Why Is My Mobile Home Furnace So Loud?
Mobile home furnaces are loud because of the openness of the furnace to the living area and excessive air velocity through undersized ductwork.
In most manufactured homes, cold air returns are virtually nonexistent. Not enough return air ducting is the main problem with manufactured home furnace noise.
The small warm air supply duct system increases air velocity and noise, like blowing through a straw. That’s how your furnace feels.
I realize that not all manufactured homes have the same type of heating system. The furnace in your manufactured home may be configured or installed quite differently. I am writing this article to describe the mobile home furnace installations I have experienced. I hope you can use some of my ideas and experience to make your system quieter.
What To Do If Your Furnace Is Making Noise
You can fix a loud manufactured home furnace yourself or hire your local handyperson to install a larger filter relocated above the furnace and a door over the furnace closet.
The door is a straightforward DIY project. Buy a nice-looking sheet of quarter-inch plywood and cut it slightly larger than the furnace cavity.
I’ve done some research and have been in many manufactured homes. These mobile home heating systems are almost all noisy enough to affect your TV volume.
A manufactured home furnace is too loud when you have to turn the volume up when the furnace cycles on and turn the volume down when the noisy thing goes off.
Or maybe you want to quiet the furnace down. Above is a mobile home furnace with doors and a filter grill removed. Even with the furnace doors on, there is nothing to block the noise from the furnace.
Cut the plywood to completely cover the furnace compartment. Then, fasten the cover over the opening. Remember that it should make a good seal to keep dust and pet hair from seeping in through the cracks.
These filter grilles are available on Amazon (ad). I could only find them to fit a one-inch thick filter. You can make up for the problem of having one of those flimsy one-inch filters by purchasing a thicker filter made to fit into the new filter frame.
Installing a filter grill just above the furnace takes advantage of the void above your furnace. The cover over the front of the furnace creates a chamber that will help reduce the noise. Keep the filters as large as possible to allow for the best airflow and more prolonged use of filters between changes.
By assessing your system, you may find it easy to get the return grill even further away from the furnace for quieter operation. Remember, it has to seal completely around the door. This includes the bottom of the door. This door is easy to remove with sheet rock screws. If you are a craftsman, build a more appealing door.
If the door doesn’t make a good seal, it won’t take long for you to notice dust collecting around the door.
Dap makes a great product called Seal ‘N Peel. You apply Seal ‘N Peel like any other caulk, and when you need to remove the door, it will easily come off without much effort.
| Dap 18354 Seal ‘N Peel Removable Caulk | Amazon |
Be sure to use a thin bead of white or clear caulk (or Peal ‘N Seal) and paint the door to match the surrounding wall.
In my research, I could only find filter grilles that hold a one-inch thick filter. You can take advantage of a one-inch filter grill by ordering a 5″ thick filter from Amazon (ad) with a lip that fits into the filter grill, and the bulk of the filter fits nicely into the cavity.
| 20x20x5 Practical Pleat 5″ Return Grille Air Filter – MERV 11 | Amazon |
A standard filter size that works best for the average manufactured home is 20 X 20 or 20 X 25. Be sure you buy common sizes, as it makes it much easier to find replacement filters.
Let me show you how to do this and how much it should cost.
Remember that any work you do to change the airflow or alter the duct system should be checked by a qualified technician to ensure no damage to your heating and cooling system will occur.
Manufactured homes come with the poorest air filter systems from the factory. Most furnaces have a little slot to slide in a one-inch filter relative to the depth and width of the furnace. It’s just never good enough.
Furnace manufacturers install filter slots in their equipment because installers take the cheap way out by not adding sufficient filtering. This includes manufactured home manufacturers.
When you remove your dirty furnace filter, a small amount of dirt will fall onto the fan. That dirt then gets blown into the ductwork. After several filter changes, that small amount of dirt makes for some filthy ductwork.
And some types of furnaces have their filters crammed into the furnace door. I often see this with gas furnaces in manufactured homes—another poor solution for home air filtering.
