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November 6, 2009
Furnace or Thermostat Issues
My furnace is not turning off. The temp is kept at around 68-70. Two days ago, I woke up to 82 degrees due to the furnace not stopping, thermostat was set to 68. I shut the heat off from the thermostat and reset it. Yesterday, I replaced the batteries. This evening, I turned on the heat and it kick off and continued to run up to 7 degrees, even when the thermostat was set at 68. Again I set the thermostat to off and reset it. This was not an issue back in early October, when we go some cold days, the furnace/thermostat was running ok for about 1-2 weeks. Any ideas? or Technician recommendations?
Comments
sounds like you have a short in the stat wiring or a defective thermostat..did you replace the thermostat and not set the new stats settings to the appropriate mode?
Posted by: eman1234 at November 5, 2009 9:42 PM
No, the thermostat has not been replaced. It's an inexpensive lux 500, I have no idea how old it is or when it was installed. The furnace is pretty old, probably over 20 years as per a check done by keyspand 2-3 years ago. I might try to buy the same thermostat and replace, however, i'm not a handy person. I'm just afraid that the issue might be something more serious and I will not be able to find the right person to check this out this late during the season.
Posted by: gates_ave at November 5, 2009 10:39 PM
i could take a look at it...i am a boiler guy, not a furnace guy...email me at errol832000@yahoo.com for a free consultation
Posted by: eman1234 at November 5, 2009 10:59 PM
I'm certainly not an expert, but I've lived with a furnace since the mid-70s. The thermostat is basically a switch. The furnace will not run if the switch is off--there'd be no power to the fan, among other things. Therefore the switch (thermostat) must not be working. It shouldn't be that big of a repair job. If all else fails National Grid has a (fairly expensive) repair service.
Posted by: Bob Marvin at November 6, 2009 9:53 AM
Definitely sounds like the thermostat. You really don't need to be handy to replace it. It you buy the same kind of device you can reuse the screw holes. Leave the plate from the old one on until you're ready to connect the new one, that way you'll see exactly where the wires should go; if it's just heat there are only two.
I put a new thermostat in myself last night after work. It didn't take long. The replacement model was a Honeywell with these incredibly tiny screws to connect the two wires (so I wouldn't really recommend that particular type). I ended up using the screw driver from one of those glasses repair kits I bought at a dollar store.
Posted by: bessie2 at November 6, 2009 10:02 AM
eman,
do you install boiler flue dampers? Do you do light electrical?
Posted by: slopefarm at November 6, 2009 10:59 AM
I also just replaced my thermostat from the old "circle" non-programmable kind to a programmable digital thermostat. Very easy, and definitely DIY. The new thermostat was only about $40; the back panel had oblong screw holes so that it would fit into a wide range of existing screws, so I didn't even have to drill new holes.
Posted by: brooklynstyle at November 6, 2009 11:39 AM
Thermostat is definitely diy. Generally 2 wires, no danger of doing something terribly wrong. A common test is it take out the thermostat and connect the 2 wires together, basically forcing the connection / keeping the switch ON and calling for heat. Buy a digital programmable one and swap it out.
Whatever you do, avoid calling for service on the weekend. Last year my forced air furnace crapped out on a freezing Friday night. I got somebody there on Saturday who charged $200 (cash, minimum for showing up on Saturday). He diagnosed the problem, a bad fan limit switch was tripping the electrical circuit, and quoted over a thousand bucks to replace it! (Criminals!) I bought the part on Monday morning from the supply house for 80 bucks and got a # of a tech to call - Chris Quartana 646-996-3436
Paid him something like 150 bucks for the labor to put it in.
Posted by: Bklnite at November 6, 2009 12:06 PM
Thanks all for the helpful comments. I just ordered the replacement programmable thermostat (same mode) and will be changing it myself and check if it does the trick. Thanks again.
Posted by: gates_ave at November 6, 2009 1:25 PM
Gates, do you also have central air? Also, please make sure when you take the thermostat off that you only have two wires and not four. Even though there are batteries, they could be a back up and your thermostat could be hard wired as well.
Posted by: Brooklyn Plumber at November 6, 2009 5:54 PM
I would definitely have it checked. It's better that way instead of repairing it yourself.
http://www.thehardwarecity.com/getProductDetail.html?sku=5295076
Posted by: blackeyed at November 7, 2009 4:33 AM
I just replaced the thermostat and it cycled well and turned off. I found out the furnace is 55 years old, 1954. Hopefully this keeps the furnace going for another winter.
Posted by: gates_ave at November 13, 2009 11:26 PM
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