Fogged up glass

[Gareth Paul Williams]

Good evening oven cleaners,
Cleaned an oven a few days ago, got a call to say the glass had fogged up with a layer of white powder! Went straight over and cleaned it again. The glass was covered with a film of some sort of white substance. A cloth and glass cleaner didn't shift it, only came off when I used some pink stuff.
Glass is now perfect again, customer is happy but I've no idea what caused this.
4 years doing this and I've never seen this happen before. I don't dip the glass and I don't use caustic oven cleaner.
What are your thoughts on what could have happened here??

 

[Paul Dennis]

Did you notice if customer uses those silver grey trays ? I had one similar few years back , oven was perfect when I left then 2 days later white pale coating all over , I asked if they used the tray I spotted on the side and they baked fish on the tray in the base of the oven , it coated everything .

 

[Gareth Paul Williams]

Did you notice if customer uses those silver grey trays ? I had one similar few years back , oven was perfect when I left then 2 days later white pale coating all over , I asked if they used the tray I spotted on the side and they baked fish on the tray in the base of the oven , it coated everything .

I didn't see any trays like that, but definitely think it might have been something the customer did. I feel much better blaming the customer.