Top 10 Circulator Pump Problems Found on Boilers!

hey guys this is Craig me who I trade with EC silverstack and today we're going over are the top ten problems that occur with circulating pumps used for boilers problem number one is if you have air in the lines and it's actually not the fault of the circulating pump so the circulating pump could be running just like this so I don't know if you can hear that that noise right there you could actually put a stethoscope on the end of this or you can listen in with a screwdriver to allow transmission of that noise across the screwdriver over to your ear you would definitely not want to use a screw driver or anything like that if there is exposed parts that we're turning but everything's internally moving inside this pump right now and you can tell that the that the circulator pump is running where at least that the motor is running so then comes the problem of having to purge the air into the lines so in order to get the air out of the lines most boilers are going to have an automatic air bleed so such as this so as long as this calf is loose it's gonna automatically get the air out of the system if you find that this cap is tight on the boiler there may be a reason for that and that may be because the the valve at the top right here may be leaking water out instead of just purging the air and then stopping so in that case you may have to replace the the valve core in the inside here or go ahead and replace the automatic air bleed some are not fitted with a valve core and they just have a a piece of rubber that blocks the port but basically just valve that off take the pressure off and then you go ahead and replace this you could also have a venti that's inside the baseboard and basically at the top here you'd have either a Schrader valve or you'd have a key valve and when you what you do is you loosen that up if it's a key valve and it lets air out and water until you get a steady stream of water coming out then you go ahead and tighten it back up or it could just have a Schrader valve in it so so that's something that you could use to get the air out of the the lines up at the high points of the baseboard radiators you could also use your boiler drains say you have a boiler drain on the supply side in the boiler drain on the return side and say maybe have tsums what you can do is you can open up one hook it to a hose and then attach this to your cold water and you can force cold water through with the other boiler drain open and then base we are going to allow air coming out and you're going to allow the water coming out until the gurgling of water mixed with air stops so you just have a steady stream of water so you do that for each zone until you have all the air out of the lines you want to make sure that you don't exceed the max pressure while you're doing that on the system because you don't want the pressure at least to blow the other thing that you could do is if you have a boiler drain on the opposite side as the where the cold water feeds in you have this backflow preventor and pressure reducing valve you can just allow this to push the water in and then vent the air out of the other side with your boiler drain until you have a steady stream of water when you're done purging the air out of lines you want to make sure that you're back down to 12 to 15 psi G with a cold working pressure on that boiler when the boiler is hot it's probably gonna be around 18 to 22 psi G so this pressure reducing valve is what allows water to feed into the system to keep it at a steady cold water temperature of 12 to 15 psi G Robin number two could be if you have some type of a blockage in the system and it's not allowing the water to flow freely so that could be a manual valve such as one of these right here it could be an automatic electrical valve or it could be something like this and this is a mixing valve and on the sides of some mixing valves you're gonna have a screen inside and that can end up getting clogged up so this is a washer with a screen a lot of newer ones don't have those but some do and so that can end up clogging up problem number three is if the motor is stuck and it's just not turning the impeller inside so this is probably one of the most common issues is when the bearings end up seizing up inside the system so this circular pump are going to take an amp draw and this one is working and then we're going to take a AM throw on another one that is not working so we have our ECM clamp clamped around one wire and it's reading 0.65 and also realizing that there's no load in here right now as far as the water goes this pump right here on the rating plate states 0.71 amps so this motor right here is stuck in is not turning the impeller will not turn and unfortunately there's no access in order to try to help it turn but that also means that the bearings are very seized up inside and they're just stuck in place so let's go ahead and take an amp draw and you can see that this amp draw is right about twice as much as this one was running it it's actually a little bit over that but it's at one point three five amps right there so you can actually hear the difference between a running pump such as this one right here and a non running pump so there is no water sloshing there's no noise at all other than just a humming noise because the windings are basically overheating and it's not working properly the rotor is not turning in reference to the crew and foss bumps you could use either a very wide screwdriver or you could use a quarter I like to use a pair of vise grips and then you can go ahead and turn it like that or you could also use the screwdriver with the vise grips just in order to press downwards and then you can go ahead and turn it like that but you don't want to use a thin screwdriver because you're going to end up marking up or bending this the screw right here and possibly damaging it and then not being able to turn it as you can see somebody has already done that on this screw so you can see in the end right here and you can actually get to the end of the rotor in order to see if it's going to turn or not so if it's if it's real hard or something like that and it's not turning very well that could be an issue right there or if it's just not turning it all and it's completely stuck so this right here you can get to from the end and also if you took these four bolts off you can get to the full rotor assembly in order to be able to turn them so you gonna notice a rubber o-ring right here and that is actually holding the water in there because water does come into there in order to help the sleeve bearings operate so you want to be aware of that before opening this up now show you what this one looks like in a second because what we'll do is we'll unscrew these four bolts right here and we'll be able to take this motor right off of here and we'll be able to check the impeller on this right here you should have valve somewhere as close to the circulating pump if you need to replace the motor instead of the actual pump housing but on these water will come out when you go to replace that motor right there so you want to go ahead and valve off on both sides so go ahead and unscrew these they're not going to be that that tight so you should be able to get them loose fairly easily you have to unscrew them all the way out I'm just breaking them loose right now now this just fell apart but just one tap with a flathead screwdriver and this should come apart and as you can see right here we have our impeller and it is not turning at all okay so it's it's frozen solid so that's your bearings and your sleeve right there or holding on to that axle here's another one right here and you can see that this one spins freely so if you have the circulating pump out such as this right here you can just go ahead and take a screwdriver in there and see if you can push on the empower and see if you can get it to spin so as you can see it's fairly easy to replace a circulating pump motor off of a circulating pump flange such as this so what you want to do is you want to go ahead and valve off before and after the circulating pump and then under your four bolts you pull this off and you want to replace this little o-ring right here then you bolt your new one on and then you got to turn your electrical power off and replace your electrical wiring and then you're ready to go and then you can go ahead and turn the system back on again so after you replaced the motor if you get your water level all the way up to here then all you have to do is purge this amount of air out versus this amount of air that would be a lot harder so it just depends on where your air bleeds are at in the system as far as how hard it is to get your air out now you could have a larger circulating pump such as this and you have bearings multiple bearings that you need to wheel on this twice a season so right here is an oil port here's an oil port and here's an oil port and either the motor could go bad or you could be over here in this assembly where the the motor attaches to the impeller acts a lot so any of those bearings could be the problem but they do have to get wheeled on on a circulating pump such as this problem number four can be if you have something jammed up inside the impeller area so something could be breaking loose from inside the system and in this case you see it is a rubber o-ring that's stuck in the impeller in there so that would stop the motor from turning or stop it from turning as quickly so that could be an issue as you can see the impellers are not tight up against the inside of here so it really takes something large in order to stop this from from turning so there's a lot of free space in there so this is more of a rarer instance but it's still something that can happen problem number five is if you are leaking water out of the side where the motor mounts over to the impeller flange assembly so as you can see right here there's a rubber o-ring rate along the inside here sometimes it's set back in this instance it's right along the edge and on this one you can see that the water was leaking outside of it and you see that this rubber o-ring right here had fallen off and broke so this can happen just due to that the each or the titanosaur or something like that and you just need to replace the o-ring itself another thing could be just that these screws are not tight enough and that could have been the problem the same thing on this circulating pump do you have a gasket right along the inside here and that could have worn down or the the bolts may not have been tight enough so it could be leaking water out of there you could also have a problem such as at these gaskets right here and right here these would be outside of the pump assembly but what could have happened is maybe one of these bolts and that's where tighten down to hard compared to the other side or maybe this got squished and cracked over time or maybe the cast iron cracked and broke because the the bolts were too tight or maybe the nut has loosened up over time so that's a variety of things that that could allow water to leak out of this gasket area problem number six could be that even though your thermostats calling for heat you may not have power getting to your circulating pump so you could have incorrect power or no power at all to your circulating pump and that's why you don't have any hot water so on aqua stat relay such as this these contacts inside could be pitted so when this is calling for the circulating pump to run to circulate your Heat it's supposed to suck this relay down and these contacts become pitted and sometimes you'll have a high resistance value across them and then you won't have your power coming in here and going over to here so this this relay right here is stopping your hop from connecting to the hop that comes out of this aqua Staten goes to your circulating poem you can also have something like this and this is a zone control relay right here and the circulating pump is powered via this end switch down here so the switch is exactly what it is it's it's a switch it's a normally open switch so that's the extra end switch and this is the main end switch so you come into here with power and you connect it to your transformer so that this board can be powered first of all then you have a power coming out and then going over to this switch and then coming out of the switches the hot that goes to your circulating pump and so this switch will not close the electrical circuit until the thermostat calls so you have 24 volts going to a thermostat coming back to the board right here sending a call for heat then you have your zone valve you see 2 to 3 either has to have continuity or 3 to 4 has to have continuity in order for this board to send power there to the circulating pump that confirms that the zone valve is mechanically open and the water will flow if your circulating pump turns on so you can have an issue with this you could have an issue with bad contacts and your aqua stop or just