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View Full Version : Why is my NEW 30gal water heater turning the supply cold after little use?


67Stanger
Jan 11, 2009, 01:09 PM
I recently replaced a 30gal water heater in a hair/nail salon shop with a GE(Rheem) 30gal from the Depot. I did nothing more than remove and replace the unit along with a new shut off valve that was located on the hot side.

Let me explain the water heaters use per shop. The shop is two shops combined. The nail side where I replaced the water heater feeds 4 pedicure tubs, 1 small sink in a waxing room and 1 head washing sink in a back room that I don't think is really used much. The hair side of the shop has a 50gal water heater that feeds 3 head washing sinks, 2 small bathroom sinks and a washing machine that they only use cold water to wash their towels. But the hot line goes up through the ceiling from this 50gal tank and before it runs to the nail side fixtures, it splits out and runs over to the hot side of the 30gal tank.

This line connecting from the 50 to the 30 hot side comes in right at the shut off I replaced and then below that is the 'T' that feeds the fixtures on the nail side of the shop.


So here is my problem: The HOT water on the nail shop fixtures, mainly the pedicure tubs, isn't staying hot enough for long. The shop owner has turned the thermostat all the way up to 160 degrees. When you run the hot water in the tubs, it will come out hot for a bit, but it will start to get cool and not stay hot. Unless of course it sits for a bit. So I'm not sure if the thermostat is bad on the new unit or if the other line coming in from the 50gal unit is somehow messing this up. I only replaced what was already there with the 30gal unit and that one shut off valve (which is open - have tried it closed and still same result). Not sure why that is fed over from the other side anyway (I assume to pick any slack, but it obviously isn't working now). By the way, the hair side of the shop is not affected.

Greatly appreciate any feedback on this headstumper. OUCH!!

Scott

hvac1000
Jan 11, 2009, 01:44 PM
It is possible that the water heater has a dip tube problem. This will allow the heater to work but it will only put out hot water for a short time since the cold water is not being directed to the bottom of the tank. The bad dip tube will allow the cold water to mix with the hot water at the top of the tank causing the problem. Now how it is all plumbed is any ones guess from here.

How to Repair a Broken Dip Tube (http://www.ronhazelton.com/tips/repair_broken_dip_tube.htm)

Gas Water Heaters - Problems and Solutions (http://www.chilipepperapp.com/gwh.htm)

How a water heater dip tube works and what it looks like. (http://www.masterplumber.net/electricwh/dip_tube.htm)