Lennox Pulse 21

Reply

  #1  
Old 10-20-02, 09:01 AM
Kelly T's Avatar
Member
Thread Starter
Join Date: May 2002
Location: Ontario, Canada
Posts: 41
Received 0 Votes on 0 Posts
Question Lennox Pulse 21

I have a horizontally-mounted Lennox Pulse 21 in my crawlspace. The gas furnace was installed in January 1993. It's a big beast and more than adequately heats my less than 1200 sq ft home. I purchased the home early this year, but I just this past month replaced the furnace's filter. And that's about the extent of what *I* can presently do to the furnace, service-wise, due to my complete lack of knowledge about it. The filter was beyond disgusting, and I suspect that the furnace itself has been similarly neglected over the past several years.

My programmable thermostat will click on, about 30 seconds later the furnace responds, starts whining, humming and rumbling, then about a minute later, it booms and roars to life and seems to run fine. Excuse my highly technical description. This was its normal routine in late winter and early spring of this year, and this fall up until last week, and I don't think anything was unusual with this part of it.

But just this past week, it has been going through its normal start-up, whines, hums, rumbles away, then quits. Then it starts again, hums, rumbles away, then quits. Over and over. If I then turn the thermostat up a couple of degrees, that appears to 'help' it finally kick on. Not sure what's going on there. The other 'new' issue is that after it's already up and running, and heat is flowing out the registers, the furnace attempts its start-up routine again of humming and rumbling and trying to start all over, numerous times, even though the blower is already pumping out heat. Anybody know what is going on with this beast?
 
Sponsored Links
  #2  
Old 10-20-02, 09:31 AM
hvac4u's Avatar
Member
Join Date: Aug 2001
Location: NW atlanta
Posts: 3,147
Received 0 Votes on 0 Posts
pulse furnace

lennox is the only mfr to make this type of unit, for good reason. do a search for lennox pulse of the net, and you will find out why. this is not a machine for a DIY'er to work on in my opinion. many techs are befuddled by their operation. what you could check is the evap coil, which may be restricting airflow, causing unit to cut out on overtemp condition. this would cycle the burners off, fan continue to run, burners cycle back on. also be sure the wheel of the blower is clean. with your description of the filter, this could be all it is,
 
  #3  
Old 10-20-02, 06:12 PM
Kelly T's Avatar
Member
Thread Starter
Join Date: May 2002
Location: Ontario, Canada
Posts: 41
Received 0 Votes on 0 Posts
Thanks for your reply. I definitely won't be messing about with this furnace on my own. But I want to try to have some idea of what the problem *might* be before I have a tech come in to look at it. I did a lot of searching online for info about the furnace, but from what I've read, most reported problems seem to have been with the 1989 and earlier models. The first order of business this week will be to have someone come in and thoroughly clean the unit, and then I'll see how it performs after that.
 
  #4  
Old 10-21-02, 10:40 AM
Kelly T's Avatar
Member
Thread Starter
Join Date: May 2002
Location: Ontario, Canada
Posts: 41
Received 0 Votes on 0 Posts
update

Just had a tech in today to check the furnace, since it just kept cycling on and off this morning, refusing to fire up. Although it still needs cleaning (which is now scheduled for later on, since my local techs are booked solid) the problem was a clogged condensate line. The tech said that my furnace's line currently lies flat on the surface on my crawlspace the length of my home. He told me I should wrap the line and raise it off the floor of the crawlspace and ensure that it slopes downward so it can drain properly. Does this sound right? Any other ideas for preventing this from happening in the future?
 
  #5  
Old 10-21-02, 11:26 AM
Banned. Rule And/Or Policy Violation
Join Date: Nov 2001
Location: USA
Posts: 1,875
Received 0 Votes on 0 Posts
The biggest complaint about pulse systems is the noise. Lennox actually trains people to deal with it. It has a lot to do with adjusting the dampeners on the system. Ask you service person about it.

The condensate line is part of your exhaust system. If the condensate line freezes or gets clogged as in your case, the condensate builds up in the line until it reaches the exhaust. Where it will cause the system to shut down. This is almost the equivalent to stuffing a potato in your car exhaust pipe, the car won't start.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: