I purchased/installed the Big Maxx MHU80 in my shop last year, it ran fine all winter and spring. I turned if off for a few summer months and now it won't start up. It has natural gas supply, the inducer motor comes on, the ignitor comes on, but no flame. The gas valve does not click or make any noise while the ignitor is engaged and there is no sound or smell of gas. My error code flash is two after the third attempt to ignite a flame. I tapped the gas valve with a wrench while the ignitor sequence was in progress. I suspect the gas valve is not working. Is there another way to confirm it's the gas valve, or are there any other suggestions on what I might try to get it running. Thanks.
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Mr. Heater Big Maxx MHU80 - gas valve functioning?
- Thread starter kheaps
- Start date
fitter30
Well-known member
Hot surface igniters work by amperage. The board is looking for a minimum amps before gas valve process starts. Pull the igniter take it to a appliance parts store they should be able to match it. If the plug is wrong just splice your plug or use wire nuts. Then go back if it works for a spare. You can call the tech line for the amps but they might tell you.
I purchased/installed the Big Maxx MHU80 in my shop last year, it ran fine all winter and spring. I turned if off for a few summer months and now it won't start up. It has natural gas supply, the inducer motor comes on, the ignitor comes on, but no flame. The gas valve does not click or make any noise while the ignitor is engaged and there is no sound or smell of gas. My error code flash is two after the third attempt to ignite a flame. I tapped the gas valve with a wrench while the ignitor sequence was in progress. I suspect the gas valve is not working. Is there another way to confirm it's the gas valve, or are there any other suggestions on what I might try to get it running. Thanks.
Can you test for voltage at the gas valve?
I have never seen a furnace or heater control board look for amps on the ignitor. I could disconnect the ignitor and the heater would go through the sequence, open the gas valve, then finally go out on flame failure.Hot surface igniters work by amperage. The board is looking for a minimum amps before gas valve process starts. Pull the igniter take it to a appliance parts store they should be able to match it. If the plug is wrong just splice your plug or use wire nuts. Then go back if it works for a spare. You can call the tech line for the amps but they might tell you.
fitter30
Well-known member
Page 38 HSI current lowCan you test for voltage at the gas valve?
I have never seen a furnace or heater control board look for amps on the ignitor. I could disconnect the ignitor and the heater would go through the sequence, open the gas valve, then finally go out on flame failure.