 292 kilo ohms so that's also fine so we've not got a short circuit anything less than say 15 15 ohms or less 10 ohms or left would be a short circuit so um we want mega ohms ideally oh well but 290 kilo ohms is far enough out there we know we've not got a short surface so that's short circuit um from resistance to earth so now we want to do our continuity so we want to test um one point this is gonna be difficult this because i need to go to i'm not gonna do all five points i'll just show you the one point where i can so we put our probe on the earth and our other probe we want to go five points on the on the boiler um try and jam again so i'll go one point there we'll hold on and i'll touch the gas valve one point five but we we had one home with our lead so we have to subtract the one on from our lead so it's 1.3 which is good i'll carry on while it's working pump again that's a good earth connection we'll go fan good connection and i'll go detection probe [Music] so this is taking probably five to ten minutes for me to show you how to do it but if you're doing it by yourself it takes literally two minutes so we've done a safe to touch incoming after the boiler um deadline dead short circuit polarity resistance to her from earth continuity they're the the main electrical checks and now i'll expose the circuit board and we'll do some dead testing on components and i'll show you the the reading from the gas valve where we measured we worked out how many how many ohms of resistance should be through it i'll set that up now right so we've determined that the incoming power cables are in good order the correct way around with the polarity um you know they're in good order no short circuits there's there's no um you know damage to the cables and um we know that any faults on this boiler would have nothing to do with the incoming supply so we've rolled that out and we've ruled it safe to work on so now we're going to do some dead tests on the boiler so the power's off um we can test for resistance and we can test continuity through different components so components like switches like water pressure switch air pressure switch overheats that power switch is on the boiler they're all just continuity so we just want less than one arm through those anything that has um like moving windings pumps fans gas files thermistors they're gonna have a readable resistance so we're gonna need to know what it is like i said we worked out uh what the resistance on the gas file is um and to test the thermistors you would need them for mr char uh i think i've done [Music] done a video about that in the past i won't go over that again um but i'll just show you how to how you would test the thermistor mister so i've identified the harness the feminist harness which is the black and pink black and red on this harness and as you can see i'm on the black and pink there i think the black and pink is the flow for mr um and we have got we're set at home so all our tests are gonna be on ohms because we're testing resistance or continuity and we've got a measurement of twelve point one kilo ohms so that's the flow from mister we're measuring like i said you need to finish the chart but i haven't got it with me i'm just showing you how to do it but i would say that that's okay um just because the ball is working and um it sounds it seems about right for you know what i should be doing so now i'm going to go on to i'm going to go across these um cables here this is the gas file this is the stepper motor this is um this is the flow turbine and the low water pressure switch so what i'm going to do i'm going to try and get on the low water pressure switch with one hand this is going to be very difficult to do just give me a moment come on come on there you go i'm on it i'm testing the low water pressure switch now on the black orange and getting 1.1 ohms so that tells me that switch is in the closed position which means it's working um so it's letting it's letting an arm through it which is a good circuit if the switch was open and the pressure dropped you're beginning mega ohms on that switch so i know that that switch is okay and working and we should have enough pressure in the boiler so that's the thermistors and the lower water pressure switch done next one um so that's the little pressure switch this is the stepper motor and this is the gas well i'm gonna i'm not gonna do the stepper motor because i've done that on another video and um it's going to be difficult to test in the course individually i really need two hands for that i should be able to show you this gas 12 one so like i said it's 24 volt gas valve we know we've got 0.2 amps running through it so if i go across this one here and this one here 112 ohms i said it was about 120 112 will do me fine so um we've tested we can test you know components dead testing the boiler is obviously safer switches will be less than at home um for misters windings and gas files pumps fans you'll you're gonna need the readable resistance um you're gonna need to know what it is you can work it out by that ohm's law calculator if if you have the other relevant information the voltage to the uh the component and you know the the current that is pulling in amps you can work out roughly what it's what it needs to be uh with thermistors they are a thermostat resistor so you know obviously with the temperature change the resistance changes through um the resistance changes through the component so therefore the the current flowing through it changes and which will change the amount of voltage that can be pulled through it too so the low voltage that's flowing through the thermistor will change up and down depending on the temperature and resistance and therefore the circuit board will see the voltage change and with the algorithm on the board it will know what temperature that thermistor is at by what voltage it's getting back very low voltage is getting back because the resistance through it um it is squeezing down the amp section pass through or increasing the current that can pass through and therefore the voltage will go up or now and the circuit board will calculate by what voltage is passing through it what temperature the boiler is running at so that's just an electrical test that i do all the time um i don't skip this test this tells me a lot and then i can go looking for um you know we can go looking for um faults once depending on what these tests say like i said when you're doing it at the board you're not just testing the gas valve i'm testing the um the state of the harness too so um you know if you're gonna fault with the harness this test here you know we'll show it up so it's good to know it's good to do and if you're serious about repairing boilers i would uh incorporate these tests into your working practices okay that's gonna be me for now i hope this helps um i'm hopefully gonna be doing some more videos with alan hopefully um on different boilers i've not just worked for an idea i've worked for another manufacturer as well so it'd be nice to maybe um show some of the the component faults and what have you on on other borders too so if anybody wants to see it that is yeah well we'll see what happens thank you for watching bye-bye thank you very much for that mr ideal if you want some more if you want to see some more videos then please put comment below let us know what type of videos you would like and as i've said previously at the start of this video these videos they don't take away the need for going on training courses so in my opinion go on as many of the manufacturers training courses as you can a lot of times them training courses are actually free of charge because they use most manufacturers use marketing budgets to obviously they want to sell you their boilers so they'll use their marketing budgets to fund the training um so they're worth going on um go on as many of the different manufacturers as you possibly can and then also go on any local trading centers if they've got any fault finding courses if they've got any um all to do with boilers really and and then the more of that stuff you can do the better you will be and and the more you will learn um different trainers and different people have different opinions and give you different processes if you like so if you go on as many as possible then you'll learn the way that suits you and helps you the best um so yeah thanks very much thanks for watching thank you to mr ideal or mr x ideal and see you on the next video

Channel: Allen Hart

Views: 10,992

Keywords: combi boiler, gas training videos, gas training, gas boiler

Id: CdHJwLFTzPs

Length: 27min 44sec (1664 seconds)

Published: Mon May 23 2022