Need Help Replacing 110V Electric Baseboard Thermostat...???


  #1  
Old 03-06-07, 06:24 PM
S
Member
Thread Starter
Join Date: Apr 2005
Location: usa
Posts: 51
Upvotes: 0
Received 0 Upvotes on 0 Posts
Need Help Replacing 110V Electric Baseboard Thermostat...???

I'm trying to replace one of those old mercury switch thermostats.
I have hot water baseboard heating.

The original thermostat is a Honeywell type t451a.
On the inside case it says:
rating in amperes 120 vac 208/240 vac
fl =8 lr = 48 fl=4 lr=24
pilot duty 125v
7.2 a Res at 277 vac

I tried conecting a Honeywell RLV430A that I bought from Home Depot. I thought it would work, but it didn't.... It said it is meant for electric baseboard heating.

There are only two wires(both black) on the new unit. I conected them but nothing happened. The wires in the wall are 12 guage.
Nothing appeared on the LCD and no heat came on.

Here's the strange part, or at least I think. I tested the line w/ a voltmeter and it only tested about 25v...??
Does this mean I have a 24v system? I'm confused.

I put the original one back in and it works fine.

Anyway, what am I doing wrong?? AM i trying to replace it w/ the wrong unit.

THanks
 

Last edited by sandonn; 03-07-07 at 04:03 AM.
  #2  
Old 03-07-07, 06:46 AM
Jay11J's Avatar
Member
Join Date: Sep 2001
Location: Rochester, Minnesota
Posts: 18,248
Upvotes: 0
Received 0 Upvotes on 0 Posts
Are you able to trace theh wire back down to the boiler and see if the wire is coming off a 24 volts transformer?

Otherwise post a pix of us to see.
 
  #3  
Old 03-07-07, 09:26 AM
Ed Imeduc's Avatar
Member
Join Date: Aug 2002
Location: Mountain Williams Missouri
Posts: 18,005
Upvotes: 0
Received 1 Upvote on 1 Post
Wink

Look out what you are doing here.

I have hot water baseboard heating.

It said it is meant for electric baseboard heating.
lets not mix the two .
Get the right tstat for sure

I put the original one back in and it works fine.

If its not broke Dont fix it
 
  #4  
Old 03-07-07, 07:06 PM
S
Member
Thread Starter
Join Date: Apr 2005
Location: usa
Posts: 51
Upvotes: 0
Received 0 Upvotes on 0 Posts
I couldn't tell if it is coming off of a transformer. So I took a bunch of pictures.
I couldn't figure out how to attach them, if there is a way. So just posted the links...

http://i125.photobucket.com/albums/p42/rnachmann/1.jpg
http://i125.photobucket.com/albums/p42/rnachmann/2-1.jpg
http://i125.photobucket.com/albums/p42/rnachmann/3.jpg
http://i125.photobucket.com/albums/p42/rnachmann/4.jpg
http://i125.photobucket.com/albums/p42/rnachmann/5.jpg
http://i125.photobucket.com/albums/p42/rnachmann/6.jpg
http://i125.photobucket.com/albums/p42/rnachmann/7.jpg

As far as the electric/hot water thing. I think I'm just a little confused on the proper terminology.
I have hot water baseboard heating which i thought was 110/220 because of the 12 guage wire in the wall.
But after testing it to 24v w/ the multimeter, I guess it is 24v low voltage...?
But, why does it still have the 12 guage wire then??

I hope the pictures help. If you need any more pics/info, let me know.

Thanks
 
  #5  
Old 03-07-07, 08:31 PM
Jay11J's Avatar
Member
Join Date: Sep 2001
Location: Rochester, Minnesota
Posts: 18,248
Upvotes: 0
Received 0 Upvotes on 0 Posts
I saw the transfromer on the left hand side of the pump, so you got low voltage.

maybe at one time the boiler did use line voltage, and was later changed over to low.

So, return the t-stat and get a Honeywell Vision Line t-stat.
 
  #6  
Old 03-07-07, 09:00 PM
S
Member
Thread Starter
Join Date: Apr 2005
Location: usa
Posts: 51
Upvotes: 0
Received 0 Upvotes on 0 Posts
Jay,
Can you give me an idea of the type of Honeywell model I should get. Model #...??

Also, how is this going to work.
My understanding of 110 systems is that the 2 electric cables going to the thermostat complete the switch. Or the thermostat completes the switch when it gets cold enough to turn on.
In low voltage systems, the power is always conected, but the aquastat uses the low voltage signal from the thermostat to turn the heater on or off?
Is my understanding somehwat correct?

Anyway, w/ that in mind. When I buy a "low voltage" tstat, how many cables need to be conected. Because i only have the 12-2 romex. I thought the low volt needed 3 cables?

In this picture is the transformer right in the middle, and the pump to the left?
http://i125.photobucket.com/albums/p42/rnachmann/8.jpg

Thanks Again
 
  #7  
Old 03-07-07, 09:40 PM
S
Member
Thread Starter
Join Date: Apr 2005
Location: usa
Posts: 51
Upvotes: 0
Received 0 Upvotes on 0 Posts
I found a honeywell vision tstat.
How's this one?
http://www.amazon.com/Honeywell-Vision-Conventional-Programmable-Thermostat/dp/B000BPC2BO/ref=sr_1_14/102-2142638-0736125?ie=UTF8&s=home-garden&qid=1173328804&sr=8-14
 
  #8  
Old 03-08-07, 04:50 AM
Jay11J's Avatar
Member
Join Date: Sep 2001
Location: Rochester, Minnesota
Posts: 18,248
Upvotes: 0
Received 0 Upvotes on 0 Posts
The t-stat complete the ciricert to turn on the system or off.

You will only need 2 wires R and W.. and then use the battery to keep the t-stat going. Just rember to change it every fall.

Yes, that is the t-stat I am suggesting.. You will see them in the same area in Home Depot that you got the last t-stat.

That boiler is pretty old.. When was the last time you had an oil service tech out to give it a full tune up and filter and nozzel change?
 
  #9  
Old 03-08-07, 05:06 AM
S
Member
Thread Starter
Join Date: Apr 2005
Location: usa
Posts: 51
Upvotes: 0
Received 0 Upvotes on 0 Posts
OK, I going to go to Home Depot today.

I have a contract w/ Petro. They come out once a year to service it. They were just out 2 months ago.

thanks.

I'll let you know how it goes
 
  #10  
Old 03-09-07, 06:46 PM
S
Member
Thread Starter
Join Date: Apr 2005
Location: usa
Posts: 51
Upvotes: 0
Received 0 Upvotes on 0 Posts
Bought the new thermostat and it works!!!

Thanks again for your help
 
 

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