A better filter system keeps the dirt in the filter and then in the garbage, where it belongs, and improves the air quality and the noise.
And, no, you don’t have to buy a new furnace. You can make even an old relic sound so much quieter. It may even be a great little DIY project. You’ll be much happier when you can leave the TV volume at one level.
Specifically, this applies to electric furnaces, with or without cooling units or heat pumps, and in only certain types of furnace closets. The furnace closet should be for just the furnace with no other appliances, but this can be done if the electric water heater is in the same space.
If your manufactured home furnace shares a space with a washer and dryer, modifying your project becomes a little more challenging, but it can still be accomplished. Once you learn my idea of closing off the furnace, you can figure out how to complete the project.
If your manufactured home furnace burns gas or oil, certain issues with combustion air enter the equation, and making your mobile home furnace quieter would be hazardous. Consult a professional before taking on this project.
Fossil fuel furnaces with two PVC vent pipes or a concentric venting system should qualify for enclosing the furnace. Be sure to consult an HVAC professional before enclosing a fossil-burning furnace. You can google your furnace’s model number to determine the venting type or send me pictures.
For your safety, I’d consult someone familiar with combustion venting to see if my new filter method applies. Along with the inherent noise in these furnace installations, you should first determine if the noise is something other than normal fan and air movement through the system.
Blower noise can come from a bad bearing or a wheel rubbing on the fan housing.
Another obvious source of noise and rubbing noise could be the fan motor bracket. A loose or broken bracket will cause the wheel to rub the housing.
Use caution when reaching into tight places. Not long ago, I reached into a blower motor compartment to see how hot it was and slowly removed my hand. Without even so much as an ounce of pain, I had cut open my hand to the tune of 9 stitches. There are some sharp edges inside these furnaces.
Many homeowners ask what the cost of replacing a furnace blower bearing is. Even if you could find a motor repair shop that would repair fractional horsepower motors, the cost would be more than that of a new motor. Then consider that after you pay for the new bearings, you still have the windings and wiring of an old motor that could short and burn.
Changing the fan to a lower speed is possible, even more so with just an electric furnace. A heat pump requires a certain amount of air through the indoor coil and should be at high speed. Not enough airflow could be detrimental to the compressor.
Most fan motors have 3 or 4 speeds. An electric furnace without a heat pump attached can run at the lowest speed. A good service technician can determine this for you. If you have any doubts, it’s well worth a service call to make sure.
Another noise created by these poor duct systems is the warm air supply vent closest to the furnace.
I don’t advise my customers to block airflow in HVAC applications, but there is one vent that I do recommend closing. It’s the supply vent right near the furnace.
The air from these vents located next to the furnace does very little to influence the room temperature because it short cycles right back into the return.
Pull the vent cover off the duct, cut a piece of cardboard to fit the bottom, and tape it on. The better seal you make, the more noise reduction you will notice.
Conclusion
An apology: I didn’t realize that some folks don’t like their manufactured home being called a mobile home. I couldn’t change the title for technical reasons (which I don’t fully understand), so I changed all references.
It’s a shame that the manufactured home industry won’t add simple ideas to reduce noise pollution and improve filtering. It’s a tightly budgeted housing segment and provides an inexpensive way to own a home, but I can’t help but think some ideas could be offered as options.
The filters available for the slot in the furnaces that come in any home are insufficient. They only lead to more maintenance or more repairs without maintenance.
If you’re asking yourself how to replace a manufactured home filter, consider replacing the type of filter and the location to help reduce the noise and increase the filtering capability of the forced air system.
Chad: my Coleman mobile home gas furnace makes a slight thump sound when the system shuts off after heating; sounds like a vent closing.
Is this normal?
Paul, sounds like a motor. As these motors get older they tend to sort of bump when the shut down. If you can get your ear closer to the fan assembly with the door off you can possible determine the location of that bump. -Chad
I have a double wide Coleman oil furnace. Recently the blower goes on and off much more in short cycles then I remember ever hearing. I asked my furnace guy if it was possibly the blower limit switch sensor ? He came replaced it with a miller switch couldn’t find a Coleman replacement. But it still seems not quite right. Any suggestions please?
