Suburban Furnace Troubleshooting - Motor Replacement February 16, 2019, 01:23:27 am I'm guessing it's fan bearings?It's a fairly consistent rumble noise.Any other ideas?It's an old heater (1995).Are these fans replaceable?
Re: A low rumble in the heater Reply #1 – February 16, 2019, 01:44:20 am If you mean the furnace, a single motor drives both the induction fan and the circulation fan blades, so bad motor bearings will involve breaking the seal to the combustion chamber. Properly resealing after repair or replacing the motor can be risky, since any leak can let combustion fumes enter your rig.Steve 1 Likes
Re: A low rumble in the heater Reply #2 – February 16, 2019, 10:30:07 am Quote from: tedeboy - February 16, 2019, 01:23:27 amI'm guessing it's fan bearings?It's a fairly consistent rumble noise.Any other ideas?It's an old heater (1995).Are these fans replaceable?Are these fans replaceable?Ted, did you do a Google or other search for your make/model of furnace? Parts diagram?Chris 1 Likes
Re: A low rumble in the heater Reply #3 – February 16, 2019, 12:01:40 pm Quote from: Chris Horst - February 16, 2019, 10:30:07 amAre these fans replaceable?Ted, did you do a Google or other search for your make/model of furnace? Parts diagram?ChrisNot yet.
Re: A low rumble in the heater Reply #4 – February 16, 2019, 12:40:35 pm Steve is correct, to remove the fan will require breaking the seals on the combustion chamber.It must be reassembled with new seals, preferably by an experienced tech. A failure to completely seal the chamber could exposed the users to carbon monoxide gas.The motor should be available and look something like this.Suburban 233101 RV Furnace Motor for SF-20, 25, 30 / SF-20, 25, 30FLarry
Re: A low rumble in the heater Reply #5 – February 16, 2019, 04:38:11 pm Ours has a low rumble also, I would kind of think that motor bearings might start to squeal on you at first start up. Our rumble I'm sure is the burner. A couple things could cause our noise, number one being gas pressure too high. Ours always works so I'm good with the noise.For sure you are going to have to pull the furnace to replace the motor.
Re: A low rumble in the heater Reply #6 – February 17, 2019, 02:41:20 am We believe our bearings are bad - we get a loud squealing nose and the forum members all thought it was fan bearings.. If I remember right Roger listened to it at Quartzsite 2018 and seconded that opinion.It is an ear splitting squeal, went from just a little squeal to ear splitting in just a few days of use. No way to imagine the nose was a rumble if any kind.We just ordered a new motor that should fix this - we have a model nt-20se (took off the inside faceplate and found the metal label with info) and just ordered Amazon.com: Suburban 520950 Old Motor: AutomotivePlenty of YouTube videos on replacing the motor - tons of screws to remove and small wire bundles to unclip and the gas line gets a nut turned to disconnect/connect it - with leak testing done after it is connected. Looks tedious but easy to do if you have installed appliances before.JaneSent from Yahoo Mail for iPhone As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.
Re: A low rumble in the heater Reply #7 – February 17, 2019, 02:45:47 pm Quote from: JonS - February 16, 2019, 04:38:11 pmOurs has a low rumble also, I would kind of think that motor bearings might start to squeal on you at first start up. Our rumble I'm sure is the burner. A couple things could cause our noise, number one being gas pressure too high. Ours always works so I'm good with the noise.For sure you are going to have to pull the furnace to replace the motor. I was told that the burner could be dirty. Now I just need to figure out how to clean it.
Re: A low rumble in the heater Reply #8 – March 08, 2019, 11:12:27 pm We replaced our heater motor - had a NT-20SE. No more squeal, works great. Taking things apart was difficult as the instructions didn’t match our furnace, neither did the o e YouTube video we found so it was figure it out as we went. I will post steps and pics soon.But now it has a low thumping noise when furnace (not just fan) is on. I would bet the burner needs cleaning and it needs a general servicing.Ted if you found your burner let me know where.If you have not yet started working on it, to take ours out of the wall to work on:Ours got removed out into the coach,The front grill is held on by screws,Just inside that front grill is two screws going down into the floor.Also one screw going up into the wood above the heater,On outside of rig there is a 5 1/2” screw that went from the exhaust (middle of top circle) into the furnace,.Propane connection was inside the front right bottom corner - reasonably accessible. Burner likely the next component or two after that propane connection. Now furnace can be pulled forward some if your wires have extra length,Wiring came out the right side off he heater, about mid height, about 1/2 way towards the back’ of the heater (for us easily accessible by taking out the drawer over the heater).There is an additional screw inside the front on the right side that I believe can also be removed to give easier access to the circuit board and burner.Jane 2 Likes