I've noticed the last week or two that in the morning when we wake up and when the heater is on, the air it's blowing out is cold. Sometimes between 70-75 degrees according to my Infared thermometer. After a few hours it'll start blowing out hot air, 115-120 degrees. I had a tech come out last Friday afternoon, and of course it was blowing out hot air when he arrived, with a steady flame from the furnace in the attic. House is only about 10 years old. I am going to see if they can send someone out again first thing in the morning one of these days, but can someone guess why it's taking several hours to start blowing hot air out? Filters are changed on a regular basis, and the tech last night said the unit looked clean, insulation and duct work were all good. Heat is scheduled to come on at 6:30am, but it's usually several hours later until the hot air starts working and the house gets up to the desired temp of 71 around 10am.

Set the heat to come on at 3am. Not even going to charge you for this one.

Maybe a faulty igniter? Fires sometimes and not others

This is weird? The heat should come on based on a call for heat which could occur at anytime- middle of the night etc. It sounds like your blower is in auto so it runs continuously and you’ve farkled the settings on your fancy thermostat.

It sounds to me like the fan is not in auto and is running constantly. If it was changed to auto it would shut off and on soon after the burner ignited. I don't know if that is the case but it sounds like it.

mine wont ignite at all... service call last week, part ordered only $600 for the new gas valve he will be installing tomorrow..

I meant manual, I misspoke- you are correct on the blower.

Check T-stat fan mode. Sounds like it may be in auto-recirculate vs. auto. If so, change to auto and see if that fixes problem.

No failure to ignite after the set retries will cause the gas valve circuit to disable. It will take a power cycle to reset. Same with the vent limit switch and some of the other roll-out switches. They are manual reset.


OP check your thermostat and see if you have a setting in there for the system to warm up or cool down at a specific time, check if you have a ventilation period built into the schedule, etc. If you DM me the model of the t-stat I can tell you how to get into the config and what settings to check. I can also give you some steps to troubleshoot it your self when it is happening.

The fan is set on a timer to allow the heat exchanger to come up, validate flame, and heat up before turning the fan on to prevent a blast of cold air.

I did verify fan is in Auto mode, and not On. I thought the same thing too this morning, but verified it was set on Auto. The temperature in the house was about 70, thermostat set to 71 and when it was blowing the cooler air it got down to 69. Finally, the hot air started coming out and quickly got back to 71.

Your flame sensor is probably dirty is my bet. Pull the panel off and take a dollar bill and clean it. Seriously.

DM him. He smells like cheap peat moss whiskey but otherwise, good dude and knows HVAC. He will get squared away.

I can still taste that nasty stuff.

Both of y'all wouldn't know a good scotch if a buddy handed it to you, and it shows.