Lennox Pulse furnace not turning on?
#1
04-18-11, 07:07 PM
Lennox Pulse furnace not turning on?
Hi All,
I have a Lennox Pulse furnace which is over 20 yrs old (just bought the house last year). It worked fine all winter but the other day I noticed the thermostat light was on (calling for heat) and the furnace wasn't running.
I went downstairs and took the cover off the furnace to see what I could see, and didn't really see much. Just a green LED which was not lit up. There was a "light switch" on the outside that I flicked back-and-forth a couple times, thought maybe I bumped it working in the basement. Just heard some clicking (like a relay) and then put it back in the position it was originally in. About 15 minutes later the furnace did kick in.
Tonight, the same thing happened. I turned the furnace up when I got home and the red light has been on the thermostat for about an hour. Nothing happening with the furnace. I can turn the fan to manual and it starts, so guess the wiring is OK.
Do any of these symptoms suggest anything typical of the Pulse? We have a home warranty so going to call them tomorrow if it's still not working.
Thanks
I have a Lennox Pulse furnace which is over 20 yrs old (just bought the house last year). It worked fine all winter but the other day I noticed the thermostat light was on (calling for heat) and the furnace wasn't running.
I went downstairs and took the cover off the furnace to see what I could see, and didn't really see much. Just a green LED which was not lit up. There was a "light switch" on the outside that I flicked back-and-forth a couple times, thought maybe I bumped it working in the basement. Just heard some clicking (like a relay) and then put it back in the position it was originally in. About 15 minutes later the furnace did kick in.
Tonight, the same thing happened. I turned the furnace up when I got home and the red light has been on the thermostat for about an hour. Nothing happening with the furnace. I can turn the fan to manual and it starts, so guess the wiring is OK.
Do any of these symptoms suggest anything typical of the Pulse? We have a home warranty so going to call them tomorrow if it's still not working.
Thanks
#2
04-19-11, 04:35 PM
Member
Lennox Pulse furnaces are very hard to work on for a homeowner let alone hvac techs. Some parts are no longer available. Most companies don't know how to work on them and wont work on them. They are very unique.... no other furnace out there works the way they do. You will need a Lennox tech who knows pulse furnaces to get it working properly. Most likely you have a dirty air flapper.... The Heat exchanger needs pressure tested yearly and there is a high probability that the heat exchanger has failed. Most companies that dont deal in lennox or never worked on these units will not have a pressure test kit to do this test.
#3
04-21-11, 04:20 AM
Thanks for the info. Very insightful. I had a Pulse in my last house and the heat exchanger went to hell. Luckily the home warranty covered it and only cost me $85 to replace the furnace. Was hoping the same thing was happening here, but the service tech found the drain hose was plugged. It's been working since.
Had it serviced before the winter last year and the tech checked the pressure and said the pressure would slowly drop when he was testing it but was within spec. It's under a home warranty as well and thought we might wait it out and see if the goes before the warranty expires. Got a couple months yet but pretty much the end of the heating season now, so not sure what we'll do at this point.
Had it serviced before the winter last year and the tech checked the pressure and said the pressure would slowly drop when he was testing it but was within spec. It's under a home warranty as well and thought we might wait it out and see if the goes before the warranty expires. Got a couple months yet but pretty much the end of the heating season now, so not sure what we'll do at this point.
#4
04-28-11, 01:57 PM
Pulse furnaces have a PVC drip leg that can get filled with junk over a period of time. If that gets clogged your furnace will not run. If it's been cleaned out already there should be a rubber cap over the bottom of it, if not that means it's never been cleaned and that may be something to check out.
