# Furnace makes ratcheting noise



## 1972vet

Need a little help with this. I have a trane furnace, now about 4 years old. This annoying ratcheting sound only occurs in the winter and I believe it is caused by the humidifier but I cannot determine how or why...and most importantly, how to make it go away.

When the cold weather approaches, I take out the humidifier pad and clean out all the dried up hard water dust etc. and turn on the tap to start the water flow. It has a humidistat and I set it at about 40. Theory is, when the humidity in the house drops below that then the humidifier calls on the water tap to soak the pad...and when the furnace comes on, it blows out some nice warm humid air. After a varying period of time, when the furnace comes on (only when it first starts up after it's called upon to do so), I then hear on occasion, this annoying ratcheting sound. I can certainly make it go away by turning off the humidifier but that defeats the purpose.

Is there some expert here who can help diagnose this issue? I have had several different hvac folks here to look things over and each one wants to charge me some sort of fee for a hit and miss diagnosing session. These folks have replaced parts relating to the gizmo that clicks in gear when the furnace wants to start...changed out the heating element (electric furnace), and checked and replace some wires...all of which I strongly believe was not necessary. As stated, the furnace is now only about 4 years old but this issue began the first winter after it was installed (installed it in the summer).

I love the slightly humid air as it does make it feel warmer in the house and does so while it uses less energy (when it's slightly humid, the furnace doesn't come on as often, thereby saving electricity costs).

Any one of you experts here have a clue what I can do besides just leaving the humidifier turned off? :4-dontkno


----------



## SABL

Hi vet!!

The noise is coming from the humidifier itself?? Or are you hearing the surrounding ductwork as it expands and contracts??


----------



## 1972vet

Hi ya SABL,

Thanks for the reply...no, the noise comes from inside the furnace itself. I actually think it is the relay that makes contact when the heating unit kicks in. When it works properly, the relay clicks once and the blower comes on. Warm air comes out as a result as it should. The noise (ratcheting sound) I believe is that relay that makes continuous rapid contacts for some danged reason, only during the Winter and ONLY when I have the humidifier turned on.

The first hvac guy I had out here also believed it was that relay so he took out the one that was in there and put in a new one. The old one at that time was only a year old lol...so now, I have a 4 year old furnace with a 3 year old relay that still makes noise. I called the guy back after he stole my money for replacing the old (new) part and told him it still made the same noise so he wanted to take more money to try something else. I thought about a turnip truck for a few seconds, then hung up the phone on the guy in the middle of his schpeel.

To give you a better idea of how this sounds, imagine what a morse code (telegraph) key sounds like when it is used to click out the morse codes. Now imagine that key being clicked very very rapidly for a few seconds. That's exactly what it sounds like and it comes from inside the furnace. The furnace unit is also what makes the air conditioner do it's job. However, in the summer the noise never occurs, and in the winter it doesn't either until I turn on the humidifier. I've isolated the events under which this annoyance can occur and last winter I didn't hear it one time but that's because I chose not to use the humidifier.

It's getting real cold here in the midwest now and I'd like to use it but the danged noise is annoying.


----------



## SABL

Hey vet

I am showing a 5 year warranty on almost all Trane products with the exception of the humidifier pad.

http://www.trane.com/Residential/TraneOwners/Warranties/Product_Warranties_2005.pdf

It does sound like the relay may have dirty contacts ( not the type found in little black books). I can't see any reason for the relay to fail so soon unless the humidifier is defective and pulling more amps than the relay can handle. It's a shame I am no longer in the field where I could ask one of the HVAC techs for an idea or solution. I'll ask my son and see if he has any contacts. I know of one guy but haven't seen him for 22 yrs .... he was a certified Trane tech. 

See what your warranty covers and if you can't get help that way, I will get into this a little deeper.

Good luck and keep us posted.


----------



## 1972vet

Ahh, well...since the relay was already traded out, it voids any warranty coverage for it. The original equipment relay is already gone. At least that's their story (typical warranty response in my book). 

The amp issue from the humidifier was also suggested early on. That's also one of the things the guy did the first time he was out here. There was more current being called for than was evidently necessary so he lowered something or other (he said). Also, at that time, he found that my unit was set up for 10,000 btu (don't hold me to it, but I think that was right)...so he reduced that as well. Now I believe it is set to 5000. Sound right? I know it was something like that. Either it was 10 and reduced to 5 or 15 reduced to 10...something along those lines.

Anyway, back to the relay issue. Since the first one was replaced and the other brand new one still made the same noise ('bout a half hour after the guy left dangit), wouldn't that mean if I keep replacing relay switches, the same result can be expected? That's my train (trane) of thought anyway...pardon the pun. I just have a problem expecting different results from the same experiment. If the sun ever comes up in the west, one day I might give it another spin :grin:


----------



## SABL

I'm thinking that any replacement by a certified Trane tech would only extend the warranty and not negate it. If you requested warranty service from Trane they should still stand by their warranty policy and effect the correct measures to protect you as a consumer.


----------



## Tumbleweed36

Hi,

I don't have Trane but a Lennox that was two years old when I moved in to this house which was also two years old. It did exactly the same thing. I had a furnace man look at it and he said it was just the way they were and they couldn't do anything about it. He was from the company that installed it. 

I was not satisified with it, so had another guy come out (bills going up) and he thought it was a simple vibration and strategically placed some duct tape between some parts in there to stop it and it worked for about a week with no noise, and then back to the way it was. We endured the winter that way.

Well, the summer passed and coming into winter, I wanted to have it serviced previous to the winter. I actually called another furnace man to clean and service it (an older man) and he said he knew what it was. He grabbed the furnace exhaust pipe and jerked it around until he moved it (it was in there tight) quite a bit and lo and behold, it has not made a peep since he left and we have been using it for two months now. He said the vibration works up from the bottom and takes place in the metal furnace pipe and many are like that. He said it won't do that again and if by chance it does, give him a call and he will give me a free three minute treatment to fix it.

I have no idea if that is a possibility with yours, but thought I would mention it since it took the third furnace man (one who had a lot of experience) to find and correct the issue. Mine sounds exactly like yours in what was happening. It is running now and one can barely hear it running, the vibration is gone.


----------



## 1972vet

Thanks for posting Tumbleweed36. Did yours have a humidifier? I understand some of the peculiarities regarding vibration noises, duct work noises etc...however, my issue relates only to the winter and only when I decide to turn on the humidifier. The furnace works just fine. The humidifier also does the chore but after a short while, and especially the colder it gets, the more often it wants to make the chattering noise. If I never turn on the humidifier then I would never hear the noise.

@SABL, sorry if I confused you but the relay was replaced by a service tech that I called when this all first began. I since contacted trane about the warranty and because I had the part replaced by some heating and cooling place, not trane, they can't honor it. I have my doubts that it would have made a difference really. If Trane wants to, they can certainly come out here and do the same thing. That's where I start wondering...what would be the point. The original part was a trane relay. It was replaced by a local service tech. So, If Trane wants to replace it again, even if they charge me for it, I would bet the farm, it would still make noise. No?


----------



## SABL

I'm going to say Tumbleweed36 has made a good point. Unless you actually pinpoint the noise to the relay itself (contact chatter) I would look at the surrounding ductwork or venting (flue). The location of the furnace will be a factor and if it is located in a remote area that is not heated you will get greater expansion of the surrounding metalwork in the winter months and a constant ticking noise until the components settle out and quit moving.

If the problem is isolated to the relay you may want to get Trane to do a repair but ask them if the repair will revalidate your warranty :grin:


----------



## 1972vet

Thanks SABL. I think you're on the mark with calling trane out here even if it costs me. Over the past 4 years I would guess I've had about 4 service techs here to look at it. None were Trane employees but the guy who replaced the relay is the one who said that's where the noise was coming from. I have to agree. I just disagree with continuing with HIM since his diagnosis did nothing to remove the noise.

It is definitely not duct work. The furnace is located inside the house in, what I call, a breeze way. It is nonetheless, heated and cooled. The small room where it is located is also a utility room where the washer and dryer are located. I can stand right next to the furnace, as I did when the tech was here, and listen for the sound. It is precisely what I described above. When the thermostat calls for heat, the relay kicks in and clicks. When there is no humidifier turned on, then all is well. The furnace blower and heating element kicks in gear and does it's job.

Even when the humidifier is on, everything works just fine too...except intermittently I would hear the noise which is the same sound the relay makes. When that relay keeps clicking away rapidly, it sounds just like a telegraph key (in a rapid fire mode so-to-speak).

I guess I'll have to surrender to it and call in the Trane folks.


----------



## SABL

Sounds like the relay does not have the capacity to handle the load or the humidifier needs checked for excessive current draw. It could even be a weak neutral connection in the circuit that activates the relay, which may also cause the chattering effect. Now that I think about it, the circuit that controls the relay needs to be traced and checked for a problem and it may not be the relay itself. The authorised Trane rep will be your best bet and may get you the balance of the warranty back. 

Good luck


----------



## Stedman

I've dealt with this issue on a commercial application. The package unit was on a roof well out of earshot for anyone except the guys in my company who would be servicing it so it went several years without being addressed. Long story short the building caught fire (it was cooking equipment, completely unrelated to the unit itself) and we had to run the thermostat/humidistat wires again during the remodel process. I never noticed it until i saw this thread last night and went to that customer to check it out today and noticed that the clicking sound was gone. 
My best educated guess is that the chatter is being caused by feedback or voltage loss in the thermostat circuit. It may not even be a relay involved with the humidifier, it could just be that when the humidifier engages it causes disruption in the voltage that engages the chattering relay. 
If you're ready to give up trying to fix it yourself and call a tech getting a Trane certified tech really isn't going to give you much of an advantage since your warranty is so close to running out anyway. I'm not Trane certified but i am certified with several other manufacturers and from experience nothing that a certified rep can do will re-instate warranty. I could go into a rant about why companies require "certified" techs to honor or terminate warranties but that isn't what this thread is about. 
My best advice in finding the right technician is to contact (preferably in person) a local HVAC parts supplier that isn't a Trane distributor and ask the guys behind the counter who they would get to work on a Trane furnace *with the humidifier*, and make sure they understand that other techs have failed to rectify the problem. You may even be able to describe your problem to them and get a quick answer you can fix yourself. Whenever they make their tech suggestion (even if they're not necessarily a Trane tech)make sure to ask for an individuals name rather than a company name then when you call them make sure to request that particular tech to come out. Next it is absolutely helpful to the tech if you're not standing over them as they try to diagnose and fix your problem. A lot of working on these problems is trial and error and they're less likely to try something that may produce a negative result if you're in the same room with them. Personally I've actually fired myself from jobs and given customers the phone number of competitors because they insisted on watching the entire time or even worse, trying to talk to me while i was working. Give them their space, be polite, have confidence that they do in fact know what they're doing, and be confident that your problem is going to be fixed. If after they leave you find out that its not fixed don't get discouraged, call that particular tech to come back. Its better to use the same guy over and over because he'll be able to remember what he already tried and wont be starting fresh, developing a personal history with equipment is what the majority of "experience" is in this field. 
If you don't know who the parts suppliers in your area are you can try going to hxxp://johnstonesupply.com and entering your zip code. If you don't have a Johnstone nearby to visit then try searching google. Getting a word of mouth recommendation from someone is worth more than any advertisement you may see in the yellow pages.
Good luck


----------



## SABL

:4-clap::4-clap:

Good advice Stedman...thanks.


----------



## speedster123

If the pad wheel starts to touch or grab the tin return plenum, for what ever reason, the voltage will increase trying to turn the pad.
The power bypass humidifiers arent really a wallet killer. How come no one suggested to give up the ghost on this one and replace it?
Seems as if you are paying for numerous service calls anyway.
2 hours tops on replacing the unit and most likely closer to an 1 hour labor.
Get a good quality humidifer from a supplier.


----------



## 1972vet

Excellent response...Thanks Stedman! I'm going to take your advice. Thanks to all for your input.

@speedster123:


> If the pad wheel starts to touch or grab the tin return plenum, for what ever reason, the voltage will increase trying to turn the pad.
> _I haven't the slightest clue what that means_
> 
> The power bypass humidifiers arent really a wallet killer. How come no one suggested to give up the ghost on this one and replace it?
> Seems as if you are paying for numerous service calls anyway.
> 2 hours tops on replacing the unit and most likely closer to an 1 hour labor.
> Get a good quality humidifer from a supplier.
> _I have a Honeywell. Is that not a good quality?_


----------

