We have (4) HW/HWB 670 gas-fired commercial biolers in our plant. One of them, the pilot light keeps turning off about once or twice a day. We have to go and reignite it. We have tried testing it by shutting off the gas and restarting it. We have noticed the pilot light goes off once every 5 tries. It as though the gas to the pilot light is also shut off. Do you have any idea what could be causing this? The unit works fine except for the pilot light turning off every now and then. Also I have not been successful in trying to find a company that is familiar with these units. Would you know of any. We are in La Prairie, Quebec, about 4 km south of Montreal. Thank you very much. Look forward to hearing from you.