Water mixing valve issue

[slash007]

I found today that my spot free holding tank water was hot. Traced the pipes and it seems that there is a mixing valve that is supposed to keep the water at 80 degrees. I'm assuming it failed as there are both cold and hot water going into it, but only hot coming out. Any benefit to warm water for the spot free? Any issues leaving it hot until I get it fixed? I need to decide if I get rid of the mixing valve and just go cold (soft) only, or replace it and keep it warm. In the meantime I left the water hot, but can turn off the boiler if hot water will hurt the membranes.

Thanks!

 

[cantbreak80]

Most TF membranes are ok up to about 113F. Beyond that...they might deteriorate quickly.
77F is the optimum operating temp. Colder water incrementally reduces output.

Reliable tempering valves can be expensive. Supplyhouse.com is a good source

 

[slash007]

Thanks for the information. I keep the water at around 103, so that shouldn't be an issue. This one lasted 16 years, so would be nice to get the same out of another one.

 

[cantbreak80]

I like this one. https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Watts-0559116-Product_Overview.pdf

I installed it on my home's DHW system last year. The boiler heats the indirect water tank to 150F. The mixing valve supplies 120F water to the faucets. (yeah...I'm a little paranoid/obsessed about Legionnaires disease).

The manufacturer recommends occasional service....clean the inlet filter screens. With the union connections its a snap to perform.
A temp gauge on the mixed outlet would help you keep an eye on it.

 

[slash007]

Good idea, and thanks for the link. Any idea what goes wrong with them? Any chance I could fix what I have? Never messed with one before and no idea how they work.

 

[cantbreak80]

slash,
Beyond cleaning the inlet screens and check valves, I’m not aware of repair parts being available.

If you have interest in an hour of informative reading:

https://www.caleffi.com/sites/default/files/coll_attach_file/idronics_22_na.pdf

https://www.watts.com/dfsmedia/0533dbba17714b1ab581ab07a4cbb521/8722-source/f-mxv