I'm Just Sayin' - Using a plug-in Thermo for AC On/Off


  #1  
Old 05-27-09, 10:40 AM
H
Member
Thread Starter
Join Date: Dec 2008
Location: IE in the SoCal
Posts: 12
Upvotes: 0
Received 0 Upvotes on 0 Posts
I'm Just Sayin' - Using a plug-in Thermo for AC On/Off

I have a Day/Night system and the air handler is on its last leg.

I’m trying to squeeze another season or two out of it. I think I have a fan relay out and am looking for a replacement. Short of that, a new control board costs $300-$400.

I have the blower fan problem – where it does not shut off. The outside compressor works fine; it blows cold air and even hot air. We used it this past winter by plugging it in/unplugging it.

I tried replacing the transformer, but the problem still exists.

Since I don’t want to throw $400 at the system I know will need to be replaced soon, how about using a plug-in thermostat timer/switch?
The kind used in greenhouses, the switches are rated at 15A max.

Plugging the unit into the plug-in thermostat and using it to power the system on/off.

Is something like that safe, as far as the AC unit draw? I believe the blower motor is a 6A draw.

Here is a link to the ACF 120v Programmable Plug-in Thermostat, the item for $59.95.

Thoughts please?

Greenhouse Controls - Thermostat Controllers from ACF Greenhouses
 
  #2  
Old 05-27-09, 11:04 AM
D
Member
Join Date: Aug 2007
Posts: 1,851
Upvotes: 0
Received 0 Upvotes on 0 Posts
What kind of heat do you have? What is the part number on the fan board? Does it look like any of these?

Bryant Carrier Control Boards

Bryant and Day and Night are the same thing.
 
  #3  
Old 05-27-09, 11:16 AM
mattison's Avatar
Member
Join Date: Mar 2003
Location: Cinti, OH
Posts: 5,315
Upvotes: 0
Received 1 Upvote on 1 Post
It would be easier to just get a fan relay and install it on the side. I doubt it's code to have your furnace on a convienience plug.


On the otherside if you're going to replace it in a year then you could just leave it the way it is. That blower is probably only costing you $4-$5 bucks a month to run 24/7 if that much.
 
  #4  
Old 05-27-09, 12:43 PM
H
Member
Thread Starter
Join Date: Dec 2008
Location: IE in the SoCal
Posts: 12
Upvotes: 0
Received 0 Upvotes on 0 Posts
Originally Posted by daddyjohn
What kind of heat do you have? What is the part number on the fan board? Does it look like any of these?

Bryant Carrier Control Boards

Bryant and Day and Night are the same thing.
Thanks daddyjohn, I think it's in there for about $125. That makes it more feasible.

I really don't know much about electrical circuits and troubleshooting; and my guess about it being a bad relay is based on my research here and elsewhere.

I see two relay contactors on the board - and one kicks on at power, I can see the contacts closing and opening; on the other relay it appears the contacts are shut, if I tap it with a screw driver, I see a spark but they do not open.
 
  #5  
Old 05-27-09, 12:52 PM
H
Member
Thread Starter
Join Date: Dec 2008
Location: IE in the SoCal
Posts: 12
Upvotes: 0
Received 0 Upvotes on 0 Posts
Originally Posted by mattison
It would be easier to just get a fan relay and install it on the side. I doubt it's code to have your furnace on a convienience plug.


On the otherside if you're going to replace it in a year then you could just leave it the way it is. That blower is probably only costing you $4-$5 bucks a month to run 24/7 if that much.
Yeah, I know it's not code.

Last summer I tried to run the fan 24/7, but it ate up a lot more than $4-5; it was more like $100 or so, and I stopped doing that (and it's only a 2 yr old fan motor, so it's not an old electric hog).

Then I put it on a 15-amp timer, and started wondering if it is safe or not.

This season I am revisiting the idea of repairing it correctly, but I also know that I can nickel and dime it into several hundred dollars by buying part after part.

I'll probably roll the dice once more and see if it's the board.

The question stands though - is it unsafe to run the unit off of any type of plug-in timer?

Thanks again, this board rocks
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: