Problem getting full hot from faucet

[Desi501]

Hello, I have a somewhat strange problem. I own a single floor, 1250SF home built on a slab in Florida. In the master bedroom bath mostly, if I turn on the faucet to full hot I get warm only. If I leave it running and go to the tub 5 feet away and turn it on full hot for 3 to 5 seconds, the faucet water turns hot. I get the same issue in other rooms to a lesser degree.I have even tried shutting the cold supply off altogether and still only get warm. I have replaced the faucet with no change.

Can anyone point me in the right direction with this.

 

[Jadnashua]

Do you have a hot water recirculation system? IF you do, the cross-over valve may be defective.

 

[Sponsor]

 

[Desi501]

Do you have a hot water recirculation system? IF you do, the cross-over valve may be defective.

Not sure what that is but I have a regular electric hot water tank one line in, one line out and a blow off line.

 

[Smooky]

What faucet did you replace?

 

[Desi501]

What faucet did you replace?

The one at the bathroom sink off the master bedroom. That was the one giving me the most problem even though they all do it to some degree. That one is the furthest away from the hot water tank.

 

[Smooky]

A cross flow can happen at single handle shower faucets if the faucet is worn or maybe if not installed correctly. Also if you add an extra shut off on the shower that can cause this problem. (The shower valve is the most likely cause)..... A “Y” connect hose on a hot and a cold faucet can cause this problem too. There are other reasons too.

 

[Desi501]

That makes some sense. I don't recall the setup behind the wall in the shower/tub but the shower control has been there for about 7 years and the problem has only shown up in the last 6 months or so. The originally plumbing is about 35 years old.

 

[Smooky]

Is it a single handle shower or what?

 

[Desi501]

Is it a single handle shower or what?

Yes, it is. A Kohler

 

[Smooky]

You may have to take it apart to figure out exactly what you have. Replace all the internal parts of the shower valve.

http://www.us.kohler.com/us/search/commonPartsResults.jsp?searchTerm=Shower%20Valves&pageName=maintenanceLanding

 

[Desi501]

You may have to take it apart to figure out exactly what you have. Replace all the internal parts of the shower valve.

http://www.us.kohler.com/us/search/commonPartsResults.jsp?searchTerm=Shower%20Valves&pageName=maintenanceLanding

Yes, it looks like the GP77759

 

[Desi501]

Yes, it looks like the GP77759

It looks like Home Depot has it in stock so I will pick it up tomorrow.
I want to thank you for all your help. I'm an auto tech and I help people on a forum also so feel free to drop by http://autoforums.carjunky.com/

 

[Smooky]

When you pull that part out there will be a pressure ballancing unit behind that. You will need to replace everything.
Here is a simular valve with diagrams and pictures:
https://terrylove.com/forums/index....hler-rite-temp-bath-shower-valve-k-304.41581/

Kohler Rite-Temp , Cap and PBU
https://www.youtube.com/watch?v=YZ3RY5hFRrc

http://www.us.kohler.com/us//productDetail/shower-valves/637966.htm?skuId=613412&hash=id%3Dfilters-1%26startIndex%3D40%26scrollTop%3D760

 

[Desi501]

When you pull that part out there will be a pressure ballancing unit behind that. You will need to replace everything.
Here is a simular valve with diagrams and pictures:
https://terrylove.com/forums/index....hler-rite-temp-bath-shower-valve-k-304.41581/

Wow, that pressure balancing unit is even more money than the outer valve. Home depot seems to have both in stock. I looked upo the combo part number but Home Depot only shows the mixing block on that part number. Either way they have what I need.