Furnace not getting hot enough - Blows cold air

Questions about repairs and parts for Coleman furnaces, air conditioners and heat pumps for manufactured homes. Click here for Coleman parts.

Moderators: ponch37300, Mark, flcruising, Greg

Furnace not getting hot enough - Blows cold air

Postby Gynotai » Sun Dec 21, 2008 4:08 am

Hi.

I have a Vexar (Coleman) DGAA070BDTA Furnace that's set up for Natural Gas.

Last year I replaced the Gas Valve because the Diaphragm had a pinhole in it, and it worked fine last season. Now it seems like I have another issue.

I understand what the furnace does prior to it starting, and everything works fine. It ignites fine, the blower starts, and everything starts the way it's supposed to.

The problem I'm having is it seems like it's not getting the air hot enough. I have air coming out of all the vents in my house when it turns on, but the air comes out cold.

I'm under the impression that the air passes by the "box" that houses the flame, heating the air on it's way into the ducting. Is my assumption correct? :)

At the furnace, there is a metal panel that's positioned just below the "box" that contains the flame. I removed this panel then started the furnace. I'm under the assumption the air at this point should be reasonably hot in order for it to arrive at the various ducts in my house warm.

It's barely even warm at this point.

It's my opinion this is where the problem is. I can't expect anything resembling warm coming out of the registers if where the air get's heated is not that warm.

What can cause this? A partial clog in the gas line? The valve appears to only gave two positions; open and closed, and the only way I can see to get things hotter is to increase the amount of natural gas that goes into the furnace.

Am I full of hot air? :)

Thanks in advance!

Gynotai
Gynotai
 

RE: Furnace not getting hot enough - Blows cold air

Postby Robert » Fri Dec 26, 2008 11:05 pm

Hi,

Check burner and burner orifice to ensure they are clear with no blockages.

Make sure roofjack is not clogged or damaged.

If all ok, call an hvac tech to check manifold gas pressure and inspect furnace heat chamber.



Thanks,
Robert
Some people are Humbly Grateful, while some are Grumbly Hateful.................... Which one are you ?
User avatar
Robert
Moderator
 
Posts: 6413
Joined: Wed Feb 28, 2007 12:07 am
Location: Tennessee

RE: Furnace not getting hot enough - Blows cold air

Postby Gynotai » Sat Dec 27, 2008 2:48 am

Hi.

Thanks for replying, but I'm happy to say I followed my suspicion and I was right. I took the Gas Valve off and found that a Spider was camped out in the nozzle. I cleaned it all out, put it back together, and it works perfectly.

Thanks again for replying!

Gynotai
Gynotai
 

RE: Furnace not getting hot enough - Blows cold air

Postby Robert » Tue Dec 30, 2008 10:35 pm

Hi,

You're very welcome, happy to help. Yep, spiders and/or spider webs are the burner orifice blockages I was eluding to in my previous reply.

They love to get in there and take up house.


Take care and best wishes,
Robert
Some people are Humbly Grateful, while some are Grumbly Hateful.................... Which one are you ?
User avatar
Robert
Moderator
 
Posts: 6413
Joined: Wed Feb 28, 2007 12:07 am
Location: Tennessee


Return to Coleman Service & Repair

Who is online

Users browsing this forum: Bing [Bot] and 2 guests