cross connection

i hope someone out there can help out with this one. about a month ago i installed a new 50gallon gas hot water heater for a women. water heater was working fine until 3 days after, she called complaining that she did not have enough hot water in her shower. after checking things out, i found a significant, cross connection at the jucuzzi tub. i then shut the valves that feed that fixture off, in the basement. problem solved, until she was ready to change out the fixture. so i thought. she had no problems for 3 weeks.until i received a call again. assumming the valves i turned off had leaked by, i went over there confidently to fix the problem. well thats not it. i found 1, 2handled faucet in the same bathroom as the jucuzzi, and one single handled delta in the laundry room that were cross connecting, and the problem is still not solved. i've checked every fixture in all 4bathrooms, incuding even removing the dip tube from the water heater and tested the water pressure.this house is only one floor so all the piping is visable in the basement.it all loooks pretty normal to me,there are no mixing valves on toilets nothing out of the norm. also the women states shes never had the problem until the water heater was changed. so, in a nut shell, certainly i can't shut half of this womens house down. so if anyone has any suggestions i would greatly apprieciate it.

Hi Ttrist07 welcome to the forum. I hope you will like it here.

Before trying to help could you please explain what a 'handled faucet' means? (English isn't my motherrtongue and I have not heard this word before except in the form of faucets for turning on the water).

I am also not sure that I understand you about the 'cross connection' thing. Where does this cross connection happen? (I'm sorry I just can't draw a picture in my head by what you mean)

i apologize for not being so clear, i should say a widespread facuet in the lav, and delta 100 in the laundry room. and if i new where the cross connection was coming from i wouldn't be asking for help????

Call me dumb (yes, you are permitted to do so) but how do you know it's a cross connection then?

because cold water is back feeding thru the hot water line and into the water heater. i know this because, i have shut the cold feed to the water heater, and removed the vacuum breaker. then water will poor out the top. when i shut both the hot and cold feed to these two fixtures, it will stop the water from overflowing the water heater. but the problem re-occurs as soon as i re-assemble everthing. im only making the assumption it's a cross connection, but the water has to be back feeding from somwhere.

I am new here, and I see this thread is five months old, but never answered. As I understand the problem, ttrist07 has a situation where, if he shuts off the cold water feed to the water heater, then removes the output connection from the water heater (which would be hot water supplying the house), water flows from the hot water feed line. I am assuming this is pressurized supply water, not simply water draining from the system.

I would suggest diverting the hot water feed to a suitable drain, then go through the house and turn off the hot water supply valve to each faucet and device (dishwasher, washing machine, bath tub, sinks, etc.) At some point, the flow of water from the hot water feed line will stop. That will identify your culprit.

However, a "cross connection" in a faucet is almost impossible without water coming out of the faucet as well. The few places I've seen it occur are in places like washing machine valves and things like toilet mixer valves to prevent the toilet from sweating.

Barnmichael, welcome to the forum I am so happy you joined us! Thank you very much for this valuable information, sir. I hope ttrist will read this soon

cross connections are common in faucets, it's just like a shower, it has a mixing valve. happens all the time.