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Replacement Gas Furnace

Neil030606 Member Posts: 3
Hi all hope someone can help us
We moved a year ago our house has a Lennox Pulse 21 gas fired furnace, all worked fine and we didn’t use the heating in summer
When we tried to restart in winter it only blew cold air we then called out the company who had serviced it for the previous owner
As the boiler is over 25 years old it was obvious they didn’t want to touch it and basically condemned it , we then got in touch with a local plumber to see if we could replace it , he came up with using two boilers to match the power output but struggled to work out how to join them together
Our dilemma
we would like to keep the air blown system as all the ducting etc is in place and does anyone out there know of a air blown system as powerful as the Lennox pulse that would fit to the existing ductwork easily
Thanks in advance


  • ayetchvacker
    ayetchvacker Member Posts: 63
    The Pulse is unusual but it is a good furnace. Unless it’s been neglected I would think there may only be a minor issue. It would not surprise me if a service person who is unfamiliar with a piece of equipment (which is old) condemns it without cause. There’s no way to be sure but that does happen. Did they give you a detailed invoice explaining why they condemned it?
    There are many furnaces out there comparable to yours. What you need is a good contractor who is proficient in changing out furnaces and know how to size them correctly. 
    Have you checked the “Find a Contractor” tab on this site?
    Your plumber may be experienced but my gut tells me he’s barking up the wrong tree is this case. 
    Fixer of things 
    Lead Service Technician
    ‘09Moto Guzzi V7
  • wmgeorge
    wmgeorge Member Posts: 222
    I am confused you talk about a Lennox Pulse and then boilers? Which is it?

    The Pulse had a recall years ago for bad heat exchangers they leaked. Most bad heat exchangers were checked and replaced at the time or credit given for a new furnace. Plumbers normally do not do furnaces. Find a HVAC contractor and have it checked. The Pulse had nothing special size wise, any competent heating and cooling contractor can replace. I replaced mine with a Trane 96% 2 stage gas and ECM motor.
    Old retired Commercial HVAC/R guy in Iowa. Master electrician.
  • reggi
    reggi Member Posts: 522
    @Neil030606 There may be some "terminology" barriers..Why don't you post some photos of the system and perhaps we can get a better understanding of what your saying...
    One way to get familiar something you know nothing about is to ask a really smart person a really stupid question
  • Neil030606
    Neil030606 Member Posts: 3
    Hi all thank you for your replies , as far as I know the furnace has been serviced annually before we moved in and it had a part replaced (picture included) it worked fine for a few months and as summer came we stopped using it as winter approached we discovered it only blew cold air. We got in touch with the company who the previous owners used, it was obvious they wanted to condemn it they couldn’t quite diagnose the fault
    We decided to wait and think about what to do, as time went by we decided to see if we could then get it replaced and the plumber who called could only source one half the power of the Pulse and has had trouble finding a way to connect to the ducting.
    So here I am asking for advice

  • wmgeorge
    wmgeorge Member Posts: 222
    edited March 2022
    Did he pull the front cover off and check the flapper? You need to find a competent HVAC repairman. This guy sounds like a nobody. Post the Btus on the nameplate and the Model number, guys here who are closer to you can make a brand suggestion.

    Other than the flapper assy not much else goes wrong. I owned a Pulse for years.
    Old retired Commercial HVAC/R guy in Iowa. Master electrician.
  • Neil030606
    Neil030606 Member Posts: 3
    Thank you again I think some of the terminology problems are due to the fact I’m in the UK not the USA not many people use furnaces in Britain the previous owner was a businessman who traveled to America in the 50s he liked the idea of blown air he also brought home the idea of self service and set his shops up that way which was quite a revolutionary idea at the time
    I thank you for your responses and continue to search for solutions here in Britain