Clearing an #airlock in #heating #systems

hi everyone and welcome along to today's video so it seems a few who are a little bit concerned about draining the old heating system giving it a flush out and renewing the inhibitor after it's been a few years it does need a clean air and some fresh stuff putting in but what's the worry well it seems the main concern is air locks in the system when you fill back up so where are the places to look to find the air that's stopping it from working again once you've filled it up let's have a look with our training of the heating system easy start isn't it just get the water turned off or gather the loft and cut the valve of your fne tank find the drain valve downstairs on the lowest point okay in the house and stick a hose on run it outside and start emptying as it starts to pull it down you'll find you can go up to the upstairs reds and open the air valves and then we'll start to let the air in okay that will completely empty those and as it gets lower you can go downstairs and start letting the air in those open the air valves in every single radar to leave it to run and the system should be empty now there's one exception one other thing you may have this type of system i'll show you in which case you do this and that's to go around each room downstairs and make sure you've not got drop pipes coming down the wall to just one radiator and then another room's got drop pipes coming down to another radar and so forth if they come down and feed two radiators off the same leg that's fine but if that's the case you will find you've probably got a drain valve on each radiator like in this instance on this terrible drawing i've done and you will need to empty each side each leg okay because obviously if you drained it there this leg would still be full up okay so any that are dropped like that put the hose pipe on each drain valve and empty them out as as well as the whole system so make sure you don't leave that one there full up say or leave that one full up because you obviously haven't drained it once it's emptied of course then you start the system flashing you can use flashing agents or whatever you and leave the little tank running in the loft then turn it back on and leave the hose pipe on one of the drain valves and to set it run through the whole system fresh clean water run it through and you can shut the drain valve in there let it fill up a little bit and then let it go again as much as you want until you're fairly happy it's pretty clean and running a bit nicer than it was before and that's when we're ready to put our inhibitor in the top tank before we do that obviously shut the valves off and shut the air and all the radiators off before you start to fill and then add your inhibitor in that little tank normally in the loft and then start to fill the system up and that's where the fun begins when the system looks like it's all full up you've bled everything and you turn it on and you find one or two or maybe all the rads are not going you've got an airlock in a system so where do we start looking and scratching our heads to sort this one out well it's not too bad we can get around this one i'll promise it right let's have a little look here we're going to show you one typical heating system there's lots of different types so don't worry this is not representative of yours it's just one of many and in this one we've got drop threads down here and pump and freeway valve here what can happen here then when this fills back up definitely you would get an air lock round to the hot water system there because there's on that drawing anyway no automatic air vent to let the air out so that's gonna lock up for sure also when this goes around to the heating system here to radiators check the freeway valve here now there's no automatic air valve there either so this bit here could air lock up a way to get it out there may be an elbow on there or it may not it might be a soldered one in which case you're kind of stuck what you do is undo the nut on the freeway valve just a couple of turns not right off and just loosen the pipe out and then you'll be able to crack and get the air out of there and then do it back up that's always a firm favorite for air locks the freeway valve also the pump when it's in a vertical position doesn't normally get here but it's still worth undoing the front screw that faces you and just see if there is any air in there at all and get it out because that quite often just locks in the head part of the pump there raiders but over on the drop can always be problematic because these ones will always go you might find these don't simple solution again shut the rads off upstairs lead the ones open downstairs and force the heat around to the bottom ones usually then it pushes the air right around and back out and about the vent if it doesn't know and sometimes you find that you're still getting those rads hot but not the bottom then it's worth putting a hose on one of the feeds here on the drain valve and emptying it outside with the heat and running but just very slowly to pull the air down those pipes and out and run it out the hose outside that sometimes works well as well worth a try if you're really stuck this fne system here as you can see another likely culprit for air will be here okay on these motorized valves again because there's no air stalk sticking up anywhere on this line it's probably going to air look behind on these valves again just undo one side and see if there is any air there just pull the pipe out slightly you'll get water so make sure you got some towels under it and just do it back up again and you should get the air out ideally there should be an air valve here sticking up but they've decided to take their bent this way around which does mean that you can still lock up again this is a drop system those two radiators any problems down there do as i just said before shut them all off and leave just one on them maybe the other ones if you can force it through and up and if you can't then again stick a hose pipe when the one isn't going whether it be in this instance if the air is in this line it would stop both of them and you could just run it out leave the heating on and running and just put your hands on these two pipes and you'll feel the heat drop down but that's the flow there the red ones you'd feel it drop down into the radar and as soon as you feel it's done there then shut the drain valve back off another one then let's have a look at this one and as you can see our motorized valve is there and our pump here now pumps on horizontal could get air in it that's sometimes worth undoing that side on the other side of it it says in the air there and our motorized valve could get here just one side of it worth checking it should be okay on this system because it looks like it goes up to flow there and there's a vent on this one going up so you probably find that would be all right on this particular one if the vent wasn't coming off of there then definitely you would probably get air somewhere there if it was running without and then coming up onto that pipe there so worth checking again also on this it probably get an air lock in there on the flow into the hot water system there's no vent there should be a little bottle vent on the end of that so the air doesn't get locked in there okay so that's another potential one again we've got rads downstairs quite a lot off of this particular run so we're going to make sure these two drops here are clear there's no vents on the top of these bends so it could get an air lock there it might have to be pulled out again so same scenario lastly then combi system and just to show you i'm not totally immune to getting air in the system as well i'm afraid because once it's drained out obviously there's air in it but when it fills up obviously you're pushing a lot more pressure through from the filling loop and generally the air does come out but sometimes i've known unlike on this particular one here a downstairs rad not go again fairly simple just shut the other ones off upstairs and leave that one open and it will push it through generally airlocks on combi systems are not so frequent you've really got to have a really badly plumbing system to get air in there on those instances but just to show you're not immune there we are then that's about my take on getting air out of central illinois systems when you want to flush them all out give them a clean out especially now springs come in and summer and you won't need to heat on now a little while once it gets warm it's good time to actually do those jobs clean out the heating system and put some fresh inhibitor in there and you can try it anywhere over the summer can't you and just make sure you've got no air problems in there and it won't affect anything because it's not cold weather good time to do it spring cleaning okay that's about it though all my stuff you know i know derek and verdi catch again guys bye

Channel: dereton33

Views: 47,791

Keywords: air, central heating systems, airlock, central heating not working, flushing out heating systems, plumbing, plumber

Id: GdB9GEJCjCI

Length: 9min 47sec (587 seconds)

Published: Wed Mar 24 2021