Question about Superior Lennox Blower Thermal Sensor - BTS

2 Answers

Very loud induced draft furnace

I have a 20 year old Lennox Pulse. It started to make an odd noise so I removed the panel over top of the induced draft motor while it was running. (I out it back on, tightly, of course) Now the motor growls at freakishly high volume. I had a repair guy in and he thinks its fine.

I just can't believe that it goes from not sounding like a lawn mower to sounding like a lawn mower and there's nothing I can do about it.

Posted by on

  • engineer09 Feb 27, 2009

    We have a new Lennox G43UF36B-70 70,000 btu input furnace (92% eff.) installed June 2008 in Columbus, Ohio area. During the heating season, the induced draft motor, when it starts up and continues to run during a heat cycle, creates a low frequency vibration. This can be heard at the furnace location (basement) and in rooms upstairs (single floor home). It is annoying, and after that motor shuts off, the furnace continues to run acceptably quiet. If the refrigerator in the kitchen also is running while the induce draft motor runs, there is a beat frequency vibration that you can hear being generated. That goes away when the induced draft motor shuts off.



    The dealer/installer has replaced the motor twice with a Lennox sent replacement, but it continues to be the same problem. The dealer cannot come up with an answer. I don't think this should be characteristic of the furnace operation.



    I have not seen this problem with another energy efficient furnace installed at another home. It is a Goodman GKS90703BX that has about the same size induced draft motor and exhaust vent piping connection as our Lennox. The furnace is very quiet even when the induced draft motor is running, and no noticeable vibration at the furnace or in other rooms.



    Before our warranty is up, I would like to know if there is a way to know if this is a faulty furnace, or just what causes the Lennox to operate this way. Should I insist that Lennox (or the dealer) show me another home installation of this same furnace to see if it is the same or similar problem?



    Thanks for any suggestions.

×

2 Answers

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 1 Answer

If it's a pulse furnace most were built with what's called a flapper valve and it is in need of replacement. If 20 years old it also needs to be checked for heat exchanger damage. This will need to be done by trained HVAC tech. There is no way to see inside exchanger on this system and needs to be done on table testing. This furnace at one time had a problem with heat exchangers and Lennox subcontracted this out to a company that did the liners wrong. Customers had no way of knowing there was a split in the heat exchanger until it was too late. And yes there was a warrning sent out to all people who owned one to have it checked. I CAN'T even remember the last time I saw a pulse furnace after that. I've been in the HVAC field for 30 years now. Hope this helped you.

Posted on Nov 27, 2012

  • Level 1:

    An expert who has achieved level 1.

    MVP:

    An expert that gotĀ 5 achievements.

    Governor:

    An expert whose answer gotĀ voted for 20 times.

    Hot-Shot:

    An expert who has answered 20 questions.

  • Contributor
  • 27 Answers

When you tighted it it very well could have done damage to the motor or you could have it off kilter 1 of the 2

Posted on Feb 06, 2009

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Loss of top end speed and loud engine noise


Well you might have loosened the exhaust or have bad compression from the pistons try some pressure tests and get the manual and read the specs Other than that it could be a minor repair

Mar 23, 2014 | Kingwin Duro Bearing Silent Series 120mm...

1 Answer

HI, my laptop is three years old, getting some noise from the fan, My question is can the fan be lubricated,


Have you tried blowing air through the cooling duct to clean out the dust that gets caught up in there?

Nov 13, 2013 | HP (158800-001) for Compaq Presario 1246,...

1 Answer

HI, my coolermaster laptop cooler, the U2 with 2 optional fans have been acting loud. only one fan has been acting up. it makes loud noises while the other one is silent. like a grating noise kind of. cant...


Sounds like the fan is going out. I would take it back to the store and swap it for a new one. Alternatively, if you decide to keep it you can try to put a drop of 3-in1 oil in the center of the fan to prolong and/or fix the noisy fan.

