# Anyone heard of the lennox pulse furnace?



## BigBadJohn86

A guy at work has one and swears by it. I looked online and they use similar to an automotive spark plug to combust propane or natural gas in a chamber so they dont have an open flame like a traditional furnace. From what I see they come with mufflers to quiet the noise they make. They are rated at 96% efficiency but for some reason they dont make them anymore. WAY ahead of their time in the early 80s when they first came out.

My furnace I have which Im trying to keep from running when I can has no manufacturers name, no model number, BTU rating. Nothing. Just a schematic of the wiring. It puts out at its hottest 100 degree F heat at the registers, and at one point a few years ago a couple times when it kicked on drew such a load that the lights in the house got dim. What that was all about I have no idea. I dont know whats going on. If my heat exchanger is messed up, or what. I have no clue even to the efficiency rating of it. In the middle of winter with no supplemental heat it will run for 15 or 20 minutes, go off, and start back up i n less than five. Its costed me over $400 in one month before to heat my house with propane.
Is there anything I can do to see what efficiency it is or if anything is wrong with it? I wouldnt mind getting a new furnace but dont have the money right now. I hear goodmans are good and very reasonably priced too. Otherwise if I could find a used Lennox pulse for cheap in good working order, maybe I could get one of those


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## Singed Eyebrows

Yes, heard of them. Some were so noisy that owners needed to remove them. I would suggest looking for a good used condensing propane furnace instead, Randy  PS, I believe the Lennox Pulse morphed into the Aquapulse furnace.


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## blades

Only thing in the furnace that would draw an extreme load would be the blower motor. Typically the bearings  dry out or go bad from lack of maintenance. Typically a old furnace will not be much above 75% if it is very old less than 60%. You say the furnace kicks back on in 5 minutes which indicates that you have a lot work to do insulating and sealing up cold air leaks. The early Hi-efficiency furnaces ran into problems with the heat exchangers rusting out, most are now made with aluminum or stainless steel exchangers. Aluminum transfers heat faster.
On another note if your air fuel mix is not set correctly that can add to your fuel bill. Plugged air filter is another. Hot air ducts not insulated but running through an uninsulated space is another. 
The thermostatic sensor in your plenum could also be another factor.
You might want invest in a service call from a professional hvac service group.


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## sir james

Lennox Pulse furnace heat exchangers were modeled after the German V-2 rockets from WW2,they stopped making them back in the mid 90`s due to faults with the welds on the heat exchangers.

They had a program for a while where the heat exchanger was pressure tested and checked for leaks.

Heavy units,never looked forward to installing them,much more labor intensive and time consuming due to all the noise reduction requirements especially on a residential change out.

I think your money is better spent on a new piece of equipment.


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## Retired Guy

Had the pulse 80 for about 15 years until we got the $$$ to toss it. Took three heating seasons for the installing dealer to get it to work reliably. The noise wasn't a problem for us - something like a low 60hz hum in the background. The plus was, we knew it was working - not a given any time. Put in a condensing furnace two years ago and have to say that the difference is night and day. When SWMBO turns up the thermostat, the furnace comes on, every time! 

Lennox did have issues with the combustion chambers cracking and leaking CO. They need to definitely need be tested for leaks with each cleaning.


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## blades

A heads up to any one converting from a standing pilot furnace or hot water heater.  If your unit(s) are exhausting through conventional  brick and mortar chimney,   removing that small constant heat source will allow condensation to form in the chimney. Eventually leading to depredation of the mortar joints and that will mean some sort of remediation. For most the first signs of trouble are puddles of water on the basement floor or wet spot that comes and goes on a ceiling in the proximity of the chimney. It was and still is very common for installers to just replace either or both units with HE units with no attention given to this. A typical situation runs something like this: Mr & Mrs homeowner replace one unit with HE unit (as these units are all forced air exhaust, not a problem yet) sometime later the other is similarly done.  Now is when the problem starts as there is no longer a constant heat source flowing up the chimney to ward off condensation. The new appliances cycle off an on but in between the flue goes stone cold, because the new items are fan forced exhaust the cold chimney does not represent a draft problem. What does happen is that nice forced exhaust ( remember water is a byproduct of combustion) runs up against that cold brick and whoops the water and some other corrosive nasties condense on the cold walls of the flue. This causes a leaching action to begin on the mortar joints, eventually causing them to break down allowing infiltration of more moisture accelerating the deterioration. In some areas this could take many years in others less than a year.


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