Angelina, I would call your furnace guy back. He should stand behind his work. I just don’t have enough info to give you a good answer. It’s one of those “have to be there kind of questions” Sorry – Chad
Is it ok to leave the vented utility door closed to not hear my intertherm furnace. Will it cost more to operate closed or wear out the furnace quicker ? This is in a 2021 double wide.
Jack, You said a vented door? In that case the home was designed to have the door closed and it shouldn’t effect the operation of the furnace. Chad
Hello, we just had to have a new furnace put in our modular it is way louder then our old one that was 26 years old ? You would
Think technology would be better . But help it is so loud I can’t sleep at night and the tech says there is nothing else I can do he has it at medium speed and I can’t block the vented door with insulation cause of the air flow and the space is to small for duct work. Is there anything I can do to make it quieter Spent 4500.00 and can’t even use it been using space heaters cause it’s to loud.
Tina, is this a gas or electric furnace. Shoot me a picture at homeheatproblems.com and that will answer a lot of my questions. Chad
Hi Chad
Just came upon your site thank you so much for letting us mobile home owners in on this. My furnace is so loud have to turn the volume way up on tv then down then up so frustrating and as you can see right next to my bed I have a 2016 Kars mobile home May I please send you a picture of my furnace to see if this would help? Please and thank you.
Carol, I installed a plugin on my site that should allow you to send a picture. It’s in the comment area. Let me know if it’s not working.
Chad,
Thank you for posting this. I would like to send you pictures of my unit, to make sure this could be done to mine. I think it would work perfectly but I’m not completely sure.
Brook, I’ve just installed a plugin on my site that should allow you to show me an image. Lets see if this works. Let me know if it doesn’t appear or function properly.
Chad –
Is there any way to send pics to you? My manufactured home is a 2018 Champion and my only complaint is the furnace as well! The pic you posted above looks nothing like mine. I would love to hear your advice on how to muffle the noise for mine.
Thanks!
Bonnie, I have your email. If you give me permission I can email you and the you could send me pictures. – Chad
Hi Chad I have a question I have a Miller gas furnace it about 2 yrs old recently during this heating season it has been getting louder and louder. It’s an odd set of noises. It start with aclick then goes to a rattling kinda stutter immediately does this for a 30 secs to a min then you’ll here a click click sometimes a slightly louder click click not quite a boo but getting close.. I noticed today that there is a slight crack on the back of the flue pipe where it connects at the inside top of the furnace slightly bent I presume on the collar. Shifting I’m guessing is the cause but could that be the cause of the rattling studder. It also is starting to short cycle a little bit when it’s cold and has to run more . Makes that noise from start to finish and sometimes clicks during blower and heating are both running. I guess my question is can I fix the pipe with HVAC tape and can I also in stall filter on my laundry room door as well as on the furnace to quite Down noise furnace is direct vent sloted doors on both furnace is cramed in a hole in the wall of the laundry rm and water heater is directly next to it but out side the home horrible air quality as well?
Tricia, I’m assuming you have a 90% efficient furnace venting with PVC pipe but 90%’ers are not too common in mobile homes. Afraid I don’t have enough information. Is the crack leaking any condensation (water)? If it ain’t broke (leaking) don’t fix it. Fittings should be replaced and not patched. It sounds like you need a service call to find out the source of those noises.
No it’s a 80%effincent 88,000 btu down flow of course. Metal pipe heading straight up to the venting that goes through the roof and vent out at the roof I would post a pic but no option for that. It’s a small spot on the backside.
I’ve been looking for a way to share pictures. Sorry I don’t know how to help you. The noises still seem to need a service call.
I have a 2019 mobile with an Intertherm furnace. When it first comes on it’s ok but once heated to set heat it goes off briefly & comes back on very very loud & all the vent pipes rattle, goes on thank god for less than a minute but you cant hear tv or talk to others in the room. Is there something wrong with it?
Jerri, That is odd. I would have it checked out. Let me know what you find. Wish I could fix it for you.
