Gas Training - How A Combi Boiler Works With Roy From Viva Training Academy

gas training how a combi boiler works my name is alan hart and today i've got a very special guest today i'm over at viva training academy and i've got an ex boxy trainer roy he's been a trainer for over 20 years i've been on many of his training courses in my opinion he's one of the best trainers in the industry and we've got ryde today and ryan's going to go through a combi boiler he's going to look at all the different components in the company boiler and he's going to go go through explain how they work so far if you're a new recruit into the industry or just somebody who just wants to know more about boilers then this video is definitely for you so without further ado let's go over to roy this video is for gas safe registered and trainee gas engineers under supervision please comply with the current regulations at the time hi guys it's roy fumble here again at the viva train academy over in halifax and today we're going to have a look inside a combi boiler this particular boiler is a potterton assure which is exactly the same internally as a baxi 600 baksi 800 and many eco compact we're going to look at the various components in there and a little bit basic we're going to go through what those components do why they're in there and also we're going to be stripping some of those components out showing you how easy it is to work on them should you need to get them out so without further ado let's start off and we've got an expansion vessel the reason behind an expansion vessel when you heat water up that water expands it expands four percent its volume so we need to take up the expansion of the water as we're heating it up in there we've got a pump the idea behind the pump very much like in your body you've got a pump pushing blood around your body to keep you going the pump in there is pushing water around the radiator circuit in heating mode or around the plate heat exchanger in hot water mode so coming down to the plot heat exchanger plot heat exchange in there to transfer the heat from your primary water the water that's going around the main heat exchanger it goes through the plate and then your cold water comes in and goes through the other side of that plate and transfers the heat so you get nice hot water coming out of your taps obviously we need to get some fuel in there so we've got a gas valve it's what's called a zero governor we'll explain a little bit more about that when we come to it and we start taking it out we've got a fan in there the fan a little bit like our lungs our lungs allow us to bring air in because we need the oxygen for us to breathe and us to live the boiler needs oxygen for combustion so that's what the fan's doing the air's coming down this air intake tube it's actually a silencer tube modern boilers now they're all trying to outdo each other different manufacturers and this is bax's idea about making the boiler a little bit quieter so it's fetching airing down there and it's mixing in with the fan with the gas so the air gas mixture goes into the fan up through a mixing tube onto the burner and that's going to heat the main heat exchange so you've got the main heat exchanger in there that's the main part that in there is what's converting the heat from the gas into the water which is circulating around your system we've got a diverter motor there which is attached onto a diverter valve that diverts a motor when we turn the tap on it'll lift the pin up so the water goes through the plate heat exchanger and then when we've turned the tap off it stays in that position we get a demand for heating we put our radiators on the motor actions down pushes a pin down and allows the water to go around the heating circuit this is a modern condensing boiler so it's got a condensate trap in there the heat exchanger is producing some condensate that goes into that trap and then it goes out through the condensate path we've also got a low pressure cut-off switch in there the idea behind that is if the pressure in the boiler drops too low it won't fire up it what we call dry fire because we don't want it to fight up if there's no water in there we've also got an overheat thermostat the idea behind that if the boiler gets a little bit too hot that kicks in and it's a safety device we've also got two thermistors one on the return and one tucked away on the floor which we'll see a little bit later on we'll zoom in so you can see those those are both temperature sensors so they're measuring the temperature of the water going out to the radiators or into the plate heat exchanger and then back from the radiator back from the plate heat exchanger we've also got another thermistor down there that one sits in a wet pocket the floor returner both in what's called dry pockets so you don't need to drain down to replace them the one on the hot water side is in a wet pocket that's monitoring the hot water temperature going out to taps we don't want the water to be too hot to scold people so that's the idea behind that we've also got what's called a prv pressure reducer pressure relief valve that's in there because if we get too much pressure if the expansion vessel can't take it apart we get a fault that will start to drip and eventually if the pressure builds up and up and gets to about three bar that will fully discharge and that pipe is normally going outside safe and visible so what we'll do now we'll start taking some of these components out right so now we've looked at the various components we're going to start taking the components out before we take any components out of any boilers make sure you have a set of manufacturers instructions so you fully understand what you're doing obviously ppe the correct tools that you need so the first thing i'm going to remove is the expansion vessel for clarity so you guys can see what i'm doing we've removed the wiring harness out of this boiler we've also took the side panels off on this particular boiler the side panels come off having said that back say do say that all the parts can come out from the front and from experience i know they can i must have stripped one of these boilers down countless times in the past life as a boxy trainer so there's two ways of taking the expansion vessel out if the side panel can come off it's easier to take it off and go out the side if it can it could come out the front and we've got to remove the air guy guide and the bracket so we're going to remove it from the side so the first thing i'm going to do the little tube which feeds it and connects onto the manifold on that there is a little clip so we pull the clip out it's just a little stainless steel clip and then we ease that that tube down and we can leave that out the way on the top of the expansion vessel there is a locking nut so with slapping the locking nut off i tend to use a pair of wide mouth adjustable spanners and all i need to do is just slap that off so that it becomes finger tight i can then get my fingers up there unscrew it remove the locking nut and then easing the expansion vessel down freeze the ball comes out the side and then we've got the expansion vessel now on the expansion vessel there's a label that label explains quite a lot of information on there it says it's seven liters so it's capable of taking seven liters of expansion it's got seven liters of expansion in there there's also a couple of the little diagrams ones explain the type of expansion vessel it is this expansion this has a diaphragm inside it the idea of the diaphragm on one side of it you've got water so the water's coming in there and the other side of it you've got air so there's a schrader valve the other common type of expansion vessel you'll find in our industry is used on unvented cylinders that tends to have a bladder inside it the idea of the bladder is the air is in the bladder sorry the air is outside the bladder the water's in the bladder so the water doesn't touch the metal because of corrosion and contamination in this case we're not too worried about that because in the heating system we put things in like inhibitors and chemicals so on there it's set at a pressure and this one's at point eight of a bar so it comes out the factory at point eight so that's where we should be setting it there's a misconception that if you've got a slight problem with your expansion vessel and it's dripping a little bit through the prv you put more pressure in it takes longer for it to start dripping that's totally wrong you need to set them up as per the manufacturers some are set at one bar some are set at point eight just again refer to the manufacturer's instructions or the little data badge on there it's working pressure is three bar because that ties in with the prv and its maximum test pressure on this particular one is four and a half bar so it's tested up to four and a half bar so in the future we're going to do a video about how to repressurize an expansion vessel and things like that but i'll quickly cover it the main thing when you're re-pressurizing an expansion vessel is you want to get rid of the water pressure before you check the air pressure so you drain the boiler down you don't need to drain the whole of the system you're just taking the pressure out wherever you drain it from and on some boilers there are drain points there are drain cups on the boilers that's the ideal place don't use the prv because if you do i'll guarantee it'll get dirt on it and it'll drip and you'll end up having to replace it so we drain the boiler down we leave the drain point open the reason being is if we need to put air in we want to push that water out we don't want to trap any water pressure which will give us a false reading again we're going to do a video about that later on so that's the expansion vessel so that's come out so i'll just pop that down and the next thing we're going to come to is the pump right so we're going to remove the pump head and common faults that we get with pumps sticking because normally all the systems haven't been flushed you get dirt in the system and on this particular pump there is a hole down the center so you can check the impellers spinning so you can check that it's moving i'll show you now where the screwdriver goes but once we get the head out i'll show you how to do that now this particular boiler is a dry boiler it's not had water in it it's all been drained down one of the features of this particular bowl is there's a little channel so a lot of times when you're draining boilers down you've got all the water out of them but you