Blodgett mo # 981 will not start all the time

Okay, I know this question was asked last year but maybe someone will see this answer and get some help from it. If there is no pilot check to see if gas is present at the pilot assembly when you press the red button on the safety valve. The tube running from the safety valve to the pilot assembly may be clogged, unscrew the tube from the safety valve and push in the button you should be able to determine if gas is coming through. The safety valve is the one with the red button that you hold in when lighting the oven, it has a flame sensor piece that sits directly next to the pilot flame. That flame sensor has to get bright glowing red before the safety valve will open, if it is not positioned in the right place by the pilot flame or if your pilot assembly has gotten clogged and is not putting out a strong enough flame the sensor will not get hot enough. If the sensor is glowing bright red and the oven is not lighting, check the gas pressure before and after the safety valve to determine if the valve is letting gas through. If the safety valve is letting gas through the next piece is a simple on-off knob that you turn to open the gas line (and I am sure you made sure this was open didn't you?!) if you are not sure check the gas pressure before and after that valve. There are small plugs in the gas line that can be removed to measure the gas pressure you want about 3.5 wc for natural gas and usually around 7 wc for lp gas. The last step is the thermostat and if the safety valve is working properly then your thermostat is probably the problem, make sure it is calling for heat (turned up) and take a wire brush a scrub out the burner holes around the pilot flame, if the burner still wont light you need to replace your thermostat. Okay, I know this question was asked last year but maybe someone will see this answer and get some help from it. If there is no pilot check to see if gas is present at the pilot assembly when you press the red button on the safety valve. The tube running from the safety valve to the pilot assembly may be clogged, unscrew the tube from the safety valve and push in the button you should be able to determine if gas is coming through. The safety valve is the one with the red button that you hold in when lighting the oven, it has a flame sensor piece that sits directly next to the pilot flame. That flame sensor has to get bright glowing red before the safety valve will open, if it is not positioned in the right place by the pilot flame or if your pilot assembly has gotten clogged and is not putting out a strong enough flame the sensor will not get hot enough. If the sensor is glowing bright red and the oven is not lighting, check the gas pressure before and after the safety valve to determine if the valve is letting gas through. If the safety valve is letting gas through the next piece is a simple on-off knob that you turn to open the gas line (and I am sure you made sure this was open didn't you?!) if you are not sure check the gas pressure before and after that valve. There are small plugs in the gas line that can be removed to measure the gas pressure you want about 3.5 wc for natural gas and usually around 7 wc for lp gas. The last step is the thermostat and if the safety valve is working properly then your thermostat is probably the problem, make sure it is calling for heat (turned up) and take a wire brush a scrub out the burner holes around the pilot flame, if the burner still wont light you need to replace your thermostat.