Furnace issues

[DaleT]

I have a problem and with the well rounded folks here I thought I see if anyone could help.<br /><br />What happes is the pilot light keeps going out. It will relight every time with no problems, following the manufacturers instructions. The problem is after the furnace cycles through once, turns on and heats house to thermostat setting, the pilot goes out. It then has to be relit. My thinking is the gas valve, as the pilot will stay lit as long as the furnace does not engage. Any thoughts or suggestions would be appreciated. <br /> Thanks, Dale

 

[Snookster]

Re: Furnace issues

Dale, a number of events can bring this on. Remember, the pilot is only held on via milavolts generated via the dis-simular metals expanding against each other wrapped in the body of the thermocouple.<br /><br />What you're describing is a drop in voltage once the unit starts. This is often a result of a partially clogged pilot orifice (hardley the dia. of a sewwing pin) or a rusted off air diverter that used to be in front of the pilot assembly -- what happens is the inrush of cold combustion air when the buner fires cools the thermocouple off to the point it drops out the safety valve.<br /><br /><br />1. Gently remove the thermocouple from the body of the gas valve. Clean the female hole in the valve with a Q tip, if corroded, try a very light sandcloth.<br />2. Clean the male end of the thermocouple the same way.<br />3. Be sure the thermocouple is emersed at least 1/2 of the body in the pilot flame.<br />4. Thier is usually a cap on the gas valve marked pres. adj, once removed - a long slender srewdriver is required to adj the pilot flame.<br />5. Change the thermocouple.<br /><br />If you don't feel comfortable making these minor adj-- pls don't try, call a lic co. - you could be taking your families life in your hands.

 

[artherm]

Re: Furnace issues

Dale, The Snookster makes some very good points. I am a Salesman for a Heating/Air Conditioning Wholesale Distributor. We do not encourage homeowners performing this type of maintenance. It is dangerous as the Snookster points out. If you do something wrong that you are not comfortable with, you could be endangering the lives of your family as well as burning your house down. In my experience the symtoms that you describe indicate a defective gas valve. We wholesale a standing pilot valve for $35.00. A Licensed HVAC Service company will probably charge you somewhere around $150-200.00 for the repair and furnace check. The integrity of your heat exchanger should also be checked. A defect here would allow deadly carbon monoxide into your home, requiring a furnace change. I would leave this work to the experts. Good Luck.

 

[DaleT]

Re: Furnace issues

Thanks for the info. To be honest I won't attempt these repairs myself, just not comfortable, but I like to have an idea of what is going on when paying someone else to the work.

 

[radar750]

Re: Furnace issues

Dale, Your post title says you are having Furnace problems.Generaly speaking just about everyone calls their heating system a FURNACE when it may in fact be a BOILER. Do you have vents where hot air blows out which is called Forced hot air? or do you have raditaors or baseboard that carries water or steam? <br />If you have Forced hot air by Gas or Propane and your pilot is out 99% of the time is is the thermocouple. However a bad thermocouple will NOT relight. Chronic pilot outage is a sign of a crack or hole in your heatexchanger and will allow carbon monoxide into your house.I will give you a kind of check list to check.<br />First let me say that everyone should have a very good CO detector, not some piece of junk from home depot for $50 spend the money for a good one and there should be one on every floor.<br /><br />1.If you have a Pilot out and it will not relight you should change thermocouple and clean pilot and blow out pilot tube. If after doing that it still will not light than you need a new gas valve.<br />Do NOT attempt to adjust your own gas pressure unless you have a manometer and know what you are doing. I think snook ment to try to adjust your pilot flame size which is different and I also dont reccomend you doing that either.That would help if you had a borderline thermocouple and giving it some more heat may get you through but that is not the answer.<br />2 If your pilot is out and you can simply relight it and it holds on then chances are you have a bad gas valve. Thermocouples can be weak but most of the time they either work or they dont.<br />Dale can you see/watch the flame in your furnace?<br />If you can, watch the flame come on and then wait for the blower to kick on. Look for any change in the flame such as rolling out or change in color, if that happens you have a crack or hole in the heat exchanger and the unit should be replaced.<br />If you do not have a CO detector the fire dept can check the level in your house.<br />If you do happen to have a boiler then forget everything I said about the cracks and flame. Let me know what you have and I will try to help you.

 

[crab bait]

Re: Furnace issues

what & where & is,, a 'good' CO detector..