Chad
Hi Chad:
2 problems with Miller mobile home bottom flow oil furnace.
1.) Furnace is located too close to the bedroom, so it gets way too much heat, and the living room starves. I’ve been advised not to close off vents, so here is my idea: Put fans in the 2 main living room ducts where where heat enters the room. Connect remote on/off switches wired to the furnace fan motor.
Then I got the bright idea; what if I put a timer in the in the line so that the living room fans would not function from 10pm to 8 am. (There’s about a 6 degree difference between the rooms).
any thoughts?
I can’t get in the crawl space to look for leaks, but it is well insulated.
OK. Issue 2. Hollow noise when it starts up and only lasts for 3 or 4 seconds. Also, at times, just before the fan starts, there is a a quiet grunt and 2 second pause before starting. From the old days of car capacitors, I’m thinking that the capacitor is bad, and there is probably a fan (replacement) issue.
I asked my oil supplier’s service guy when he was doing my bi-annual checkup what could be done. His response was that’s just the way mobile furnaces are. Noises are normal. I lived here when this furnace was installed…..It was nowhere near that noisy.
Any ideas would be appreciated.
Leonard,
1. not much you can do about the poor location of the furnace. But consider adding a ductless heat pump to the main living area and the oil furnace would become a backup heat source running only in the coldest weather. I love spending your money, right?
2. Not sure of your skill level when it comes to replacing capacitors, but if you follow safe procedures like turning off and making sure the power is off then changing a cap is rather simple. Be careful probing around inside a fan compartment, I’ve acquired a few stitches from sharp metal objects in those areas.
Best answer would be to hire a tech and check out that motor. If the fan spins freely and the bearing seems good it’s just a hard question to answer without the right tools. I’m not an oil guy. Spent all my time on gas and electric heating.
Good Luck
Chad
Hi,
I am in Vancouver, British Columbia Canada.
My tv has to be put on almost full volume, when the furnace starts, and I am in a older double wide mobile home.
I thought you had my answer, but ours is the natural gas version, and is the only furnace allowed with current regulations.
Do you know anyone or company locally, that can help with noise of the natural gas Coleman, with noise reduction safely?
Thank you.
Great Column, thanks for great explanations.
Kb, I wish I had an answer for you. Don’t know a soul up there. The combustion furnaces are a real problem. They work well for warmth but the noise is real. I guess you’re just gonna have to ask around.
Good Luck
Chad
Hi Chad, thank you this great post. It’s exactly what I was hoping to read. Could I send you a picture of what my furnace and filter system currently is set up like, so that you could let me know if I might be able to pursue the option you first mention?
Certainly. Use the “img” icon above. If that doesn’t work we’ll go the plan B
My furnance is about 20ft in the hall ,it has no door except the furnace itself and is so loud I have to turn volume up on my tv when it comes on. My manufractured home is only 2 yes old ,always been loud. Would a door make a difference?
Thank you
Carol
The combination of the door and filter grill can make a noticeable difference. Additional noise dampening material in the right places can help even more.
Hi Chad I presume this is the right way to communicate with you I recently moved into brand new double wide Mobile home in Southern California with AC unit in the middle of the home in the laundry room When the fan blow is Very loud I watch the solution on the website but my unit it’s little bit different I can’t see a way to send you a picture of the units. There is anything I can do about it? thanks Aaron
Aron, when you reply to this their are boxes directly above your typing and the one labeled “img” will allow you to send an image. If that doesn’t work you can always look me up on Google maps. Chad Peterson Prineville
Thank you Chad I will try
We have a brand new cavco single wide mobile home (Embry) with a propane furnace and piggyback AC unit. The unit when running AC is very loud. It is located just as you enter the home. Nortek model MG1E-056F1AAM1. There is a furnace door and a small vent above the furnace 11.5 wide and 5.5 long. The furnace has Louvers.
Hi Sharon,
The AC is most likely louder because the fan runs on high speed. Not much you can do about that unless you enlist the aid of a service tech to see if that will run ok on a slower speed.
