Can't get our heater to turn off UPDATE

trmiv

Lifer
Oct 10, 1999
14,670
18
81
So my wife and I just bought our first house recently (built in 2000, so not brand new). Anyway, we closed on October 30th and on Halloween my wife wanted to go the new house and hand out candy even though we aren't moved in yet. I get there and notice the AC is on (it was like 58 outside), so I turn the thermostat to Off and it shuts off.

Well we leave that night and three days later go back to the house to move some stuff in and it's 97 degrees in the house and the heater is running! I go check the thermostat (digital) and it's still set to off. So my Dad and I fiddle with it and get the heater turned off and leave the thermostat set to off. That was Sunday evening.

So last night I head back over to the house to do a few things, I open the door and I'm greeted by a blast of heat. It was 104 degrees in the house! 104! And the frigging heater was still going full blast.So my Dad comes over and we look around and figure out that the heater will turn on just fine with the thermostat, but won't turn off once it gets over the set point. So say I set the thermostat to 75 and it gets to 74 in the house, the heater clicks on. But once it gets over 75, it never shuts off. The other odd thing is, the heater will just come on by itself if the thermostat is set to the "Off" position. I ended up switching off the breaker to the heater so the frigging thing can't turn on at all.

Any idea what could cause this? If it's something simple and cheap that my Dad and I can fix I won't bother calling the home warranty in, but otherwise I'll need to get them involved.

I can't wait to see that first electric bill though. :(

UPDATE:
OK so I changed the thermostat and it didn't make a difference. But I've found that with either thermostat I can get the heater to work sometimes. Last night I had the thermostat set at 70 and it worked just fine for hours, shutting off at 71 and clicking back on at 69. Then when I was going to bed I went upstairs and it was a bit warm so I came back down and set the thermostat to 68. The room temp at that time was 70. I heard it click off and the fan and heat pump shut off, so I walk upstairs and just as I get to the top I hear it pop itself back on. Keep in mind the thermostat was set to 68 and it was 70 at that time. So I went back down and tried to turn it off and it wouldn't turn off again even if it was set to Off. I ended up having to shut off the breaker to get it off. Why would it work fine for awhile and then start behaving like that? It does this with either the old or the new thermostat.
 

FoBoT

No Lifer
Apr 30, 2001
63,084
15
81
fobot.com
replace the thermostat

they range in price from $20-$100 at home despot/lowes

only tool required is a screwdriver
 

Demon-Xanth

Lifer
Feb 15, 2000
20,551
2
81
Likelyhood #1:
Thermostat

#2:
Relay

#3:
Your wife is cold

Easy way to check #1 is to remove the two wires going to the thermostat, if it still comes on, there's a relay problem. But likely #3 is still going to be a problem as your wife is going to be cold until the temperature is high enough to do IR soldering by passing boards through your house.

Edit:
Another possibility is that you have a gate to hell that occasionally springs open, you'll need to go to your local theological supply store to pick up a replacement latch. They do wear out from time to time and have been known to cause things to get hot enough to burn down. Don't block the door completely because those demons really know how to make a great bacon and eggs breakfast, even if they do burn the toast most of the time.
 

amdskip

Lifer
Jan 6, 2001
22,530
13
81
There should be more than 2 wires going to the thermostat, more like 4 or 5. See if they are labeled when you remove the front face of the thermostat. Color means pretty much nothing. Before removing any wires, make a note of where they are currently hooked up to or take a picture for future reference.
 

ultimatebob

Lifer
Jul 1, 2001
25,134
2,450
126
Originally posted by: FoBoT
replace the thermostat

they range in price from $20-$100 at home despot/lowes

only tool required is a screwdriver

Just make sure to turn off the breaker first if it's an electric heater. :)
 

trmiv

Lifer
Oct 10, 1999
14,670
18
81
Originally posted by: amdskip
There should be more than 2 wires going to the thermostat, more like 4 or 5. See if they are labeled when you remove the front face of the thermostat. Color means pretty much nothing. Before removing any wires, make a note of where they are currently hooked up to or take a picture for future reference.

Yea there are quite a few wires. I assume the others are from the AC?
 

waggy

No Lifer
Dec 14, 2000
68,143
10
81
Originally posted by: trmiv
Originally posted by: amdskip
There should be more than 2 wires going to the thermostat, more like 4 or 5. See if they are labeled when you remove the front face of the thermostat. Color means pretty much nothing. Before removing any wires, make a note of where they are currently hooked up to or take a picture for future reference.

Yea there are quite a few wires. I assume the others are from the AC?

yeap.

its very easy to fix. hell i did it!
 

