Erratic Thermostat Being Warmed Behind From Wires? - Electrical - DIY Chatroom Home Improvement Forum

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


Thread Tools Display Modes
Old 10-21-2012, 10:31 AM   #1
Join Date: Oct 2012
Posts: 1
Rewards Points: 10

erratic thermostat being warmed behind from wires?

Hi there,

I am in a funky (owner-built in the 50s, 'summer home') rental house with electric baseboard heat. One of the thermostats (double pole) was an old piece of junk and impossible to control and very inaccurate. I replaced it with a newer honeywell double pole thermostat and am experiencing the same problems. It kicks off too early and then even if you turn it up to 85 and it's 65 in the room it wont kick back on for a while (no click either). I had a theory that it was actually getting too warm from the wires because they've got two six foot and one four footer running off of this and I believe they are running at 120V (220 would have more than 1 white and 1 black wire, right? -- in the junction box that's all there is on the load side/line side respectively). There's no labeling inside these baseboard heaters but online research has told me to estimate the total wattage as 4000 watts.

I felt the thermostat and it was warm to the touch when the house was 65 and it refused to kick on even when turned all the way up (but 30 minutes later, once the wires cooled my bet, it would kick on just fine). So I'm pretty sure this is indeed what is happening (wires too warm).

So, questions:

1.) Is this normal behavior or does it indicate that something is overloaded/wrong with the wiring?
2.) Is reducing the load by disconnecting the 4 foot unit from the sequence likely to make a difference (theoretically bringing it down to 3000 watts -- which also allows me to use nicer, cheaper, digital programmable thermostats)?


hbirch is offline   Reply With Quote
Old 10-21-2012, 12:19 PM   #2
Join Date: Nov 2007
Location: Nashua, NH, USA
Posts: 7,971
Rewards Points: 1,548

A 220 (240) volt only appliance can be run off of just black and white wires connected up to a double breaker installed in the panel so as to have 240 volts between the two breaker terminals. (You may find two single breakers in older installations.)

If the wires are too thin, then they will heat up excessively. A 12 gauge wire can handle 16 amps at either 120 or 240 volts continuously. A 14 gauge wire can handle 12-1/2 amps continuously.

If the thermostat or switch assembly is noticeably warm you should also check for and tighten up any loose connections.


The good conscientious technician or serviceperson will carry extra oils and lubricants in case the new pump did not come with oil or the oil was accidentally spilled, so the service call can be completed without an extra visit.

Last edited by AllanJ; 10-21-2012 at 12:24 PM.
AllanJ is offline   Reply With Quote

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
Question about connecting wires to the RTH2300 (honeywell) thermostat crap_at_diy HVAC 3 11-26-2011 10:50 PM
Honeywell Prestige HD thermostat wiring 1H/1C + Humidification System TekGamer HVAC 0 07-09-2010 11:58 PM
2 stage thermostat with old wiring (4 wires)? bigbug HVAC 2 06-22-2010 12:34 PM
Problem with Lennox Pulse Furnace Wiring to Thermostat scalvin Electrical 4 12-30-2009 07:48 PM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1