Thanks. When ac starts it is like a airplane taking off. dB reading of 101 and then goes down to 96dB.
Sharon, I hope my ideas fit your situation.
Chad, I like Sharon purchased a 2019 (built – custom, my own design) CAVCO. It’s a double-wide and 1,922sqft. The salesman convinced me to get 9′ ceilings. To heat/cool is costing me a fortune and, like others, the HVAC system is like an airplane taking off. I have to use headphones to watch TV or, when it’s cold, wear a jacket and hat if I want to stay warm. Furnace Model: Nordyne M1MC 077A AW s# MIG100303958
The factory cut holes (squares) above the bedroom doors and put a small grill, as “transfer ducts.” There is an ~2″ gap under the doors, I guess to allow for airflow. The ducting “pops” after the heater stops because the metal is contracting.
Question:
Can I replace the square metal ducting with CPVC ducting?
Install CPVC ceiling return ducts in the limited ceiling space?
In the summer, the ambient temp reaches 84F, and I have to either turn the AC on early in the morning, or let it run all day to bring the temp down.
I only have floor vents (other rooms) and toe vents (bathroom & kitchen – toe vents)
A company came out and suggested I put in a heat pump and a split system in one large room. Cost: 20K!
Thank you for your time.
Michael,
Sorry for your problems. Not unfixable though but still gonna cost something. Can’t imagine a split system costing 20K. A really good mini split added to the main large room should be about a quarter of that 20K. They are extremely quiet and very efficient. Some folks don’t like the looks of the indoor unit on the wall but I think it’s a small sacrifice. My customers can’t even tell when they are running (inside unit or outside unit). You can use the noisy electric system for a backup or auxiliary system. Do a search for mini split or ductless heat pump. If you live in a cold climate make sure you buy accordingly as some work down into the sub zero weather and some don’t.
Chad
Really good insights, Chad. I think I’m seeing the solution more clearly now. The flue appears to be concentric, like you said. Soundproofing the door and furnace cavity are right on. I have a handyman friend who can help me make this happen. So glad I found your website. Thanks for being on the internet. Your help is invaluable.
Thanks Lew
With everything that I have researched on HV AC units I have finally read something that I thought about as far as moving the filtration system somewhere other than right inside the unit itself, I have the problem that you talked about with the unbelievable noise that my unit makes to the point of putting a door in the hallway and it cuts down the noise to the living room, but what about the bedrooms. It runs for 8 minutes and shuts down for 8minutes, and my mobile home is humid as I talk to people about a whole house fan and they look at me like I’m from another planet
You should send me a couple of pictures. I believe this comment section has that by clicking on img. Mobile homes are often too noisy with the supply air to each room. Very little can be done. Perhaps having a technician check to see if the fan speed can be lowered. Your unit could be oversized which would cause it to cycle too often and not remove the humidity. High humidity areas need run time to remove humidity. Bigger is not better for ac units.
Chad, I’m in an old mobile home (80’s?) and my Coleman Presidential III unit is way too loud. I have natural gas heat for the furnace in the hall and a big electric motor fan blower – on the shaft – mounted above it. I have a Ruud compressor manufactured in 2013 outside. The sheet metal blower cover door has two divided 16X20X1 filters by the blower chamber, upper and lower, and a few return vent slots (8″X15″) on the furnace door just above the floor.
From your comments above, I’m wondering if I could make a plywood door replacement for the metal blower door and equip it with one large, effective filter? Would that help the noise factor? Your thoughts, suggestions?
Hi Lew,
The fossil burning furnaces are a little harder but still you should be able to reduce some noise. It sounds like you understand my approach here. Try to move the filter as far away from the blower as possible and not right in front of the blower like is presently is. And keep the size up there around 20X25. Look for some sound deadening material that you could line some areas inside your new door and furnace cavity. I even had one customer that lined the inside of his furnace. And, As long as your flue is concentric, which I’m sure it is, meaning it’s a pipe inside a pipe. The inner pipe is the exhaust and the outer is fresh air from outside. You should be safe.