PingSpike

Lifer
Feb 25, 2004
21,758
603
126
Originally posted by: Demon-Xanth
Likelyhood #1:
Thermostat

#2:
Relay

#3:
Your wife is cold

Easy way to check #1 is to remove the two wires going to the thermostat, if it still comes on, there's a relay problem. But likely #3 is still going to be a problem as your wife is going to be cold until the temperature is high enough to do IR soldering by passing boards through your house.

Edit:
Another possibility is that you have a gate to hell that occasionally springs open, you'll need to go to your local theological supply store to pick up a replacement latch. They do wear out from time to time and have been known to cause things to get hot enough to burn down. Don't block the door completely because those demons really know how to make a great bacon and eggs breakfast, even if they do burn the toast most of the time.

Number 3 can be solved sometimes when you're in bed if you allow your wife to put her ice cold feet on yours causing your legs to freeze solid and shatter to pieces.
 

trmiv

Lifer
Oct 10, 1999
14,670
18
81
I guess I'll try to replace the thermostat. I wanted to get a programmable one anyway, the one on there is very basic. Ahh the joys of home ownership!

 

Jugernot

Diamond Member
Oct 12, 1999
6,889
0
0
Furnace or Boiler? It you have a boiler, you could have a zone valve stuck open. When they go bad, their default position is open.
 

waggy

No Lifer
Dec 14, 2000
68,143
10
81
Originally posted by: trmiv
I guess I'll try to replace the thermostat. I wanted to get a programmable one anyway, the one on there is very basic. Ahh the joys of home ownership!

pfft replacing the thermostat is minor.

in the last 4 years we have replaced, washer, dryer, fridge, stove, dishwasher, heating unit, and half the windows and hopefully next summer the roof!

oh and th thermostat. we wanted a programmable one also.


if i didn't have to live in a house i would have a bunch of extra money LOL
 

Chryso

Diamond Member
Nov 23, 2004
4,039
13
81
I would bet that the old owners had a programmable one and they took it with them and threw the current one in at the last minute.
 

spidey07

No Lifer
Aug 4, 2000
65,469
5
76
Originally posted by: Chryso
I would bet that the old owners had a programmable one and they took it with them and threw the current one in at the last minute.

Brilliant! Probably true.

Thermostat is just miss wired.
 

0roo0roo

No Lifer
Sep 21, 2002
64,795
84
91
Originally posted by: waggy
Originally posted by: trmiv
I guess I'll try to replace the thermostat. I wanted to get a programmable one anyway, the one on there is very basic. Ahh the joys of home ownership!

pfft replacing the thermostat is minor.

in the last 4 years we have replaced, washer, dryer, fridge, stove, dishwasher, heating unit, and half the windows and hopefully next summer the roof!

oh and th thermostat. we wanted a programmable one also.


if i didn't have to live in a house i would have a bunch of extra money LOL

yea its just 2 or 3 wires...easy.
 

trmiv

Lifer
Oct 10, 1999
14,670
18
81
OK so I changed the thermostat and it didn't make a difference. But I've found that with either thermostat I can get the heater to work sometimes. Last night I had the thermostat set at 70 and it worked just fine for hours, shutting off at 71 and clicking back on at 69. Then when I was going to bed I went upstairs and it was a bit warm so I came back down and set the thermostat to 68. The room temp at that time was 70. I heard it click off and the fan and heat pump shut off, so I walk upstairs and just as I get to the top I hear it pop itself back on. Keep in mind the thermostat was set to 68 and it was 70 at that time. So I went back down and tried to turn it off and it wouldn't turn off again even if it was set to Off. I ended up having to shut off the breaker to get it off. Why would it work fine for awhile and then start behaving like that? It does this with either the old or the new thermostat.
 

MrPickins

Diamond Member
May 24, 2003
9,125
792
126
Originally posted by: PingSpike
Number 3 can be solved sometimes when you're in bed if you allow your wife to put her ice cold feet on yours causing your legs to freeze solid and shatter to pieces.


:laugh:

So true.
 

Demon-Xanth

Lifer
Feb 15, 2000
20,551
2
81
The fan will operate for a time after the heater stops to make sure the heating coils don't overheat. There are snap switches inside the heater that will close when the air gets to a certain temperature to keep the fan going, then when it cools down enough, they open up and the fan stops.
 

trmiv

Lifer
Oct 10, 1999
14,670
18
81
Originally posted by: Demon-Xanth
The fan will operate for a time after the heater stops to make sure the heating coils don't overheat. There are snap switches inside the heater that will close when the air gets to a certain temperature to keep the fan going, then when it cools down enough, they open up and the fan stops.

It the scenario I described above it never turns off. Plus heat is still coming out. When the room was 70 and I set the thermostat to 68 it shut off, heat pump and fan. Not 45 seconds later with the room the same exact temp it popped back on by itself and I couldn't get it to turn off without shutting the breaker off.