still have a little bit of residual water in things like your plate exchange in the pump so this one's got a little channel in there there's a little rubber bum that you can slap you can just pull it down and then pop a little container underneath it just so if there's any residual water it'll run down there and trickle into it so what we need is a four mil allen key i tend to use these allen key screwdrivers and then we've got four bolts that we remove so it doesn't really matter which way you take them out and when i pop them back i take the bottom back like i'm tightening up a car tire or a car wheel so opposite so we're into there now this particular pump is a grown fossee rp pump so it's got two connections again once i've got it out i'll explain a little bit more about those so there's two screws there as you can see we can get in it's a little bit tight but there is room to get in there so it's no big shake removing a pump head that's typically most manufacturers now that will sell you the pump heads because it's a cheaper thing than changing a complete pump because a lot of the bodies now are thermal plastic so you don't really need to change the whole body of the pump you just need to replace the heads on there so i've got the last bolt now coming out so there we go there is a little bit of water come out as you can see and it's popping out there draining down so we've got the pump out so that's the impeller that's the bit that's going to spin now this is an erp pump energy related products a few years ago we went on to erp that's you may remember colored labels coming out a b c d it's all about energy efficiency the idea the pump is the biggest energy used inside the boiler so all the manufacturers had to start putting energy related pumps in that's why you've got two connections on there the larger connection is your mains connection your lag neutral earth and the smaller connection is a lower voltage typically it's called a pwm connection power wave modulation in plain english it's con it's talking to the circuit board communicating with the circuit board and depending on how many radiators are open so when the system comes on first thing in the morning and you've got eight to nine radiators all wanting heat the pump will run faster it'll use more energy it'll push the water out as the thermostatic radiator valve starts to close down and you go from maybe eight radiators to seven to six to five the pump doesn't need to use as much energy so it will slow down so that's what erp is you may come across some of the early erp boilers they'll only have the mains connection they won't have that connection in there that connection if it's not in there the pump runs at maximum all the time now one of the features that you can do with an erp pump with it if you suspect you've got poor circulation the pump struggling you could unplug that connection it's low voltage you can unclip it that should get the pump to run on to maximum the other thing you could do as i mentioned you can pop the screwdriver in there so what you're doing you're moving the impeller around so if you went to a pump possibly a house that's been empty somebody's moved out it's not had been occupied for a few months the pump can sometimes seize up so we can pop the little screwdriver in and get that pump running without replacing the pump so that's your erp pump the impel as i mentioned it's a bit small and a standard one because it's all about energy efficiency it's not pushing water it's spinning water the easiest way to explain if you've got a bottle one of these little diet coke bottles or something like that fill it full of water tip it out time it fill it up again spin it around so you've got it circulated then tip it out it empties a lot quicker that's the idea behind these using less energy more efficiency so that's the pump quite simple to remove very very easy to work on it's a sealed unit so we're not going to take anything else from that so i'll just pop that down so the next thing we're going to look at is the air gas unit so we're now talking about the air gas unit so we've got the burner the mixing tube the fan and the air intake so the first thing i'm going to do is just disconnect the spark electrode lead this particular boiler has one electrode that does both spark electrode and rectification some you may find on boilers they've got two one's a spark electrode one's a rectification electrode so the first thing we need to do is remove the air tube so there's a little plastic lug that just pops out and then the air tube comes out the way so let's move that out of the way and then just going to remove a little clip which holds the gas pipe in the gas pipe's flexible so that will just pull out and pop down to one side i'm now going to use a 10 mil nut driver i could use a socket or a spanner and i'm going to remove these bolts so again very similar to removing the pump you've got four and in this case the nuts not bolts that you're removing and again as i said with the pump very similar to when you're removing car wheels i always tend to do opposites it's just a force of habit you may notice um there is a little bit of paint on here when the boiler was put together in the factory the guy or girl who put the burner module in the air gas unit and they'll