customer wanted me to check his fireplace. the thermopile was putting out in between 420-480 MV. i jumped out the gas valve and it wouldnt fire.
i put in a new thermopile and let it warm up. had a reading of 375 MV. the box saids its a 750 MV thermopile. i jumped the gas valve and it fired right up.
how many MV is normal to be generated from these things. made sure pilot was clear and burning good.