Lite On Heating & Cooling - Recent Questions, Troubleshooting & Support

Short pilot blocked not heatinhg thermocouple or thermocouple needs changing

Maybe bad thermocouple. Replaced or clean

possibly a fowled thermocouple if the thermocouple doesn's sense the pilot flame then it will not send a signal to the gas valve telling it that its okay to open cause the pilot is lit.

check to make sure that the poilet lite flame is touching the tip or top of the thermocouple.the pilot lite needs to heat up the thermocouple so that the thermocouple opens the gas to the main gas log. a cold thermocouple shuts off the gas to the main gas log or gas burner and a hot thermocouple opens the gas to the main burner.the pilot lite flame must be touching the thermocouple to heat it up.pilot lite orface needs to be clear to let the pilot flame gas through with enough pressure so that the little flame can reach & touch the thermocouple. Pilot lite gas feed tube must be clear to let gas through. Use compressed air or a fine sewing needle, or even carb cleaner to clear out orface hole and gas feed line to pilot lite.important!! WARNING: if you use carb cleaner,make sure all the carb cleaner is dry,soaked up with paper towell or kleanex tissue and blowed out with compressed air , because carb cleaner can burn just like gasoline; so any carb cleaner must be compleatly gone before you attempt to lite the pilot lite.

the thermocouple not only keeps the pilot on but lets the gas valve know its okay to open on a call for heat, remove your thermocouple and clean it with a fine grit sandpaper and if this doesn't work replace it all together.

If the pilot flame is not strong enough, it will not tell the gas valve to open, or if the gas valve is not getting the signal to open, it won't. Check all wire connections at the thermostat and gas valve. Check ground wires. Clean the pilot light and flame rod.

Check the sand filter is not blocked Check the pump size is ok for the filter size Pit your multiport to recirculation to give the boiler full pump presure. You may have a pressure switch fault

You have to push in on it to move to 'pilot' If you need further help, I’m available over the phone at https://www.6ya.com/expert/craig_3fa289bf857b1a3c

you might need to bleed the line to get fuel to the heater core. If there is a bubble in the line it will prevent the heater from working. Usually, there is a bleeder valve on the heater unit -- unscrew this and let some of the fuel drain out (into a container) and give it another shot. It should light right up after bleeding the line. If the fuel that you took out of the bleeder valve looks clean, you can then put it back in the fuel tank and it should be fine.
If this is a natural gas heater, there will be no bleeder valve -- you should have it looked at by a professional repair person. Natural gas is very dangerous and should only be repaired by a qualified professional to avoid serious injury or death.