Three showers in the house all go cold after 5-6 minutes and then goes back to normal after about 30 seconds. Nobody is turning on the hot water somewhere else in the house while taking showers so that is not the problem. Have never heard of this problem before. The valves are moen château so there is no pressure balance. Help!

Was there any plumbing work done in your house lately ? Also, do you have Tankless Hot Water heater installed ? Do you have Hot Water Circulation Pump installed on your hot water plumbing ? Please, answer these questions. Back to you. Milo

The house was just puchased recently. The house has been sitting for a year. No hot water circulation pump. It has 2-50 gallon gas water heaters connected in sequence. They are both new. Thanks

connected in sequence. And would that sequence be in series or parallel? Are both heaters turning on at the same time? Back to you. Tom

Cold water goes into the first heater , then out of the hot into the second heater and then into the hot water lines. It's in series.

Cold water goes into the first heater , then out of the hot into the second heater and then into the hot water lines. It's in series. Are both heaters operational? Could heater #2 be malfunctioning? Back to you. Tom

They are both brand new gas heaters and they are both working.

Does this happen with all faucets or just the shower valve> Let me know, Tom

Only the showers

I'd start by replacing the cartridge, Moen will send you one fro nothing. Just call
Call: 1-800-BUY-MOEN (1-800-289-6636)
8:00 am to 8:00 pm Monday through Friday
8:00 am to 6:30 pm on Saturdays EST
Closed on Sundays and all nationally observed holidays.
To contact Moen Canada call: 905-829-3400 m Good luck, Tom

OK, Thanks for the Info - Dave Neill

You're welcome! Let me know if that works out. Good luck, Tom