Posted: 10/13/2011 3:36:44 PM EDT
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I have an old Williams wall heater in my downstairs rental that I can't keep lit. I think it's the thermocouple and have been trying to find a replacement. It's different than the thermocouples commonly available at Home Depot or even Grainger, though. On the thermocouple's pigtail, near the end that threads into the controller, is what appears to be a resistor with two spade terminals for wires from (maybe) the overtemp contoller on the heat exchanger. My understanding is that this is an emergency cut out (ECO). I tried looking up "thermocouple with ECO" online, and many are offered, but the pictures of all of them do not show the resistor-looking ox with two spade terminals that is on mine. What is the thermocouple that I need called in the trade? With the normal wires hooked up to the ECO, I could not get the pilot to stay lit. I then jumpered across the ECO. The pilot stayed lit. Then, the furnace fired up as normal. When it switched off, however, the pilot went out, and I cannot get it to stay lit, even with the jumper attached to the ECO. Can any of you explain to me what the problem might be or how to find out what it is? Second thing: I bought a programmable thermostat for it. I have only two wires to the old mechanical thermostat. One is red and one is yellow. None are labeled. The new thermostat has six terminals labeled as follows: O/B Y RC R G W To which terminals should I hook the two wires I have? Third thing: I probably need to clean this thing. What parts of a Williams wall furnace are most important to clean and how are they accessed? Thanks for any help you can offer. |
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I think what you need is part #P322391, you can get it off the Home Depot website, About $27.00. If the ECO is bad then you will have issues also. The ECO has resistance, try to bypass it by jumping will not work. [as you found out]
BTW, it's called a terminal block Thermocouple. I don't think it's really an ECO, I think it's more related to the vent damper. |
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Quoted:
I can't find the part her in town, so I cleaned and tightened all the connections. Now, it works fine, but only ith a jumper across the junction block on the thermocouple. Any advice? Thats telling you the issue is with the contacts at the hood damper or a bad eco. One does not defeat safeties in furnaces without realizing that bad things can happen. |
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Quoted: Quoted: I can't find the part her in town, so I cleaned and tightened all the connections. Now, it works fine, but only ith a jumper across the junction block on the thermocouple. Any advice? Thats telling you the issue is with the contacts at the hood damper or a bad eco. One does not defeat safeties in furnaces without realizing that bad things can happen. |
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Quoted:
Quoted:
Quoted:
I can't find the part her in town, so I cleaned and tightened all the connections. Now, it works fine, but only ith a jumper across the junction block on the thermocouple. Any advice? Thats telling you the issue is with the contacts at the hood damper or a bad eco. One does not defeat safeties in furnaces without realizing that bad things can happen. Yes, it opens up if there is a problem. |
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One more question, Knid sir: I get 0.1 ohm resistance on the cold sensor. Is that too much resistance? What does the specs say on it? If it's a switch, it should be 0000 closed, if there is supposed to be resistance, the specifications should be marked on it or available from the manufacturer. [if they are still around] If you can jump it and it works OK, I'm betting it's just a switch and not an actual ECO. |