have marked it to tell the next operative that they'd completely tighten things up so removing all those as you can see just hang in there on the top two so i'm just going to remove it now so this is the air gas unit so first part we've got is the fan so the fan is drawing air drying gassing drying air mixing air and gas in there again very similar to your pump there are two electrical connections a mains connection and again a pwm connection power wave modulation depending on the output that the boiler requires the amount of heat the fan speeds up and slows down that's the idea behind pre-mixed burners it's only using the amount of air and gas that it needs it's not using too much so that's what the idea behind that fan is it's got circuit board built onto the fan which again is communicating with the main circuit board and deciding at what speed it needs to do so they're communicating all the time if you come back up to the burner as we can see we've got the electrode there so it's got a little dog leg on and then we've got the spark gap that's the combustion seal now that seal is made out of flexible elastomeric silicone rubber yes here scott if you're listening i can say elastomeric silicone rubber now i didn't used to be able to what that means is this seal can be reused it doesn't need to be changed every time it's a case of if you d mount the air gas unit check that seal make sure it's still flexible there's a little tip i'm just going to pop it back in it sits into a groove as we move that in an easy way to test to make sure that it's still supple enough is just make sure that you've got it into the groove and then turn it over tap it on the back if it doesn't drop out it's still supple it doesn't need to be replaced some manufacturers they will say you need to replace their seal every time you remove it so again check with the particular boiler manufacturers instructions but back set it's on an as and when basis so the next thing we're going to look at once we've popped this down we're going to go to the gas valve right so here's the gas valve to remove that there are two three millimeter bolts underneath and obviously the gas connection in the real world we'd be isolating the gas making sure that that's that's shut off so i'm just going to remove the two three mil bolts using my uh my allen key so i'm just up underneath and on his short little allen keys allen bolts so i'll pop the first one out into the second one and then we'll pop it out so this particular gas valve is an si t848 gas valve it's being used by lots and lots of manufacturers back to been using sit 858 gas valves for a long long time the subtle difference with this particular one compared to previous models like the eco blue and the duotec or the platinum which you may be familiar with this one is low voltage this one we're talking about around about 12 volts those were 240 volts again it's all about energy efficiency erps using less electricity to power our boilers making them more efficient so because it's what's termed as zero governor what we mean by that is if we tested a pressure on the outlet of the gas valve we may get zero we may get a negative reading it's all down to the way that it's sucking air and gas through the older what we will term normal aspirated boilers like the old baxi 105 the boxy solo things like that you could do a burner pressure we don't do burner pressures on modern condensing boilers because of the zero above we do an inlet working pressure so we have the boiler running and we check the inlet pressure to make sure it's within specification a couple of things on that baxi say that we can adjust the co2s and again later on in the future we're going to do a video of how to set those up and how to how to check them but just quickly under this little screw which is a formula allen key so again i've got my formula allen key i can remove that screw and all i'm doing is unscrewing the little cap take the cap out and under there there's a grub screw and that allows me to adjust my minimum my minimum co2s so i'd have a flue gas analyzer check the specification and i can make sure that that's set up correctly once i've proved that i do need to adjust it after checking things like my air intake and stuff like that the other adjustment i've got is underneath the little blue cover it's a two and a half mil allen screw so again two and a half mil screw and what i've got in there is a little grub screw and i'm closing that down or opening it up and that's affecting my maximum co2s so again in the manufacture instructions it explains the maximum minimum and you force it to max force it to min and that's the adjustments that you can do on that gas valve so again quite a common gas valve out there i know was to use a similar gas valve and but i'd have to double check their instructions to see if it allowed me to adjust it i wouldn't adjust it without checking their instructions so that's the gas valve so following on from that we're going to come to the diverter valve right so we're going to pop the diver to motor off so there's a little clip which comes out then the motor pops off so i'm going to remove the diverter cartridge it's got a replaceable cartridge and again i use my trusted wide mouth adjustable spanner and i put it across the and just ease