the aqua stat itself is not sending power over to your circulating boat but you can measure for your voltage right here by turning your multimeter on to voltage and then you can put one probe in one wire nut and one on the other one in order to read if you're reading 120 volts or not problem number seven could be if the motor electrical windings are bad so a way to check that is you just turn the power off you disconnect the electrical wires and they can check the resistance value of the electrical motor windings so right now right now we have the multimeter set on ohms and we're reading 42 2.2 ohms of resistance so if we read oh well like we do right now then that means that the windings have burnt apart likewise if we check right over here to the ground we should have no resistance whatsoever if we did and that means that the motor windings have burnt apart and are touching the the metal ground frame so you can see that that motor is good now just because our wire is connected to the capacitor it's in a buck connector you don't have to cut that out in order to check your resistance value we are checking the true resistance value right now of 42 ohms it's taking the path of least resistance that's why it's not going through that capacitor so I'll show you that so on this one right here the buck connector is cut out and you see that we're still reading roughly 42 ohms of resistance on this one is reading 41.3 ohms so this motor is good problem number eight could be a bad capacitor so what I did to replicate that as I unwind this from the buck connector between the black wire the red wire and the white wire so this is disconnected and we're gonna go ahead and put our our multimeter on our hot wire right here and it's set on amperage right now and we're gonna go ahead and turn the power on and see what happens when you have either a back capacitor that where the capacitor is not attached to a PSE motor for a circulating pump so right now we're reading 1.5 amps and we do not see the impeller turning so this is the same ampere treating we read when the bearings were locked and the capacitor was good now the power is off I'm going to go ahead and wire this black wire right back in and then we'll go ahead and turn the power back on and now you see we're only drawing 0.7 amps and the motor is running so in order to test the capacitor you want to shut the power off and go ahead and disconnect the wires and then what you do is you cut the buck connector that was connecting these three wires cut that out and then you can go ahead and take your capacitor wire in order to read the UF reading on the capacitor you have to short the capacitor out so you take this wire and you touch the other end of the wire down here and once you do that we can go ahead and read it with our multimeter so we're going to turn our multimeter on and we're going to go ahead and hit the Select until we get to UF so then we take one probe that has the alligator clip we'll connect it right on there make sure it doesn't touch any other wires and then we'll touch the metal part where it's connected down there in order to get our MFD reading so on this one we're reading 2.01 and on the capacitor it says it's a 5 UF so the motor may run but it's not as healthy for the motor to have this capacitor in place because this this is definitely less or actually it's it's more off than 5% so it's it's less than half of what the rating is now go ahead and short this one just like we did the other one so we just go ahead and touch this wire down in here and then we'll put our alligator clip on and make sure our probes are not touching anything other than the wire and you see that that one's reading 4.9 2 3 so that one is good that's within 5% of the reading so it's the same same reading on this one says 5 UF plus or minus 5% problem number 9 could be if the axle is broke off and so that the motor rotor is not connected to the impeller so you know this is the inside rotor assembly that goes inside the stator and this is inside of this motor so what could happen is this could end up breaking so you see that this should not be able to turn as this turns these these stay still and this should turn just like this and that's how it works so you see that now though that this is broken on the inside here so that could happen so this right here is not metal on these you see this right here it could just snap so that could be an issue now on a pump such as this right here you could have separation between the motor and the impeller so if you look in here you'll see the coupling that attaches both axles right there and you see the springs that are attached now you could have the rubber mount inside going bad and and basically breaking the the coupling assembly because the axles are out of line or you could have a weak spring or something like that and they snap and then it's no longer connected so that could be the problem so you just rectify that by taking these bolts off in order to replace the coupling assembly and possibly the rubber mount inside problem number 10 could be a loud noise coming from your circulating pump now it's typically not from your impeller it's typically from your bearings unless you hear water gurgling or if that's the kind of noise but if it's a squealing noise it's typically the bearings inside inside the the motor assembly now in this case right here these have to be oiled so if you don't wheel these bearings those bearings are going to deteriorate and you're gonna hear a squealing noise from those if you hear like a chattering noise something like that that could be from the coupling assembly that's inside of here so that wouldn't need to be addressed if you're looking for the multimeter I use in the video or the other tools I use out in the field I have them all linked down in the description 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Channel: AC Service Tech LLC

Views: 181,840

Keywords: acservicetech, repair, maintenance, how to, fix, hvac, hvacr, how do you, test, ac, service, tech, check, measure, read, superheat, subcooling, relay, zone, valve, air, noise, troubleshooting, diagnosis, flange, replacement, motor, leaking, stuck, hot, water, baseboard, venting, purging, taco, b&g, sentry, bell, gosset, 007, impellor, impeller, bearing, sleeve, pressure, capacitor, electric, voltage, pipe, tube, cast, iron, coupler, coupling, operation, making, sizing, gpm, radiator, hot to touch, tankless, heater

Id: qJ5LZKlEks8

Length: 20min 11sec (1211 seconds)

Published: Thu Feb 28 2019