Need Help Understanding Heat Cycling - HVAC - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC


Thread Tools Display Modes
Old 02-07-2013, 11:03 AM   #1
Join Date: Feb 2013
Posts: 4
Rewards Points: 10

Need Help Understanding Heat Cycling

We recently had a problem where our heater would just stop working and I would have to tap the panel door to the unit in the attic, and it would kick back on. I replaced the pressure switch after seeing the code flash on the unit, but that didn't fix it. I then saw the code for "High Aux or Spill Limit Switch Open" so I called a repair guy out and he never could find any problem. He tested and the wiring and cleaned all the connectors and it's been working for 4 days straight without a glitch. All of this has caused me to pay closer to attention to the unit and I've noticed that it cycles on/off quite a bit. I timed it and the flame kicks on for about 3 1/2 minutes and the blower starts about 15 seconds after it ignites and it stays on for about 6 minutes. Then everything stays off for about 5-6 minutes and repeats. It's set for an internal temp of 68 and it's been about 35-40 degrees at night lately.

I have the original thermostat (12 years old) and I've read about being able to adjust the anticipator but don't see anything like that on my thermostat. I found a decent thermostat at the hardware store that says you can adjust the swing to help reduce the amount of cycles. My question is should I just buy the new thermostat and increase the swing or should I have another repair come out and look for more problems.

Thank you.


jason92s is offline   Reply With Quote
Old 02-07-2013, 12:12 PM   #2
Hvac Pro
yuri's Avatar
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 15,977
Rewards Points: 92

It could be the tstat but the only way to know is to put a volt meter between W and C on the board when it is running and see if the tstat shuts off. Most units have the burner run for 90 seconds B4 starting the fan so you may want to check that again or have a different problem. I would buy a Honeywell Focus Pro tstat from HDepot and replace yours if it is that old. Average life of a tstat nowadays is about 10 yrs.


"Cut it twice and it is still too short".
yuri is offline   Reply With Quote

Thread Tools
Display Modes

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

Similar Threads
Thread Thread Starter Forum Replies Last Post
VisionPRO Setup Functions & Heat Pump infoskr HVAC 43 07-12-2015 04:28 PM
Heat pump is not running on Heat mode frank06 HVAC 17 03-13-2012 03:34 AM
Using Gas heat during Defrost mgroves HVAC 15 12-18-2010 05:51 PM
Comparison and Heat Pump Selection help... ChrisDIY HVAC 7 03-06-2010 08:34 PM
Heat Pump Woes Zenica HVAC 50 01-27-2009 07:37 AM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1