Hot then Cold Shower !

[sv.gypsysoul]

We have a shower that runs hot then cold then hot again. I have tried adding a pressure tank in case it was the pump cycling that caused the problem, but that didn't work. Sure would love to take a hot shower when we have been motoring enough to make hot water, but this is torture! Any ideas?

[captain465]

I had the same trouble with the system on my boat. I replaced the pump I had, a pump with an accumulator (pressure tank), to eliminate the noise of the pump cycling. The pump I put in, a Shurflow VSD (variable speed displacement) pump, and not only did I get rid of the noise, but it eliminated the "temperature surging", and made showering a very pleasant experience again.

[osirissail]

I have the exact same problem when I take a shower in the morning. I fixed it by smacking the first mate on the side of her head and told not to turn on the water in the galley when I am in the shower.

[YOGAO]

We had this problem on our boat and fixed it by installing a check valve on the cold water line coming INTO the hot water tank. This prevents any water that makes it to the hot water tank from flowing back to the cold water feed to the shower.

I might have pictures somewhere, let me know if you need em.

Fair Winds,
Mike

[gettinthere]

my problem is that with the shower only, I get a surge of cold water each time I turn on the shower wand during a shower. Doesn't happen anywhere else!

[osirissail]

A ha, now I see, said the blind man. The surge of cold when turning the shower head/wand on and off is not "fixable." The skinny size of the hose and its easy ability to "dump heat" is what causes this situation. There is no fix other than to let the water run continuously. The water piping in a boat is normally smaller than in a house so dissipation of heat is more rapid.

[Mark Zarley]

We solved the hot and cold problem. We adjusted the water heater thermostat to a confortable setting and only turn on the hot water when showering. This eliminates the "cold shot" that occurs when turning it on and off, that you get when showering with "mixed" water.