Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Loud Lennox Pulse - need info

kpcarlson Member Posts: 7
I have been reading the Wall for several years now but this is my first post. The neighbor lady behind us has a Lennox Pulse hot air furnace. The sound it broadcasts into our yard is a LOUD, low pitched pulse which permeates everything including throughout our house. It does not matter if we have the tv/radio on I can always tell the instant that thing starts up. I have talked to her about it (that's when I found out it was a Pulse) and have also determined that the sound is coming from the intake pipe. It bounces off a concrete wall and towards us. We are often woke in the middle of the night by this thing. Besides that the sound is extremely annoying, you just can't escape it. She called the local heating guys and they told her there's nothing that can be done - it's a Lennox Pulse. I think they just don't want to deal with it. Anyhow, I've done some reading up on this contraption and now know some of the history: cracked heat exchangers, CO poisonings, recalls, etc. I also understand there are some specific periodic maintenance actions that need to be done to the Pulse every four or five years. The lady tells me she's been at that house since 1995. I don't think her Pulse has ever received any of the required servicing in that time. Things I've noticed about it besides being very loud are that it "misses" while it's running. Also have noticed what I think are long cycle times, I have timed it running over 40 minutes at times and we have reasonably mild weather here. I don't know if there is anything that can help stop the very annoying, disturbing noise this thing makes, but once again nobody around here wants to touch the thing. She says I can try to block the sound somehow, so I plan on building a concrete block wall around the intake pipe - giving plenty of clearance of course - just something to reflect that noise somewhere else. I will also suggest she get a CO detector or two. My question for any Pulse experts out there is how bad is it to let the periodic maintenance slide on this unit? I'm about to go over to start on the concrete sound wall so maybe I can have some interesting info about the Pulse to give her. I can always hope it breaks down completely some day. Thanks for any information and advice. Kurt Carlson in Astoria, Oregon.


  • Empire_2
    Empire_2 Member Posts: 2,343
    Lennox Pulse

    I believe the recall for defective were for pre 1994 models.  Does not mean there is not another issue(s).  All heating equipment should be serviced every year for proper operation and safety concerns.  The Pulse used an insulation block on the intake which was supposed to deaden the sound it makes.  FLAPPER MEMBRAINS NEED TO BE CHECKED AND REPLACED IF WORN.  Sorry about the caps.  Gas pressure is set at 2.0"w.c and is pretty sensitive.  Before you built the great wall of Pulsdome, consider elbowing the intake and exhaust upwards.  There are strict guidelines as to how long the total runs are and elbows used.  You are not crazy,...They can be annoying.


    Mike T.
  • kpcarlson
    kpcarlson Member Posts: 7
    Loud Lennox Pulse - need info

    Mike T, thanks for the info. I'll pass on the importance of maintaining the flapper valve. She's been at the house since 1995, but the furnace may be a lot older than that. I might take a look at it to see if I can find out the year. Thanks for the tip on the elbows, but I don't think it would do much good (if you heard it and saw the location you would see why) Anyhow if it were mine I would be fixing it, but since it's not mine I'm not going to touch it. She can't seem to get the guys around here to do anything about it. I'll be measuring it up tomorrow for the concrete blocks sound enclosure, and I'll pass on what I have learned about the maintenance to her.

    Kurt C.
This discussion has been closed.