Suburban SW6P won't operate... thermocouple issue??

Pilot flame models

When you turn knob to pilot position and light it you are bypassing safety device when pushing/holding knob down.
Pilot flame gets thermocouple hot which then sends a millivolt signal that energizes/holds magnet open allowing gas flow to pilot flame.

Your pilot flame is staying lit so thermocouple is functioning, magnet is being energized and MAIN Gas should flow
(Magnet is safety device......not energized/held open no pilot/no main gas)

No main gas..
Then remove main orifice and clean it by soaking in alcohol then blowing it out with air (no poking things thru hole)
Clean burner tube.......small bottle brush thru it or push cotton ball/piece of cloth thru it----air blowing will NOT get rid of spider webs which can completely disrupt gas flow

IF still having main flame issues...........gas control (valve defective)

Provided you have correct LP Pressure (11" WC with at least 50% of propane appliances in service---otherwise weak regulator)

vlopddap wrote:

I totally agree with your opinion because I am not sure neither how the thermocouple is working exactly in the overall operating sequence. But in my opinion it certainly have something to do with the burner control valve too (not only pilot), as you don't want your water heater burner to "switch on" gas if the pilot light have died! So the thermocouple surely have something to do directly with the burner control valve at some point. Are you not agree?

I do some searches on Google about this issue and I found two threads from other forum where people reported similar issue (where pilot light, but main burner won't turn ON) and they both finally pointed to a defective thermocouple/pilot assembly.

I also found a thread where the guy reported that the pilot light outlet where misaligned with the thermocouple rod and provide a bad heating. I am not sure exactly because it's a pretty tight space to look at, but maybe at some point my pilot outlet may been bend a little bit during the ignition process... I am trying to figure out what is the relation between the thermocouple and the main burner gas control valve here...

I certainly would expect the pilot going out to shut off all gas to the burner, both the pilot and the main burner. I assume (but do not know!) that it just shuts off all the gas at the input, at least on the controls I've seen for water heaters, but perhaps it's not that simple.

If others with similar difficulties have found that replacing or adjusting the thermocouple have solved the issue, then that doesn't seem like a completely silly thing to try.

DrewE wrote:
If the thermocouple were not warm enough, wouldn't it shut off the pilot flame? I kind of thought that's how water heater controls usually worked, and that's why you have to hold the pilot light knob/button for a spell after first lighting the pilot. I may very well be mistaken, though.

It sounds to me more like a problem with the thermostatic gas control valve, maybe something sticking internally. If it were me, I'd probably chat with the clerk behind the counter at some local appliance repair place or gas company for their opinion given the symptoms.

I totally agree with your opinion because I am not sure neither how the thermocouple is working exactly in the overall operating sequence. But in my opinion it certainly have something to do with the burner control valve too (not only pilot), as you don't want your water heater burner to "switch on" gas if the pilot light have died! So the thermocouple surely have something to do directly with the burner control valve at some point. Are you not agree?

I do some searches on Google about this issue and I found two threads from other forum where people reported similar issue (where pilot light, but main burner won't turn ON) and they both finally pointed to a defective thermocouple/pilot assembly.

I also found a thread where the guy reported that the pilot light outlet where misaligned with the thermocouple rod and provide a bad heating. I am not sure exactly because it's a pretty tight space to look at, but maybe at some point my pilot outlet may been bend a little bit during the ignition process... I am trying to figure out what is the relation between the thermocouple and the main burner gas control valve here...

If the thermocouple were not warm enough, wouldn't it shut off the pilot flame? I kind of thought that's how water heater controls usually worked, and that's why you have to hold the pilot light knob/button for a spell after first lighting the pilot. I may very well be mistaken, though.

It sounds to me more like a problem with the thermostatic gas control valve, maybe something sticking internally. If it were me, I'd probably chat with the clerk behind the counter at some local appliance repair place or gas company for their opinion given the symptoms.