water temperature issue

[trshot]

I'm having an issue with my Bosch 660EF on demand water heater. I'm getting water that is not hot enough from faucets/showers. I attached a hose to the output side of the service port and i get a whopping 130 degrees of discharge as its set for that and a full flame in the box, normal functioning right? When I close the service port and open the house supply I'm only at 80 degrees with full flame in the box to the house!
The supply for the house and the service ports are an integrated fixture with the house supply immediately below the service port. I removed the fitting and both ball valves are working and nothing being restricted for flow to the house,. If I open the service port along with a nearby faucet I'm getting 80 at faucet and 130 from service port, I'm truly baffled, any help is most welcomed to figure this out, thank you.
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[Twowaxhack]

Shut the cold water off to the water heater.

Now, go to the kitchen faucet and turn the faucet on to the hot side.

Once the pressure is bled off, the water should stop.

If it doesn’t stop then you have cold crossing over into the hot side some where. It’s called a cross connection.

 

[trshot]

Shut the cold water off to the water heater.

Now, go to the kitchen faucet and turn the faucet on to the hot side.

Once the pressure is bled off, the water should stop.

If it doesn’t stop then you have cold crossing over into the hot side some where. It’s called a cross connection.

I think you got it, i did that and with my H side open it never bled off and water kept running. What's next, I have two mixing valves (sink, shower) are they usually the culprits where all the others are separate H & C valves?

 

[Twowaxhack]

Are you leaving any faucets on with a handheld shower with a positive off function ?

Go around and make sure all your faucets are off at the valve.

Do you have a hot water circulation system ? Hot water pump and bypass valve ?

 

[trshot]

Shut the cold water off to the water heater.

Now, go to the kitchen faucet and turn the faucet on to the hot side.

Once the pressure is bled off, the water should stop.

If it doesn’t stop then you have cold crossing over into the hot side some where. It’s called a cross connection.

Bingo, you called it!

 

[trshot]

Bingo, you called it!

Hot water is now hot again, cross connection found, thank you for your help!!