Cannot get hot water in shower

[Aaron31]

I have installed a new hot water tank, I have a circulation system as well that continuously pumps water throughout the lines. I get hot water in all bathroom sinks, however if I run bath water it only comes out a extremely hot and you cannot cool it down, but when you pull the knob to turn on the shower then the water comes out hot and fades into ice cold after about a minute, however if I take the shower head off then the water comes out extremely hot and it wont get cool unless I put the shower head back on. I have bought several shower heads and tried them but it does the same thing with each shower head. Also it does this in all 4 bathrooms. so im left with either extremely hot bath water or a cold shower, there is no in between. I have called 2 different plumbing companies to come and fix it and neither of them could help. They would just charge me for the service call and pretty much say good luck. any help would definitely be greatly appreciated.

 

[Phog]

If i understand correctly, you had a working plumbing system in the house, with working recirculation, and have simply replaced the old hot water tank with a new one? Nothing else except the hot water tank changed from the previously working system, yet now all the shower fixtures, and ONLY the shower fixtures, are not working right? Every other plumbing fixture in the house continues to function properly?

 

[Sponsor]

 

[hj]

They should also have changed the check valve in the recirulation line a the water heater.