shot of hot water from cold water taps

[De.windhoos]

My apologies for my non-responsiveness but I had a projectlist longer than the boat, only 2 weeks and desperately wanted to get some sailing time before flying home again.

By your comments it looks like the non-return valve sometimes gets a little stuck, I will have a look and see if I can disassemble and clean when I’m back on the boat in 2 months

Thank you for the input and advice.

[inspectr]

Further to my last post on the subject, it is more likely to happen if your cold water input line is off a "Tee" connection and the cold water line continues to the offending fittings, rather than the heater being at the end of the cold water line.

In other words the PRV is not working so a little hot water backflows and gets into the cold water line at the Tee and then comes down the cold line.