Nordyne M1M Low Flame Blinking Yellow Light
Posted: Thu Oct 15, 2009 4:01 pm
Hi All,
I have a problem with this unit. It is a three/four year old M1M with A/C. What happens is, I can hear the combustion fan run and the ignitor lights up, there is a blue flame, the yellow light blinks continuously and the flame goes out in about 30 seconds or less. The main blower runs after a moment or so before the flame goes out. It then starts the routine again in a few minutes. The flame seems small and not intense enough to be right. There seems to be just about 24 volts to the Gas Control Valve while the flame is present. Before I start trying to take a guess, I wanted to run this one by a few more knowledgeable people. The stack seems clear BTW. No real bad soot inside either. The Gas Stove works just fine, so there is probably gas available. I don't have a manometer handy, so can't say for sure what the pressure is. The unit ran fine before the beginning of the last A/C season.
I'm wondering what to look at or fix or replace. I'm looking seriously at the gas control valve. It's a Robertshaw 7200 DERC. I think it might be that it is designed to start out with a lower flow and it never makes it to the higher flow level. The Ignitor glows white hot and the flame lights when gas is present. The flame seems small and much lighter than I would expect. I'm also thinking that there might be a sensor near the ignitor, but can't really tell unless I start tearing this thing down. The system has not been used this season for heat and this is the first time it was started up in heat mode.
My main problem is I'm about 100 miles away from the unit at the moment, so I don't have it in front of me for exact model numbers.
Some history about the system. It has been a problem since day 1. The A/c unit had to be replaced right after installation, since it did not operate properly. It had a leak in the A/C system as well. Before the beginning of this past A/C season, the thermostat was replaced and the Capacitor on the compressor was replaced. The heating part of the system worked fine for two seasons. The system appeared to work fine after the thermostat was replaced. It was done since the old unit was using batteries and needed frequent replacement. The new one uses the "common" wire and runs off of the 24 volt supply, rather than batteries.
I would also need a resource to find the actual part numbers of the parts other than the control valve.
I have a problem with this unit. It is a three/four year old M1M with A/C. What happens is, I can hear the combustion fan run and the ignitor lights up, there is a blue flame, the yellow light blinks continuously and the flame goes out in about 30 seconds or less. The main blower runs after a moment or so before the flame goes out. It then starts the routine again in a few minutes. The flame seems small and not intense enough to be right. There seems to be just about 24 volts to the Gas Control Valve while the flame is present. Before I start trying to take a guess, I wanted to run this one by a few more knowledgeable people. The stack seems clear BTW. No real bad soot inside either. The Gas Stove works just fine, so there is probably gas available. I don't have a manometer handy, so can't say for sure what the pressure is. The unit ran fine before the beginning of the last A/C season.
I'm wondering what to look at or fix or replace. I'm looking seriously at the gas control valve. It's a Robertshaw 7200 DERC. I think it might be that it is designed to start out with a lower flow and it never makes it to the higher flow level. The Ignitor glows white hot and the flame lights when gas is present. The flame seems small and much lighter than I would expect. I'm also thinking that there might be a sensor near the ignitor, but can't really tell unless I start tearing this thing down. The system has not been used this season for heat and this is the first time it was started up in heat mode.
My main problem is I'm about 100 miles away from the unit at the moment, so I don't have it in front of me for exact model numbers.
Some history about the system. It has been a problem since day 1. The A/c unit had to be replaced right after installation, since it did not operate properly. It had a leak in the A/C system as well. Before the beginning of this past A/C season, the thermostat was replaced and the Capacitor on the compressor was replaced. The heating part of the system worked fine for two seasons. The system appeared to work fine after the thermostat was replaced. It was done since the old unit was using batteries and needed frequent replacement. The new one uses the "common" wire and runs off of the 24 volt supply, rather than batteries.
I would also need a resource to find the actual part numbers of the parts other than the control valve.