May 26, 2011 | Cooler Master NotePal U2 Notebook Cooler ...

1 Answer

G50 lennox furnace ignites and burners kick in but only burn for a few seconds and then shuts off . Appears there is heat sensing probe in front of burner. Ibelieve it is the heat sensing probe which...


the part your describing is a thermal coupler and you'll need to go to a heating and ac supply company. some small local hardware stores might have it but never found one at the big stores like home depot.
last resort if its cold where you are call the local gas company and get them to fix it. you'll have to pay for the repair call.

Jan 17, 2011 | Superior Lennox Blower Thermal Sensor -...

2 Answers

I have a Dell inspiron 1525...I have found that now, after a year and half the fan has become loud and noise. So noise, I wake up in the middle of the night, hearing my computer cooling b/c the fan is so...


you need to buy a new fan, your fan is about to give up the ghost. if you let the fan die while the pc is running, it might burn out the cpu.

fans are very cheap, like a few dollars, and do not always last forever.

Nov 06, 2010 | Dell (6F858) Cooling Fan

1 Answer

Water is starting to be seen on the pan under the furnace/blower in attic and air pressure is very low comming from the vents to cool. I am thinking there is a clog in the water piping and if that is the...


This usually happens when your system isn't charged right, meaning, over or under charged, or you have a problem with the return air being restricted like the filter being to dirty. Anyways, the coil on the inside of the unit is freezing up which is causing the excess water and the low air flow. First check the filter since thats the cheapest, but it's more than likely the charge of refrigerant thats the problem. Hope this helps.

Jun 05, 2010 | Superior Lennox Blower Thermal Sensor -...

1 Answer

I need a new cooling fan, how much are they?


The old addage "you get what you pay for".....It applies here. You can get 80mm to 120mm fans for under 20 bucks, but depending on how fast they have to spool up to keep the processor cool and how well their blades have been designed determines how loud they are, especially if they have been cheaply made....poor bearings and poor blade design equals noise. Bigger fans are actually a lot quieter because to move air they do not have to turn as many rpms. Get the biggest best made fan you can that will sit confortably in the case without interference. Also, download the little program called Speedfan, it will monitor fan speeds and system temps and make adjustments to the fans to keep them in the quiet range when possible.

Jan 16, 2010 | Sony CPU FAN CPU Fan

2 Answers

Lennox Fan will not come on when set to ''auto'' position.


Expensive is relative, service calls are never free. But if you have an idea what the problem is, you are armed against an unethical service company. Now to what you describe, could be a couple things, first let me explain the difference in fan speeds. Furnaces that both heat and cool have multi-speed blower motors. High speed is for cooling and lower speeds are for heating. The fan switch at the T-Stat turns on the high speed fan relay. The lower speed fan is turned on by either a temperature activated switch (silver box mounted on front on furnace above burners) or a time delay relay which is solid state. That being said, your problem could be a defective fan switch or one of your blower motor windings has gone bad. Most motors have 3 or 4 speeds and a technician could just change speeds and all would be good. A fan/limit switch is not so expensive that you would replace the unit. Bottom line, unless your really handy, a heating company is in your future. Good luck and please rate my answer if it was helpful to you.  

Dec 31, 2009 | Superior Lennox Blower Thermal Sensor -...

1 Answer

Loud buzzing noise......possibly the fan?


is the battery ok? have it tested, sounds like a weak battery that is failing, the battery lasts about 2 years in most laptops.

Sep 04, 2009 | Compaq Presario Fan

Not finding what you are looking for?
Computer System Cooling Logo

663 people viewed this question

Ask a Question

Usually answered in minutes!

Top Superior Computer System Cooling Experts

Brian Sullivan
Brian Sullivan

Level 3 Expert

27725 Answers

Justin
Justin

Level 3 Expert

2072 Answers

joecoolvette
joecoolvette

Level 3 Expert

5660 Answers

Are you a Superior Computer System Cooling Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...