Step up transformer that sounds odd. have you worked on this stuff before? Why do you want to change the way they are set up now?

Yes I have. Not a Pro but the Pro's replaced Four Bad Units in another building (at 800 a Pop+ Installation) that I took the " Bad One's" and cleaned the pilot tube out with a Q-Tip and they work just fine now. I don't use terms like "You All" because there are many reputable guys out there.
Transformer looks like a 24VAC transformer reversed (where 24V is the primary) and is feeding the module 120 volts but not the true 120 volts that they were made for.
I would like to convert them to the same 24 V DSI's. If that means changing them to 24V valves then that is what I will have done. That's one less thing to go bad.
Six bad 120v modules tells me something is wrong with that set up.
I can't see any reason to spend $3000 + Installation when 6 modules will run around $800 + Installation. Can anyone?
I know on my furnace after the igniter lights the flame and the flame sensor shuts it off neither glow or continue to glow red hot. This leads me to believe that the spark and sensor assembly may be to close to the flame.
When servicing anything I believe in looking for the underlying reason of problem to begin with and not just getting it to work. Thanks for your concern for safety