Hot water temperature not staying consistent

[safehaven]

Hello,

We have a new to us Greenline 48 Coupe and we have a situation where when using hot water it will stay consistent temperature but seems to be when the pressure take drops and calls for the water pump to turn on we get cold water for about 30 seconds before the hot water comes back. Not fun in the shower. Was wondering if anyone ever had anytihng like that and if it may be a problem with the pressure tank.

Thanks

 

[RT Firefly]

Greetings,
Welcome aboard.

 

[Bmarler]

Dang, that’s not a pleasant thing is it? I think you should provide a little more info. What type of shower mixer? I like the ones that have a lever for temp and a lever for on/off/volume. But, some of these may be problematic in some instances as they try to maintain the temperature, but need some water to flow before they stabilize.
30 seconds seems like a long time though, that’s a lot of wasted water.

 

[O C Diver]

If the system has a pressure switch, it most likely has a pressure tank with an air bladder. The bladder may have failed or the air pressure may not be correct, which could cause the problem.

Ted

 

[READY]

Does the boat have a tankless hot water heater (as opposed to a traditional hot water heater? If so that unfortunately is the problem. It only heats when water flows and thus it pushes out some cold water everything it cycles off (due to tank pressure valve closing).

You probably would need to bypass the pressure tank.