|Description of Problem:||Can’t light the furnace pilot (Coleman 4023-5871, looks great otherwise and worked just a few month ago when it wasn’t needed; the blower works great). Opened it, apparently the thermocouple is broken. Would like to purchase a replacement – or maybe I should replace the entire valve assembly? Please advise.Thank you!|
Hi: Well the gas valve is very likely no longer available. Does the pilot work as long as you hold the button in?
If so, the broken thermocouple is probably all you need to repair. If the pilot flame does not keep the t-couple hot of course the flame will go out, the power from the t-couple replaces your finger on the safety valve to keep the valve open, by passing a very small current through a solenoid coil in the valve to keep it open.
Any t-couple will work as long as it is long enough to sit in the flame and mechanically connect to the gas valve. They all provide the same voltage about 18 to 29 millivolts. The physical connection to the gas valve (most are very similar), should never be over-tightened in the threaded portion, a rule of thumb is finger tight plus a MAXIMUM of 1/4 turn. If the pilot stays lit then the gas valve should work OK, they rarely are the problem thankfully.
Hope this will help. Universal t-couple are usually available, but as I am closed for the season and do not have my catalogues I cannot tell you which one to purchase.