If I let go of red button flame goes out even after several minutes

check gas pressure if ok check burner tube for blockage

Not familiar with this machine but found this
http://vintageshasta.proboards.com/thread/64
If you look / click at the high res versions of the pages it tells you; that you should hear a click of the safety valve after a short time lighting it. If the click is not heard, then the main gas safety valve will not open fully and the flame will go out.
This is a sure sign that the Thermostat .burner unit needs to be replaced.
See the manual pages and you;ll see what I mean.
From other postings I have seen the best place to get spares for these things is on Ebay.
Good Luck

Lea, the problem is not the gas control valve. It's the Thermocouple that needs replacing. When the Thermocouple fails, the pilot flame will not stay lit. The Thermocouple is a safety feature that stops the gas, if the pilot flame goes out for any reason. If you've never replaced it before, I'm surprised the original one has last for 10 years.

Hope this helped you solve the problem.

You will need to replace the pilot safety or commonly called Thermocouple. It is the probe located in the flame disc and works its way back to the gas valve. Remove it and take it to a good hardware store. You may have to purchase a longer one but you can keep it coiled to make it fit. Real easy to replace.

First, turn off the gas valve for at least 5 min and ventilate the room. Most wall heaters are lit the same as a water heater. Find a red button to push or turn the gas valve knob to the pilot position. While pressing the red button or the gas valve knob, hold a match to light the pilot flame. After it lights continue holding the knob for one or two minutes. If the flame goes out when you release the knob the thermocouple is probably bad.

Hi you will need to replace the thermocouple. This is the copper tube that screws in to the gas valve and goes back and mounts along side of the pilot. Most will pull straight out. When they go out, the pilot will light when you hold the red button down, but as soon as you release it off it goes. You can but this thermocouple at any hardware store. They come in different lengths, But I would get a 36" one. They will coil up so they wont be in the way. Its better to have a longer one then one that's to short. Make sure the tip is in the flame, or it will do the same thing. It has to get very hot to keep and produce milivolts to keep it on.Please don't forget to rate me on this as I know you will be kind. This will solve your problem for sure.
Sincerely,
Shastalaker7
A/C, Heating Contractor

Hello KJGreen, It sounds, based on your description, as though the thermocouple is faulty and should be replaced. If the pilot light stays lit and you've left it on for several minutes before turning the knob on to light the log set, then that indicates that the thermocouple is bad.

The thermocouple is a safety device (heat sensor) designed to stop the flow of gas to the burner in the event the gas flame goes out and the pilot goes out. The sensor will only allow the gas valve to open once it has reached the preset temperature.

To confirm that the thermocouple is defective, I would light the pilot light and allow it to remain lit for up to 10 minutes before I attempted to turn on the log burner. If, after 10 minutes, the log burner still won't stay lit, then you know that the thermocouple needs to be replaced. Otherwise, the burner should light, since after 10 minutes, the sensor should be hot enough to signal the gas valve to open.

If you are going to have this replaced, please make sure you use only an approved supplier, since an incorrect replacement part could cause an unwelcome malfunction of the gas log burner. Safety should be primary when dealing with open flame burners.

Hope you find this Very Helpful and best regards!

The question is? I'll assume you cylinder is the water heater, right?
On the heater (water) you will find or see the red controls and a sheet metal cover over a hole. Remove the cover and this is where you light the pilot light. Press down on the red dial and turn it to pilot. In that position you will be able to press the red button . Geyt a long match or bbq lighter, then, holding down the red button dow for a minute or so and place a match or lighter into yhe area where the lines go The flame will catch the gas and lite the pilot if yo simply move your glame around. When the flame catch on the pilot, continue holding the button down for sveral minutes until the buld the flame isheating gets hot. Then release the buton and turn the main dial to on. The main burner should fire up. If not, and the pilot goes out, repeat the process. The bulb in the pilot flame is a thermocoupler that shuts all gas off if it doesn't detect a pilot flame, so hold the button down longer. If the pilot goes out when you release the button, The thermocoupler is no good and needs replacing. Good Luck_Ned_

The flame should cycle on and off in response to the thermostat. If it is going out and not coming back on several minutes later then the exhaust vent may be clogged. Check the lint filter and exhaust vent all the way to the vent outlet to make sure they are not clogged.

Faulty gas valve coils are the typical cause of this type of "cycling". These electrical coils are right above the gas valves and when energized, these solenoids open the gas valves and permit the burner to light. If any gas valve coils are suspected of being faulty, it is recommended that both (all) be replaced at the same time. Hope this helped and best wishes.