I never realised how inefficient / expensive to run a Gulfstream was until I replaced it...

.... with a more tradional combi.

After just over a month (ok short period) I have noticed a 35% saving on gas consumed compared to the same period last year. The energy (gas) consumed to keep the store at temp 24hrs a day soon runs up the gas bill.

I would recommend anyone with a faulty gulfstream cuts their losses and replaces it, rather than throw good money after bad. You should get payback within a couple of years through savings on fuel and spare parts.

Good point.
What combi did you have fitted?
Mike