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Topic: Suburban Furnace Troubleshooting - Motor Replacement (Read 313 times) previous topic - next topic
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Suburban Furnace Troubleshooting - Motor Replacement
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?
2021 Mid Bath
Re: A low rumble in the heater
Reply #1 –
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
2004 FL
2013 Honda Fit
Re: A low rumble in the heater
Reply #2 –
Quote from: tedeboy  - 
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?
Are these fans replaceable?

Ted, did you do a Google or other search for your make/model of furnace? Parts diagram?

Chris
Formerly: 2002 30' IB
Re: A low rumble in the heater
Reply #4 –
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, 30F

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: A low rumble in the heater
Reply #5 –
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.
1994 MB
Re: A low rumble in the heater
Reply #6 –

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: Automotive

Plenty 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.

Jane

Sent from Yahoo Mail for iPhone

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Jane & Scott
Currently have a 1989 TK  LD we did a lot of upgrades on.
Bigfoot 25RQ Twin on order with early summer 2024 ETA

Our smartphone autocorrects into very poor English.
 We disclaim the illusion of ignorance this creates as we have enough ignorance we rightly claim.
Re: A low rumble in the heater
Reply #7 –
Quote from: JonS  - 
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.
I was told that the burner could be dirty. Now I just need to figure out how to clean it.
2021 Mid Bath
Re: A low rumble in the heater
Reply #8 –
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

Jane & Scott
Currently have a 1989 TK  LD we did a lot of upgrades on.
Bigfoot 25RQ Twin on order with early summer 2024 ETA

Our smartphone autocorrects into very poor English.
 We disclaim the illusion of ignorance this creates as we have enough ignorance we rightly claim.