it to slighten it off once it's slack it can be removed and the idea behind the cartridge is this can be replaced again if the system hasn't been properly flushed out if it's got dirt in the system these things can get dirt on the seats one of the symptoms of that is if i get dirt on this on the bottom seat that's the heating seat so basically that's stopping water going around the heating it only becomes active once the diverter motor actions it and it closes off the hot water part there so one of the symptoms i can get with that is if i get some dirt on the customer's going to be complaining that the radiators are getting warm now we're doing these videos in winter so my customer's not going to complain about the radiators getting warm in winter that's what they want what they will be complaining about is the hot water not being as hot as it could be now again we might think because we're the experts well it's not going to be as warm because the water coming to the house is colder but it's a case of checking things out making sure it's not that in summer dead simple they won't be using the heating they're running a hot tap usually in the fill in a bath or having a shower because the water's on for longer the radiator to start to warm up it's a sure sign that the diverter the washer on there could have failed or it could have got some dirt on this is the latest cartridge it's an old brass cartridge that's all this boiler has ever had the earlier boilers like your eco blues your duotects they used to have a plastic cartridge or plastic and brass they became a little bit brittle after a while and occasionally they'd leak up the spindle so bax has brought out this new cartridge it's got a double o-ring seal on so it's got longer lifespan so that's just a simple diver a cartridge it can move in and out it doesn't share the water it's either all for heating or all for hot water now one of the features on this boiler it has an automatic bypass and the plate heat exchange is used as a bypass the idea of a bypass is the pump when it's running it's creating force now we've already talked about that pump so it modulates down now occasionally it might get to a point where it's modulated on its lowest but the system's become so small it still needs to release some of that energy so we need a bypass we need a wavy short circuiting and what happens is under pressure that seat can be lifted up the hot water seat gets lifted up under pressure and it allows some water to go through the plate heat exchange so that's how this particular boiler has an automatic bypass on it so following on from that we're going to have a look at the hot water and sensor the hall effect sensor so that's the next thing we're going to remove right so we're going to remove the the floor switch it's a hall effect sensor h a double l all that means it works on the principle of the magnet this particular version is a turbine so it spins round on some of the earlier boxy boilers the duotects they use the bobby look very very similar now for ease i'm going to remove the lower pressure cut off switch just to make sure that i can get my box spanner in there without actually causing a problem i could get it on there but there's a chance that i'm going to damage the lower pressure cut off so i'll just remove this i'll just give you a quick word about what this does just before we take the hall effect center so the idea of this little fella is to make sure that the boiler's got pressure in if the pressure drops below half a bar it'll flash up an error code and that means the system needs to be repressurized it won't allow the boiler to operate so that's the idea behind that so we don't fire the boiler without any watering because we don't want to dry fabrics it can damage the main heat exchanger so that's just the low pressure cut off i've just removed that and i put that to one side so now i'm using a box spanner it's an 18 millimeter and it's six sided and i've all well i've had installers turned on so the can't get a spanner that fits it slips it's because the edges are rounded and i'll show you in a bit more detail once we've got it out we'll zoom in so you can see that but a six-sided 18 mil fits perfect and it doesn't slip so i'm just going to pop that on and i'm going to start slapping it off and then i can get in and just start to undo it once it starts freeing off i can then pop it out get it hand tight and then i can remove it so now what i'm going to do is take this in bits it will pull in bits so you can clean them out because again depending on what type of area that you you're working in when i leave yorkshire water is very very soft so we don't tend to get a lot of calcification some areas in the past i've worked up in hartlepool really really hard water up there so the first thing on there's a little filter it's just to stop any large particles actually getting inside there so i'm just going to remove that i just popped it off now inside the end of there there's a floor restrictor now depending on the output of this or the the leakage on the particular boiler that will be set and there's different colors this one's a brown one and then stamped on the top it says 12 liters so this is 12 liters a minute so again this is unscrewed i've slackened this one off i will be honest