Kitchen mixer issues

[rally]

We have a Furrion insta hot ( not a fan) so the hot water works perfect in Bathroom shower and sink however the kitchen is a different story the hot water starts hot then if you turn it off and then back on it turns cold for a bit then hot again. Like it cold waiting on hot to arrive. Mixer valve on faucet maybe?

[Jkwilson]

My guess would be the water heater isn’t turning on the second time. Why, I can’t guess.

[JBill9694]

We also have a tankless water heater. Once you turn it off, the fire goes off but the fan continues to blow to clear the exhaust fumes out. Turn it back on and the heater has to sense water flowing before it begins the ignition cycle. I believe this is why you're getting the cold water when you re-open the valve.