# What is it? Test your diagnostic skills.



## Protech (Sep 22, 2008)

Honeywell zone valve on an active direct solar water heater loop. Valve is just under 3 years old.

What do ya think? What is it?


----------



## Protech (Sep 22, 2008)

more


----------



## Lifer (Nov 23, 2010)

OK ...I'll bite my guess would be calcium or lime .. not normally a problem till yea heat them up ?... 
am I close?


----------



## Titan Plumbing (Oct 8, 2009)

Excessive flux


----------



## ToUtahNow (Jul 19, 2008)

Leaking exchanger?


----------



## Protech (Sep 22, 2008)

System is active -direct. No exchanger.



ToUtahNow said:


> Leaking exchanger?


----------



## greenscoutII (Aug 27, 2008)

My guess, it looks like calcium......


----------



## Protech (Sep 22, 2008)

ya, calcium buildup from having the circulation controller set way too high. 200 degrees


----------



## RealLivePlumber (Jun 22, 2008)

Love the new avatar. 

Looks like me at the keyboard some days.


----------



## vinpadalino (Aug 27, 2010)

Looks like a Honeywell zone valve beat to ****.


----------



## Conte Plumbing (Dec 20, 2010)

Is it hard or soft?
Did you have to scrape it with a chisel or wipe it out with a rag?


----------



## Protech (Sep 22, 2008)

Hard


----------