with you just before we took it out it has been slammed off a little bit but you'd normally pop a spanner on there you don't want to put grips on because the brass is soft fine around where that is you can crush it and damage it so that's popped out underneath there we've now got a fine filter a fine gauze filter saw even smaller particles to stop them getting into the turbine so again i'm just going to tap that and that's popped out so inside there now i've got the little turbine so i'm just going to tap it onto my hand so that's the pivot point that's what the turbine sits onto so it sits on there and if i pop that and that's just a brass housing with an o-ring on it so we'll pop that to one side so that's your turbine that sits onto your pivot point and it allows it to spin so on the top of it there's a magnet now that's not a solid round magnet if you imagine a chocolate cake and there's me and ellen here and we quite like his cake because we're two big lads so we're going to cut it into four pieces because we're a bit greedy we're gonna have two pieces each well my two pieces have got magnet sinks i need a bit of iron allen's haven't got magnets so that bit's mine that bits mine and those two are allens so as it's spinning it picks up magnet no magnet magnet no magnet that's how it knows it's spinning again in future we're going to do a video more in depth so you'll see the little light come on on these they have a little red top because that signifies it's a turbine the one on the duotex which is a bobbin are the platinums or the promaxes all that range they have a clear top so that's your hall effect sensor that's how the circuit board knows the tap's turning on it knows when mrs miggins has turned her tap on that it got it needs a hot water demand so that's the hall effect sensor we can strip them out and clean them if it's a hard water area just to make sure it's going because the complaint is going to be i've got intermittent hot water sometimes the vivo fires up other times it doesn't and then we may see the little light flickering as it's turning the tap on and off so the next thing we're going to have a look at we'll remove the plate heat exchanger so to remove the plate exchange we've got two cross head screws one there and one underneath so we're just going to remove those obviously we've got a lot of parts out of this boiler in in reality to remove a plateau exchanger you wouldn't normally have to remove half these parts that we've done so start slapping that one and then the plate exchanger can come out through there in reality all you'd normally do is just pop the diverter motor and it come out through that gap even with the gas valve in place it would come out so this is the plate heat exchanger you see it's got four holes in the top two holes are for your primary water the water that's going around your main heat exchanger so that's actually coming into this part here and it's going across up and down up and down inside that's like a honeycomb and you've got close proximity of two different plates you've got the plates that are running with your primary water so they're going that way and the plates that are running with your mains water which are running this way so the idea is the two hottest points are together and the two coolest points the primary waters coming in this side and returning back through the pump through the main heat exchanger picking up heat and going there the cold water's coming in going through the plates through there and it's coming out hot through there it's going past this the hot water thermistor the hot water temperature center which we'll come back to shortly so this particular plate exchange it's a 12 plate you will find these in different thicknesses dependent on output of boilers you're not going to get any faster flowrate the bigger the plate you're just going to get hotter transfer so the higher the output boiler probably the thicker the plate the quicker the water gets hotter the output is on the amount of heat that you put in there so typically a 24 kilowatt boiler is going to give you somewhere in the region 9 to 10 liters a minute a 30 litre is going to be 12 13 liters a minute and then you're looking at 36 kilowatts you're talking about 14 15 liters a minute and some of the larger outputs you're 40 kilowatts you're talking 16 maybe 17 liters a minute so that's all based on the that's going into your boiler on this one there's a little diagram that's showing which way the diverter valve goes so that you can't put it in the wrong way around as you can see on this particular one that stood it in between those two connections that one's slightly offset so you can't really put this in the wrong way around so that's your plate heat exchanger so next thing we're going to move on to is the hot water sensor so we're going to remove the uh hot water temperature sensor off the mister as the commonly known and through what's called an ntc sensor what that means is the temperature goes up the resistance goes down and you measure them on resistance quite a common sensor this has been used by quite a lot of other manufacturers baxi's being used in a very similar if not the same sensor for a good number of years on the earlier boilers going back to 105's early duotechs they used to have a