Tempra 24 24.0 kW tankless water heater modification

Thread Starter


Joined Oct 2, 2014
I have a
Stiebel Eltron
Model # Tempra 24
Tempra 24 24.0 kW Whole House Tankless water heater. I want to install a on delay relay from the flow switch so unit will not run for 5 or so seconds after flow is sensed. This is to alleviate the problem of a quict turn on to rinse hands and the unit starting and not actually getting hot water to the faucet. Bill way too high.


Joined Oct 23, 2010
Dave has the optimum plan.
Train users to use cold water tap instead of hot unless they absolutely want/need the water heated.

I have a whole house electric water heater and think it is an efficient way to go.
People can be trained.

Now if you set the delay to 10 min that might help users to get the idea. Forced training.


Joined Mar 14, 2008
Any delay on the turn-on of the water heater will just waste water when you actually want hot water.

I vote will all the rest. Use the cold water faucet if you aren't going to wait for hot water. If necessary, to train others in the house, post a sign. ;)