Cozy LP wall furnace pilot won't stay on
#1
01-29-18, 08:19 AM
Cozy LP wall furnace pilot won't stay on
It's a 20 year-old Cozy W506E/L.P. Sometimes it will stay on for just one cycle. Sometimes for a day or so. Intermittent problems are hard to diagnose, and it's driving me crazy! I'm having some difficulty finding out if replacement parts are even available -- The gas valve is my prime suspect right now, but I can't find a cross reference (VS821A1556 L.P. M-Volt).
#2
01-29-18, 09:13 AM
Group Moderator
Before the gas valve I would suspect the thermopile. It's the metal tube in the flame of your pilot light. If it's dirty or the flame is not hitting it properly it can't generate enough current to open the gas valve. They also go bad with age and yours may simply need to be replaced. The good news is that they are rather generic so a gas stove service person might recognize what part you need.
#3
01-29-18, 12:34 PM
That gas valve is a Honeywell 750 millivolt gas valve. A company called Johnstone Supply carries Cozy replacement parts. Use any search engine to find the parts. As Pilot Dane wrote, the problem is probably in the pilot being dirty or the thermopile generator needs replaced
#4
01-29-18, 04:24 PM
Group Moderator
Wow... I had a whole reply typed up and it's gone. 
Parts are still available for that wall furnace.
The link below is the manual with parts list.
cozy heaters/uploads/PDF/GWF_Manual.pdf
The thermopile is a part # 70098. There are many subs for it.
70098-gas-pilot-generator-natural-gas-oem-45217
johnstone supply/product-view.ep?pID=L44-905
Monessen-26D0566-Fireplace-Thermopile-Thermogenerator
Parts are still available for that wall furnace.
The link below is the manual with parts list.
cozy heaters/uploads/PDF/GWF_Manual.pdf
The thermopile is a part # 70098. There are many subs for it.
70098-gas-pilot-generator-natural-gas-oem-45217
johnstone supply/product-view.ep?pID=L44-905
Monessen-26D0566-Fireplace-Thermopile-Thermogenerator
#5
01-30-18, 07:53 AM
Thank you for all of the helpful suggestions. I did install a new thermopile (using a "generic" 750 mv part, as opposed to a direct replacement). That didn't seem to help, but maybe I need to get the approved one? I have also removed and cleaned the burner. Now I would note that the "hood" over the pilot flame is pretty deteriorated, but the flame still seems to cover the thermopile pretty well. Again, finding a replacement has proved elusive (I will definitely look at the Johnstone Supply link), because the bracket style of mine seems to be obsolete. Something else I didn't include before: The pilot adjustment on the valve itself doesn't work. The flame stays the same size no matter what adjustment I make.
#6
01-30-18, 04:04 PM
Adjusting the size of the pilot flame at the gas valve, it is probably adjusted to maximum. You will have to turn the small screw clockwise to get any change in the flame size. Make sure that any wiring and all the wire connections are clean and tight and that the thermostat if you have one is the correct type for a powerpile system. A standard thermostat usually will not work. Usually the contacts on any of the controls are "gold anodized" to allow for minimun resistance.
#7
01-30-18, 05:01 PM
Group Moderator
Do you have a voltmeter ?
The next step is to check the output of the thermopile. It needs to be better than 500mvDC (1/2 vdc). That must be checked before assuming it's a bad valve.
The next step is to check the output of the thermopile. It needs to be better than 500mvDC (1/2 vdc). That must be checked before assuming it's a bad valve.
#8
01-31-18, 10:59 AM
Again, your help is so much appreciated!
I do have a voltmeter that will read voltages that low, so I will definitely check that.
The thermostat is as old as the furnace, and has worked okay. I've been wondering if there is a way that a bad thermostat could cause the pilot to go out.
I've run the pilot adjustment screw all the way in clockwise, and many turns out (I think that nine is the maximum), and there is no change in flame size.
I do have a voltmeter that will read voltages that low, so I will definitely check that.
The thermostat is as old as the furnace, and has worked okay. I've been wondering if there is a way that a bad thermostat could cause the pilot to go out.
I've run the pilot adjustment screw all the way in clockwise, and many turns out (I think that nine is the maximum), and there is no change in flame size.
#11
01-31-18, 09:34 PM
Group Moderator
500mv is good. Not sure what you mean by closed circuit.
As of late 2016 that valve is still available or a replacement for it from Cozy.
84086 DEXEN LP WALL VALVE
It looks like Cozy only sells to the trade. You may have to call different fireplace companies to locate parts.
As of late 2016 that valve is still available or a replacement for it from Cozy.
84086 DEXEN LP WALL VALVE
It looks like Cozy only sells to the trade. You may have to call different fireplace companies to locate parts.
#12
02-01-18, 03:22 AM
If you are looking to buy a new gas valve, you could go to the Robertshaw company site and look for gas valve model "359-812-490A" for LP. gas. It may not be an exact match by size but will get the job done. On their web site they can show where you can buy this valve. You can also check with a local Johnstone supply outlet for a Cozy replacement.
#13
02-01-18, 06:51 AM
Even more helpful advice. My thanks. The 500 mv was the voltage at the terminals while the thermopile was installed in the furnace and keeping the pilot valve open (as opposed to removing it and testing it with a separate flame as some apparently recommend). I didn't know if that would affect the reading or not.
I have been able to identify and locate a source for two valves that would be suitable. I guess my plan at this point is to try to nurse it through the rest of the cold season and replace the valve in the spring. I am going to get the valve and have it on hand in case the other one gives out completely.
I have been able to identify and locate a source for two valves that would be suitable. I guess my plan at this point is to try to nurse it through the rest of the cold season and replace the valve in the spring. I am going to get the valve and have it on hand in case the other one gives out completely.
