Water temperature fluctuations

[brent84ty]

I recently removed an old fiberglass tub/shower insert in order to build a new walk in tile shower. I had a plummer come in to move the drain, raise the faucet handle height, and raise the shower head a bit. After he was finished we noticed the "hot water" was only luke warm. Warm enough not to be miserable in the shower but not by any means hot. At times when you first turn on the hot water it comes out scalding hot before turning luke warm. Every faucet in the house is affected and is not isolated to one room or the other. The hot water heater is electric and only 4 years old, replaced it myself. I called the plumber back and he returned to change the heating elements. We continued to have the same issue. Rather than have another service call fee, I changed out the thermostats myself. Still no change. Also to note is I have the luke warm water from the hot faucet but have cold water in the cold faucets. Any ideas?

 

[SHEPLMBR]

Do you have single handle fixtures?

 

[brent84ty]

The showers are single handle fixtures. The kitchen and two bathroom sinks have dual handle fixtures.

 

[brent84ty]

Also this morning I noticed that when multiple faucets are running in the house, the hot water faucet in the kitchen runs ice cold.

 

[gargalaxy]

Can you check for leaks?

 

[brent84ty]

From what I can tell under the house, there don't appear to be any leaks.

 

[SHEPLMBR]

Could be the cartridges. On the shower most have a limit stop to keep the water from getting too hot. If none of those do you have a mixing valve on your water heater?

 

[frodo]

shower/tub valve mixing valve

scald guard/ water tempering adjustment needs adjusting

if moen, behind the handle.

delta, lil screw top left behind face plate


scald guard works by mixing cold with hot, to much cold will be a cross water situation