Pilot wont stay alight - Water Heaters

The system I am familiar with uses a vapour pressure type thermocouple and if the pilot remains lit the thermocouple is working as it controls the gas for the pilot and the burner at the same time from the same source - if the gas control is ok and the flow isn't prevented by the thermostat then if the pilot remains alight, there should be a flow of gas and the burner should light - unless the gas jet is blocked or something else, some other type of blockage is preventing the flow of gas to the burner...

I suggest you check the gas jet and the flow of gas to it...

These are designed not to light once the thermocouple fails.the thermocouple has a small wire that positions in to the pilot light which checks the pilot is on and keeps the gas governed.once the temperature drops it shuts off the gas to prevent a build up of gas in a room where a pilot light has gone out.this is why you need to hold the button in on reignition to allow the thermocouple to heat up so the gas keeps open.
Try to relight by turning on the gas ....pressing down and holding the button for at least 10 seconds whilst firing the piezo to ignite flame.do not release gas button for at least 10 seconds then slowly release.if the flame on the pilot will not stay alight....then it is likely the thermo has failed.try cleaning the metal wire that is above the pilot jet.still no joy then it needs replacing.hope my comment is of help...please vote.

Get more air to the unit.
http://waterheatertimer.org/pdf/Bosch_Ventilating_tight_houses.pdf
http://waterheatertimer.org/pdf/Attic-Ventilation-and-Pilot-Outage-in-Gas%20Water-Heaters.pdf
Don't use household vent fans.
Trim back trees, and move stuff away from front of water heater and from around vent pipe.
Pilot outage can be caused by tightly insulated house, poor upward draft on flue, other vents or vent fans drafting air upward and causing downdraft on water heater, wind coming down flue pipe, water dripping down flueway, dirty combustion parts, clogged pilot orifice, failed thermocouple, failed gas control valve, low gas pressure, water or air in gas line, super hot location ... or combination of more than 1 thing.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

there should be a flap or removable tray on bottom of boiler, under this you will find a large button, push in and hold press the igniter button a few times until pilot can be viewed through window. continue to hold it in for 12 sec and release slowly checking pilot is still alight. there may even be instructions on flap or tray.

The pilot light jet may have got a little bit of dirt or grit in it which is preventing it from keeping alight. Try probing the jet with a fine piece of wire to see it the blockage can be dislodged. You may have to unscrew the jet to clear it by blowing air through it. Make sure gas is turned off first before removing any parts.

The pilot light also has a thermocouple that allows gas to the pilot light while the flame is burning. If flame goes out it shuts gas off to the pilot jet. The thermocouple is bypassed by a switch during the initial ignition and once the thermocouple warms up after a minute or two of holding in the bypass switch, it should maintain the pilot. If, after cleaning, the pilot light keeps going out, it would seem that your thermocouple is faulty and needs to be replaced

The pilot light jet may have got a little bit of dirt or grit in it which is preventing it from keeping alight. Try probing the jet with a fine piece of wire to see it the blockage can be dislodged. You may have to unscrew the jet to clear it by blowing air through it. Make sure gas is turned off first before removing any parts.

The pilot light also has a thermocouple that allows gas to the pilot light while the flame is burning. If flame goes out it shuts gas off to the pilot jet. The thermocouple is bypassed by a switch during the initial ignition and once the thermocouple warms up after a minute or two of holding in the bypass switch, it should maintain the pilot. If, after cleaning, the pilot light keeps going out, it would seem that your thermocouple is faulty and needs to be replaced

turn and push in button on your honeywell gas valve hold it in and spark lighter cont to hold for 20secs then ease finger off button very slowly pilot sould stay alight if not try again in 2mins best of l;uck

If the thermocoupler is defective the gas to everything is shut off. The coupler is the bulb that sits ib the pilot flame If it doesn't heat up it will sense no pilot and shut the gas off. They don't cost much and are easy to change. Good Luck, Ned

hello!! if you changed the thermocouple & the pilot still goes out !! could be a thermostat ( the electromagnet pilot safety ) goes bad !! make sure pilot is clean & should be sharp BLUE pilot !! not yellow & soft !! also hold down the button light the pilot use a digital volt meter set on dc milivolts a brand new thermocouple should test @ 30 milivolts+ - ! & if you have new style water htr with sealed combustion the thermocouple has a safety part of it ! change the thermocouple & make sure your vents for combustion air around the bottom of the water htr has lint & dust built up !!! kiddbrother i work for a gas company doing service !!