fiber washer and that could leak they've now changed over a few years ago to a copper washer so the copper washer is now available as a spare 7201 908 that's your part number if you need one of them it's one of the few partners i can remember so that's the temperature sensor again in future videos we're going to go through testing these sensors but basically that's sending a resistance reading down to the circuit board the circuit board transfers that into a temperature so it knows when the water is getting warm enough it can start to reduce that temperature or reduce the amount of gas to maintain the temperature so the next thing we're going to move on to the floor return thermistors now these two are clip-ons they're both exactly the same they work on the same principle as the hot water thermistor it's just a different style what a lot of manufacturers have realized is if you put a pocket into a pipe so wet pocket sensors you're restricting the flow so the pump's got to work harder we've talked about energy efficient pumps if you put a pocket in your pump's using more energy to overcome the restriction that pocket so a lot of manufacturers have moved over onto clip-on thermistors so this boiler's got two there's one on the floor which i've just removed and the one on the return i've just took off they're exactly the same sensor they work on the same principles the hot water on their nt6 sensors and they work on them around about the same band there are different bands these are 10 000 ohms at 25 degrees so if i measured them with a with a multimeter and the temperature was 25 degrees i'd get a resistance reading of approximately 10 000 ohms again as i said we're going to do a video later on in this series showing how to test these things so those two are your floor return sensors the reason you've got a floor and a return on the boiler is monitoring the floor return temperatures so obviously as the return temperature is creeping up the boiler can modulate down because it's all about energy efficiency so the last thing we're going to look at is the prv your prv is there to relieve pressure it's a pressure relief valve as we've talked about right at the beginning when we talked about the expansion vessel that's taking up the expansion of water if that caused a problem that expansion can't be taken up we don't want the boiler to pop any seals we want it to relieve that pressure this particular one's got a hex head on it so we can actually put a spanner on there and we could if we needed to slacking that off and remove the insides now the actual manufacturers of the valve khalifa his natalia brassware company said they don't want people doing that because it's a safety device well yeah it's a safety device but we're not actually touching the safety device and i've just cleaned it off a little bit there all we're doing is checking this washer it's what's termed a top hat washer because it looks like a little top hat and what can happen is you can get a bit of dirt as you might be able to see on this one there's a little bit of dirt on there now that could be sitting on that seat and it can cause it to drip so can take that out give it a bit of a clean up just make sure it's nice and clean and we've not we've not affected we've not done anything with the cartridge so we can pop that back on and there's a little returning clip or a little returning washer and that can screw back in and then we do it hand tight and then just to make sure it's nipped up we can use the trusty adjustable spanner and just nip it up so that's basically the vast majority of parts on that boiler i haven't covered the condensate trap but that's there to take your condensate and to make sure that any condensate coming from the boiler it forms a water seal it's all because we don't want it anything tracking back up any foul smells and things like that coming from where it's connected into so that's your condensate trap so that covers today's video thanks very much for watching my name's roy fuegler thanks to alan for doing the video catches again at viva training academy in here in halifax look forward to seeing you next time bye thank you very much for that roy and thank you once again to viva training academy for helping and supporting with this channel and helping you guys as well i really appreciate it and if you've got any questions please ask them in the comments below we are going to do some more videos so me and roy are going to spend some time we're going to do some more videos for you so again if you've got any suggestions on what videos would help you if you could put them in comments below that'd be good as well please like share comment subscribe all that good stuff thanks for watching

Channel: Allen Hart

Views: 129,261

Keywords: how a combi boiler works youtube, how a combi boiler system works, how a combi boiler works diagram, how a combi boiler works uk, combi boiler, how a combi boiler works, roy fugler, gas training, gas training videos, gas boiler, viva training academy, gas training course, gas training centre, gas course, gas engineer training, gas training tutorials, gas safe training, gas engineer, gas training uk, allen hart, viva training halifax, baxi, baxi boiler

Id: 9tF1d4TcFhg

Length: 38min 25sec (2305 seconds)

Published: Fri Feb 12 2021