Can't get shop heater working
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Can't get shop heater working
Story is my grandpa had a old modine hanging heater he had sitting around for 20 years. He was going to use it for when he built a garage but gave up and gave it to me for winter. Got gas line run to it and wired up but the pilot lite won't stay lit. Fan and all the electrical parts seem fine. He didn't have the valve covered so it had a lot of crud in it.
Well he took it apart and cleaned it out and still doesn't work. Replaced the thermocupling and pilot still goes out. He got a new valve and still the same problem. When we take the part the thermocupling goes into out and heat it with a torch the switch will stay in and then click back out when we remove the heat off of the coupling, but when we put it back into the valve it still acts like the thermocupling isn't getting hot enough to keep the switch tripped and it's bright red.
We're thinking we might have just got a bad valve but is there something else that we're missing here to why the pilot won't stay lit?
Well he took it apart and cleaned it out and still doesn't work. Replaced the thermocupling and pilot still goes out. He got a new valve and still the same problem. When we take the part the thermocupling goes into out and heat it with a torch the switch will stay in and then click back out when we remove the heat off of the coupling, but when we put it back into the valve it still acts like the thermocupling isn't getting hot enough to keep the switch tripped and it's bright red.
We're thinking we might have just got a bad valve but is there something else that we're missing here to why the pilot won't stay lit?
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From: Douglas, Georgia
have you cleaned the pilot oriface? (it's really tini so be careful not to damage it).
also on the modines, you can adjust the pilot... perhaps set the flame a little higher.
on alot of my old units (I've got 7 of them) I've had to move the pilot light/bend the thermocouple so it is in better contact.
Also make sure the gas line is bled out enough. When you first hook up a heater there will be alot of air in the line at first.
drew
also on the modines, you can adjust the pilot... perhaps set the flame a little higher.
on alot of my old units (I've got 7 of them) I've had to move the pilot light/bend the thermocouple so it is in better contact.
Also make sure the gas line is bled out enough. When you first hook up a heater there will be alot of air in the line at first.
drew
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From: "Islander"
Make sure you match the thremocouple to the gas valve as older heaters had 900 milivolt thermocouples and newer around 400-450 milivolt. Use a D cell battery to see if the gas valve opens, do quick short connections. Best to work with a DVM.
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The heater and valve are both set up for natural gas. We found the pilot adjustment and its turned up as far as it would go. We didn't know that the milivolts were different for the older models and probably have the wrong one. Will check on that. Thanks
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Post Fiend
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From: "Islander"
When your dealing with milivolts (small scale), any resistance or corrosion at connections or thermostat wire will kill the voltage to the valve.
Did you do a momentary contact with a 1 1/2 volt flashlight battery to see if the valve functions?
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Did you do a momentary contact with a 1 1/2 volt flashlight battery to see if the valve functions?
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Post Fiend
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From: "Islander"
Now you need to check the thermocupling for voltage output with a digital meter while your in the start (hold **** down) mode, thermo in the flame. Check the model number to see if it's generating the correct output and if the it's compatible with your gas valve.
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Mountain Pass
Joined: May 2001
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From: MT
A normal thermocoupler is around 30 millivolts while a thermopile or a millivolt genarator is around 750 millivolts..Is this a millivolt or a 24volt system?..Does the thermostat run off millivolt or 24 volt?..It can make a big difference in what the problem could be..If a 24 volt I would say weak pilot holding coil in the GV or (and I have seen it before) a bad thermocoupler out of the box..Or does the GV have a adaptor where the thermocoupler screws into, are there two wire leads coming from that area that may go to a tripped high limit..If a millivolt system, using a thermopile or millivolt genarator to power the system, then as "Beemer Nut" says check for corrosion in conections, and that the thermostat is a correct one for millivolt system, also check to see if the thermopile or genarator you are using is the correct one for the GV..Since you have tried a new GV that will work when you heat it with a tourch I would check for the correct millivolts and make sure the pilot flame is in about the middle of the thermocouple or thermopile..I am more of a hands on person so I may have left something out but let us know what you find..
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From: MI
Originally Posted by Beemer Nut
Make sure you match the thremocouple to the gas valve as older heaters had 900 milivolt thermocouples and newer around 400-450 milivolt. Use a D cell battery to see if the gas valve opens, do quick short connections. Best to work with a DVM.
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power and pilot generators connect by wires and usually have standing pilots that have a hand valve to turn them on and off, the generator is used to open the main valve.
Last edited by Crash687; Dec 16, 2005 at 05:26 AM.
Post Fiend
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From: "Islander"
Correction on early post, thermocouple output 30 mv, sorry. Far as a generator pilot producing 250 mv that's BS as Granger sells a generator with pilot made by White Rodgers model# PG9A38JTL24 with a output of 750 mv not 250 mv.
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Posting Guru
Joined: Mar 2004
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From: MI
Originally Posted by Beemer Nut
Correction on early post, thermocouple output 30 mv, sorry. Far as a generator pilot producing 250 mv that's BS as Granger sells a generator with pilot made by White Rodgers model# PG9A38JTL24 with a output of 750 mv not 250 mv.
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http://www.white-rodgers.com/pdfs/04...Cat_pg_081.pdf
infromation on your PG9A38JTL24:
http://www.white-rodgers.com/pdfs/04...Cat_pg_082.pdf
When calling someones BS please be prepared to back with facts.