Mendota Seabrook DV D-40 pre 2004 and 2004+ gas valve failures
Over the last week have ran into 3 D-40 seabrooks that were not lighting the main burner. Initially I thought it may be a thermopile so checked millivolts on the thermopiles 500mv+ with pilot on, then checked connections, dissasembled connections added a brand new thermopile connection and hit with pilot no bueno.
So jumping the valve while getting the correct millivolts didn't do anything, on one of them it kicked on then died out, So on each occasion called tech to make sure was doing the right tests to verify that gas valves indeed were faulty. I understand Gas valves are heavily misdiagnosed and wanted to make sure I wasn't throwing parts at the problem. The only other tests would be ohms on the valve and or applying the famous 9v to jump or shock it open
The weird thing for me and what caused me to call tech on 3 separate occasions was the fact that the same model on 3 systems in a week have went down and it seemed pretty odd. Question? With your experience guys when these valves go down what would be the ultimate verification of failure beside the tests performed above?
Have a cool one
Make sure the front left log is not sitting directly on the thermopile generator. I had two of those do that in the last 3 weeks. One was a brand new installation. Either cut the back of the log out for clearance or prop it up slightly. Both solutions worked for us. Both solutions were confirmed as fixes through Mendota technical.
Notice: Advice given is general in nature. Local laws and ordinances may govern and/or supersede the information and recommendations provided. Final determinations are the responsibility of a local qualified industry professional with first-hand knowledge of the situation, and the AHJ.
Tried it, most of the time have the logset out of the box when I am testing components. Found that if I don't being in the vicinity of my clumsy hands they will break(: In trade was taught that looking at symptoms is not correcting the primary problem. Yes the gas valve has failed but its kinda of irking me why it failed and not being able to figure it out. Stuck valve walk away but been looking around for nomenclature to primary causes for failures. In AC/Heating was told the manufacuers express that compressor failure is misdiagnosed highly, gas valves probably are in that same category.