Gas and Oil Home Heating Furnaces - uneven heating - cool rooms

I'm in a newer single story house with a 2 unit air/heat system, all vents are in the ceiling, fed from flex duct. The heat unit is in the attic. During recent colder days, I've noticed a substantial temperature difference in 2 rooms of the house. The master bed & master bath are always much colder than any other room. I've even closed off vents in rarely used rooms hoping to provide more heating to the rest of the house. I'm not familiar with heating systems at all....which is why I'm here. I have looked for simple things like leaks in the duct work to these rooms & found nothing. I have, however, noticed that the duct feeding the master bath is smaller (6") than other rooms. So....a little help? Would replacing the flex with larger diameter flex increase heating to these problem rooms? Are there other things I should be looking for?

Thanks,
-Bill

Hi Bill,

Not knowing where you are at, but I take it your not in MInnesota where it's -20 out tonight.. :-)

Anyway, You could incresse the duct size to 8" to allow more air flow into the rooms.. But check the room for any leakage around the windows, doors, outlets, and ect...

Do you have any return vents in that room? (take it you don't if everything in the attic) Also if you have one return, maybe the doors are close for those rooms, and it not allowing the air to get out of the room. If you have no returns in the room, you want to make sure the door is cut on the botto side to let the air escape the room.

You dont say just what you have for heat here.First is the filter clean. Is the blower on high speed ?
like jay said is the door off the rug ? Take and open the door to this room about 1/2" to a 1" with the blower on did it go shut ? If so cut some off the bottom of the door.

Now can I put a bigger pipe on it????? What are how is the duct lay out in the attic. "Newer home" how new?Call the guy that put it in.

If that 6" run goes to the main trunk line you might be able to make it bigger. But have you looked at the flex pipe up there lots of times they like kink over when they make a bend and stop the air off some . Look around first here.;) ED

2 unit system? What rooms are on what units? This could be as simple as turning up a thermostat. There might also be some design factors or insulation factors that make the bedroom harder to warm than the rest of the house. Is the bedroom/bathroom on a wing by itself so it has more outside walls than other rooms? More windows? If the house is still under builder warranty, have them do an "air-flow analysis" and check the insulation over the cool areas. Insufficient attic insulation will often show up in heating season more than in cooling season. Don't be afraid to keep calling the builder back until the problem is resolved. They sometimes do a poor job the first time in hopes that you'll give up and go away and they'll get off cheaply.

Good luck.

Doug M.

Originally posted by Ed Imeduc
You dont say just what you have for heat here.First is the filter clean. Is the blower on high speed ?
like jay said is the door off the rug ? Take and open the door to this room about 1/2" to a 1" with the blower on did it go shut ? If so cut some off the bottom of the door.

Now can I put a bigger pipe on it????? What are how is the duct lay out in the attic. "Newer home" how new?Call the guy that put it in.

If that 6" run goes to the main trunk line you might be able to make it bigger. But have you looked at the flex pipe up there lots of times they like kink over when they make a bend and stop the air off some . Look around first here.;) ED
I agree with the other comment...
Return air vent do help.. Im a sheetmetal mechanic for 30 years.. and the worst mistake is installing flex duct.. It should only be use in short distants.. under 3-4 foot.. Flex duct adds too much static pressure to the system .... if you can install solid round.. and insulate it would be the best way. and the least amount of bends and changes the bettter