2nd Stage Heating issue

Reply

  #1  
Old 03-09-08, 03:19 AM
Member
Thread Starter
Join Date: Mar 2008
Posts: 5
2nd Stage Heating issue

Help...

I have a Keeprite VS90 Dueal Stage, Variable speed furnace tied to a Rogers 2 stage thermostat.

I use the t-stat to control the time till 2nd stage (it allows 5 min increments). I have it set to a 10 minute delay. I have noticed that the t-stat will kick in 2nd stage and within a minute the house is warm enough that the t-stat will stop the call for heat.

Am i better off setting the setting to a 15minute delay or using the 2nd stage for a short while. As well, what is the "normal" cycling temperature. the t-stat allows me to set when it will call for heat (after the temp. spread is greater than x degree).

I am located in Toronto, Canada - we hover around 27-35F

Thanks.
 
Sponsored Links
  #2  
Old 03-09-08, 07:13 AM
pflor's Avatar
Member
Join Date: Dec 2007
Location: U.S.A.
Posts: 1,127
A true 2-stage t-stat should automatically switchover from stage-1 to stage-2 as the house heating needs call for it...and switch back to stage-1 once the house starts warming-up. It should not keep the furnace running on its 2nd stage and the turn it off on stage-2.

Would you please post the full M/N of this t-stat?
You say is a Rogers. I suppose you mean White Rodgers.
 
  #3  
Old 03-09-08, 08:44 AM
Member
Thread Starter
Join Date: Mar 2008
Posts: 5
T-Stat Correction

Pflor, the correct info for the T-stat is:


Robertshaw 9815i

From what I can tell the T-stat calls for 2nd stage under either of the following conditions:

1. Current temperature of the house and the set temperature are greater than x degrees (x is user definable)
2. When the t-stat calls for heat for longer than x minutes (x is user definable, in 5 minute increments)

Thanks,
 
  #4  
Old 03-09-08, 03:49 PM
Jay11J's Avatar
Member
Join Date: Sep 2001
Location: Rochester, Minnesota
Posts: 18,427
I don't know that brand of stat, but if you got a timer, shut it off. Only allow the stat temp to cycle 2nd stage as needed.
 
  #5  
Old 03-09-08, 06:59 PM
pflor's Avatar
Member
Join Date: Dec 2007
Location: U.S.A.
Posts: 1,127
Hi...
please clarify:
I see from Robershaw that they have the following,
--> a 9825i2 t-stat, and a
--> a 9915i t-stat

But I don't see the 9815i you mention.
Please tell me which one of the two above is yours?
 
  #6  
Old 03-09-08, 07:51 PM
Member
Thread Starter
Join Date: Mar 2008
Posts: 5
T-Stat

Pflor - it is definetly a Robertshaw 9815i - I am looking at the manual that it came with. There are other 98xx models, but they are for heat pump units.


Jay11J - I am ok with killing the timer mode for 2nd stage, but based on history that would never activate 2nd stage - ever. The t-stat has an EER (Energy Efficient Recovery) mode - similar to a Honeywell adaptive reccovery. When EER is set to on, as it is, it holds 1st stage when returning to a warmer setting. therefore, house is 65 empty days, 70 occupied evenings - going from 65 to 70 would be held in 1st stage. turning off EER would force 2nd stage immediately upon activation of revory to 70, but albeit at a less efficient fuel usage than staying in 1st stage - or so Robertshaw says.

The current limit settings are 1degree for 1st stage and 2degree for 2nd stage to kick in


To be clear, I am in Canada - i have a Single Stage A/C, with the Keeprite 125,000 BTU furnace. The furnace is over-sized, as the I was told the typical for a 3500sq ft house (main and 2nd level - full basement not included in the sq. ft) is a 100,000btu unit.
 
  #7  
Old 03-09-08, 07:56 PM
Member
Thread Starter
Join Date: Mar 2008
Posts: 5
T-stat link

Here is the link to the Robertshaw catalogue showing the 9815i

http://www.robertshawtstats.com/imag.../150-1410K.pdf
 
  #8  
Old 03-10-08, 02:44 AM
pflor's Avatar
Member
Join Date: Dec 2007
Location: U.S.A.
Posts: 1,127
You sure seem to know what you're doing here, and you most certainly have done your homework and know your t-stat too...

Telling us that you are aware of your unit being oversized (for the size of your home) explains why would the t-stat stay on 1st stage at all times.
 
  #9  
Old 03-10-08, 03:23 AM
Member
Thread Starter
Join Date: Mar 2008
Posts: 5
As knowledable as I seem (thanks to the internet, and sites like this) I am still concerned about the whole 2nd stage thing. Although I paid cost (had a very good connection for the parts) I probably could have gotten a 1 stage 125btu unit.

seeing that i have what i have, is it ok to have the t-stat on a 1 degree setting or should it be at 1.5 prior to calling for heat

i had it at 1.5 and that is when i hit the 15min mark and had 2nd stage for all of 2 minutes - it didnt seem "good" to have it on for such a short time. at 1degree the unit cycles on and off more often but 2nd stage does not kick in.

So, which is better - 2nd stage kicking in for a few minutes each time, or 1st stage cycling more often?

Thanks in advance.
 
  #10  
Old 03-10-08, 05:36 AM
Jay11J's Avatar
Member
Join Date: Sep 2001
Location: Rochester, Minnesota
Posts: 18,427
For comfort, let the 1st stage run a long time, and as we said, just turn off the time, and let the stat itself cycle 2nd stage as needed.. I'd do 2˚ on 2nd stage, and 1˚ for 1st stage..
 
Reply

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


Thread Tools
Search this Thread
Display Modes