Fan Won't Shut Off On Heatpump. - 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 09-08-2009, 04:53 PM   #1
Newbie
 
Join Date: Sep 2009
Posts: 4
Rewards Points: 10
Default

Fan won't shut off on heatpump.


I have an FHP Geothermal heat pump system to heat/cool my upstairs living space. It is a split system in that the compressor is under the house and the coils and air handling unit is in the attic. I have noticed over the last several months that even though the compressor kicks off, the fan will continue blowing for hours before it will eventually kick off. I can even turn the unit to the off position (switch on my thermostat) and the fan will continue to run. I have a digital thermostat and have even tried unplugging the thermostat from the wall but the fan continues to run. I have tried a new thermostat as well but the problem perisists. The unit heats and cools just fine. Is there a relay in the unit that would cause this and if so is this something I can easily locate and replace myself? Any help or suggestions would be greatly appreciated.

Advertisement

MERCOPTIMAX is offline   Reply With Quote
Old 09-10-2009, 12:13 AM   #2
Newbie
 
Join Date: Apr 2009
Location: AZ
Posts: 9
Rewards Points: 10
Default

Fan won't shut off on heatpump.


I have the exact same problem! I was just about to try replacing the thermostat... I believe there is a relay on the fan, and it sounds like that has gone bad. I have never replaced one, so can't offer any advice. I'd probably hire someone to replace that... If you learn anything, please share.

Thanks,
Mark

Advertisement

beiley is offline   Reply With Quote
Old 09-10-2009, 08:25 AM   #3
Newbie
 
Join Date: Sep 2009
Posts: 4
Rewards Points: 10
Default

Fan won't shut off on heatpump.


Quote:
Originally Posted by beiley View Post
I have the exact same problem! I was just about to try replacing the thermostat... I believe there is a relay on the fan, and it sounds like that has gone bad. I have never replaced one, so can't offer any advice. I'd probably hire someone to replace that... If you learn anything, please share.

Thanks,
Mark
Hi Mark, I don't think replacing your thermostat will fix the problem and the reason I say that is becuase I have the exact same thermostat on my downstairs unit. I tried switching them but it did not fix the problem. Hopefully someone else will reply on this string who has had the same problem before and will advise more details on the fix. Thanks !!!
MERCOPTIMAX is offline   Reply With Quote
Old 09-11-2009, 10:43 AM   #4
Newbie
 
Join Date: Sep 2009
Posts: 4
Rewards Points: 10
Default

Fan won't shut off on heatpump.


Quote:
Originally Posted by beiley View Post
I have the exact same problem! I was just about to try replacing the thermostat... I believe there is a relay on the fan, and it sounds like that has gone bad. I have never replaced one, so can't offer any advice. I'd probably hire someone to replace that... If you learn anything, please share.

Thanks,
Mark

Mark, apparently this problem is a real stumper since no one has any suggestions on what the problem could be or a fix.
MERCOPTIMAX is offline   Reply With Quote
Old 09-16-2009, 09:45 PM   #5
Newbie
 
Join Date: Apr 2009
Location: AZ
Posts: 9
Rewards Points: 10
Default

Fan won't shut off on heatpump.


I called an AC repairman who came out today. Apparently on my blower there is a small circuit board that adds a delay when turning off the fan. He said that was usually the problem. He just bypassed that circuit board and that fixed my problem. I don't have the specific details on how to bypass it, but it looked easy for him to do it. He also mentioned that sometimes the relays 'stick'. They get burn marks on the contacts, and can stick, leaving on the blower. Doesn't sound like that was my problem, but it is another possibility.

Good luck,
Mark
--
Beiley Software
beiley is offline   Reply With Quote
Old 09-17-2009, 08:35 AM   #6
Newbie
 
Join Date: Sep 2009
Posts: 4
Rewards Points: 10
Default

Fan won't shut off on heatpump.


Quote:
Originally Posted by beiley View Post
I called an AC repairman who came out today. Apparently on my blower there is a small circuit board that adds a delay when turning off the fan. He said that was usually the problem. He just bypassed that circuit board and that fixed my problem. I don't have the specific details on how to bypass it, but it looked easy for him to do it. He also mentioned that sometimes the relays 'stick'. They get burn marks on the contacts, and can stick, leaving on the blower. Doesn't sound like that was my problem, but it is another possibility.

Good luck,
Mark
--
Beiley Software
Hi Mark,

Thanks for the update. I contacted the manufacturer of my unit and they said the possibilities were a circuit board (like you said) and that my unit heavily relied on relays. They felt like most likely mine was a relay sticking. I'll have to get a repair tech out to take a look. Sounds like yours was an easy fix. Pretty much just a rate per hour charge and that was it right? Thanks again for responding back.

Scott
MERCOPTIMAX is offline   Reply With Quote
Old 09-17-2009, 10:23 AM   #7
30 year tech
 
hvac122's Avatar
 
Join Date: Dec 2007
Location: Lincoln, Nebraska
Posts: 427
Rewards Points: 250
Default

Fan won't shut off on heatpump.


Surely the tech is going to replace the board and not just leave it by-passed? There is a reason it is there.
hvac122 is offline   Reply With Quote
Old 09-17-2009, 10:58 AM   #8
Newbie
 
Join Date: Apr 2009
Location: AZ
Posts: 9
Rewards Points: 10
Default

Fan won't shut off on heatpump.


I asked about that, wondering the same thing. He said it was meant to improve the efficiency slightly by delaying the blower turn on until about 1 minute after the compressor turns on, and keeping the blower on for about 1 minute after the compressor turns off. He said it was minor, and many of the newer blowers don't even have them. He thought it wasn't a big deal to run without that delay board. Do you have a different opinion?

Thanks,
Mark
--
Beiley Software
beiley is offline   Reply With Quote
Old 09-17-2009, 12:41 PM   #9
30 year tech
 
hvac122's Avatar
 
Join Date: Dec 2007
Location: Lincoln, Nebraska
Posts: 427
Rewards Points: 250
Default

Fan won't shut off on heatpump.


Efficiency is one reason for it. The other is for comfort. It takes a few minuites for the heat pump coil to get warm or cold depending on the season. The delay lets the coil do its thing so you don't get a blast of the wrong temperature air.

Also new units for the most part do all use this function. It may be adjustable as to how long the delay will be. Not sure on a FHP.

Advertisement

hvac122 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
Shut Off Valve won't shut off DIY_Dumbie Plumbing 1 07-11-2009 03:22 PM
Community water shut off zevon Plumbing 14 10-03-2008 08:16 AM
Toilet to Go won't shut off Evildad Plumbing 4 09-28-2008 01:26 PM
Best 1/2 inch water shut off valve. Nestor_Kelebay Plumbing 10 07-25-2008 12:16 PM
Toilet water Supply- Shut off valve kcreds Plumbing 5 04-07-2008 01:44 PM




Top of Page | View New Posts