DHW Question

[mattcav1]

I have searched but am unble to find an expert answer to my entire question so here it goes.

I have purchased a house with a WF Premier unit Open Loop system. It has DHW with 2 electric hot water heaters attached. Both water heaters are 50gal units with dual elements there are 6 people in the house The WF loops to the 1st tank and then the 2 tanks are attached together. I live in northern Indiana. Here are the questions i need answers to so i stop obsessing.


Do i leave the electricity hooked up to the first "Buffer" tank?

If i do what do i set the thermostats to in the first "buffer" tank?

What do i set the thermostats to on the second "finish" tank?

Are there different times of year that i should have the buffer tank electricity hooked up like during high heating demand season or middle of the summer?

I appreciate any help anyone can provide me.

[urthbuoy]

Leave first tank off.

2nd tank is whatever you like your hot water at. 120F to 160F.

If you were running out of hot water in this setup, you could turn on the first tank, but you will limit the usefulness of the DSH.

[docjenser]

I second Chris' comments. In addition you can flip the breaker on/off for the 1st tank when your demand is too high and the buffer tank is not getting any noticeable hot water products from the heat pump due to low run times. Just don't forget to flip it off when run times increase, otherwise you don't get much benefit from you desuperheater.

[engineer]

Ditto.

I favor setting finish tank thermostats as low as possible, consistent with comfort, ideally no higher than 120*F

I imagine a household of 6 has to work around limited hot water storage, especially during spring / fall when geo and desuper operation are limited.

You could set the buffer tank elements to an intermediate temperature, 90-100 to extend system capacity while preserving some heat storage capacity for the desuper. If you do that, consider a timer to limit operation of the buffer tank elements to just those hours of peak hot water use.

All that said, any operation of buffer tank elements will compromise DSH effectiveness, as has been written.