Zone Damper Sticking - HVAC - DIY Chatroom Home Improvement Forum


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

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Display Modes
Old 02-28-2010, 02:51 PM   #1
Member
 
Join Date: Oct 2009
Location: NC
Posts: 31
Rewards Points: 25
Default

Zone damper sticking


My downstairs HVAC system is divided into two zones, the main living areas and the master bedroom.

The damper for the main area occasionally does not open.



I notice this because the temperature drops and only a little air comes out of the registers. I imagine that before I notice this the heater has been going for a while trying to heat the place, so I'm sure this is costing me money.

I can go into the attic and hit the damper and it will open and work OK for a while.

Is this something that can be fixed or should I replace the whole thing?

By the way, I don't really like the zoning system because even with both zones active the bypass damper does not fully close.

D2.

Advertisement

Dutch2 is offline   Reply With Quote
Old 02-28-2010, 03:07 PM   #2
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,421
Rewards Points: 4,488
Default

Zone damper sticking


Depends on why its sticking.

Probably needs replaced.

The bypass probably doesn't close the whole way when both zones call because your short on return.

Advertisement

beenthere is offline   Reply With Quote
Old 02-28-2010, 03:14 PM   #3
Member
 
Join Date: Oct 2009
Location: NC
Posts: 31
Rewards Points: 25
Default

Zone damper sticking


I was just wondering if this is something I could lubricate or if this is the normal way these things stop working and it just need to be replaced.

I've been thinking about adding a return in the bedroom so the system works better when the door is closed, so it sounds like this would help it overall.

Is there a way to determine how "short on return" the system is? Can I measure the in & out temperature and calculate this?

Thanks,

D2.
Dutch2 is offline   Reply With Quote
Old 02-28-2010, 03:19 PM   #4
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,421
Rewards Points: 4,488
Default

Zone damper sticking


You can try oiling it. But, the motors are generally sealed bearings. So oil usually doesn't help. For more then a little while.

Yes, temp rise with both zone open can tell you how much air its moving. But not if its your return or supply that is lacking.

I said short on return. because that is the usual problem. it is possible that you are short on both supply and return, or just one or the other.

Best way to tell that is with a manometer, and check static pressure of both supply and return.

BTU output divided by (temp rise times 1.08) equals CFM.
beenthere is offline   Reply With Quote
Old 02-28-2010, 03:33 PM   #5
Member
 
Join Date: Oct 2009
Location: NC
Posts: 31
Rewards Points: 25
Default

Zone damper sticking


Thanks, I might try to oil the motor while I look for a replacement.

I looked in the furnace manual and it shows a CFM vs. temperature rise table. It seems if I measure the in and output temperature I can use this table to determine CFM?

I also have a CFM vs. External Static Pressure table for each of the 4 fan speeds, so if I know CFM and fan speed I could determine Static Pressure?

D2.
Dutch2 is offline   Reply With Quote
Old 02-28-2010, 03:49 PM   #6
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,421
Rewards Points: 4,488
Default

Zone damper sticking


Yes to your above questions.

But. it works better to measure each individual parameter. to get an accurate CFM.

EG: Check temp rise, calculate CFM. Check static, and check CFM against chart.

Advertisement

beenthere is offline   Reply With Quote
Reply


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
adding 3rd zone to honeywell trol-a-temp system bhelman HVAC 5 03-03-2010 05:11 PM
Adding new zone makapacs HVAC 0 11-26-2009 01:35 PM
need some help sorting out my new heating zone please wombosi Plumbing 3 04-23-2009 05:54 PM
help with third heat zone i just put in... wombosi HVAC 6 04-21-2009 01:02 PM
Zone damper system danstar25 HVAC 10 12-24-2008 02:27 AM




Top of Page | View New Posts