Mr Pink outranks me on seniority so I will cowtow if forced to here...
The problem isn't the QEV
All the QEV does is control how fast and where the gas vents. Your problemis input, not exit. All our team run Planet QEVs, fitted by me or Your-MUM. There's no disadvantage, and the primary advantage is gas effienciency, and it's not slight - but I know I should do proper tests to tell you how much better it is than use vague similes.
John C also massively outranks me and I don't know much about anything but I do know about Ions, hence I diagnosed something that SP still can't explain and that I can, and that every SP tech I've spoken to can't diagnose but I did (magnetic bracket).
John C's right. Main reg. That's all...
Love to all, as ever