Lennox P21 - http://www.hvacmechanic.com/ Forums

Original message

jamiechipper

40.0.40.10

"Lennox P21" , posted Fri 3 Oct 09:16

I just moved into a home and thought my furnace was working... was I wrong. The furnace is a Lennox P21. It was purchased in 92... I can tell by the serial number.

Problem: The furnace only starts when it wants to. For example, if I turn the power off and back on, it works sometimes. Most of the time it does not. When it works, it only works for like 15 minutes and shuts off. When it shuts off a green blinking light occurs for 2.5 seconds on the igniter control.

What I have done thus:
1. Intiated furnace by thermostat
2. Restarted furnace with switch for greater then 10 secs
3. Restarted furnace for over 1 hour
4. Replaced diaphragm and gasket
5. Cleaned flame sensor connections

The guy at the only lennox shop near us is extremely busy and does not have time to come out to my place today. He recommended replacing the igniter control, but not sure that is the problem if I am getting a blinking light (and it is expensive). What are you thoughts?

It is cold up here in the upper peninsula of MI! Wife and kids are not happy. Please help!

Replies:

yuri

142.161.103.13

"Re(1):Lennox P21" , posted Fri 3 Oct 20:13

That is a Lennox Pulse unit and only experienced Lennox techs can service it due to its complexity/quirkiness. I would buy a few small space heaters for now and get the experienced guy out to service it. Otherwise you are just guessing/throwing $$ at it.

Yuri